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. 2023 Feb 22;18(2):e0266576. doi: 10.1371/journal.pone.0266576

Informal sector employment and the health outcomes of older workers in India

Poulomi Chowdhury 1,*, Itismita Mohanty 1, Akansha Singh 2, Theo Niyonsenga 1
Editor: Simona Lorena Comi3
PMCID: PMC9946227  PMID: 36812213

Abstract

A large proportion of the older population in India constitutes an undeniable share of workforce after the retirement age. This stresses the need to understand the implications of working at older ages on health outcomes. The main objective of this study is to examine the variations in health outcomes by formal/informal sector of employment of older workers using the first wave of the Longitudinal Ageing Study in India. Using binary logistic regression models, the results of this study affirm that type of work does play a significant role in determining health outcomes even after controlling socio-economic, demographic, life-style behaviour, childhood health and work characteristics. The risk of Poor Cognitive Functioning (PCF) is high among informal workers, while formal workers suffer greatly from Chronic Health Conditions (CHC) and Functional Limitations (FL). Moreover, the risk of PCF and/or FL among formal workers increases with the increase in risk of CHC. Therefore, the present research study underscores the relevance of policies focusing on providing health and healthcare benefits by respective economic activity and socio-economic position of older workers.

Introduction

Globally, ageing population has become a common phenomenon owing to reduction in fertility and mortality rates, and these integrated effects have altered the age-sex composition as well as labour force participation towards higher ages [1, 2]. Speculation indicates that the world population aged 60+ will be around 2 billion in 2050 from 900 million in 2015 [3]. By 2050, nearly 80 percent of the older population will reside in low-middle income countries [3]. Ageing process in developed nations has slowed down the economic growth through insufficient labour force. These nations have implemented policies aiming to boost labour force market by motivating the older population to work past the age of 65 years [410]. Consequently, in recent years, the share of older workers has amplified substantially in developed nations [4, 5, 7, 913].

Apart from these nations, the developing countries are also experiencing shifts in age-structures with a tremendous pace. United Nations (UN) report (2017), states that almost 60 percent of the older people are currently living in developing countries, and is growing rapidly compared to developed countries [14]. Alas, the provision and implementation of pension benefits or retirement programs are less prevailing in developing nations. Apparently, only 20 percent of this population is entitled to any pension related benefits, yet most of them rely on family support system [15]. Accordingly, significant proportion of older people are active in labour market in developing countries [2, 1620] than developed countries [21].

India, the second most populous nation in the world, is also facing remarkable increase in ageing population, reportedly 8.6 percent (104 million) of the total population in 2011 [22]. This figure is expected to escalate to about 20 percent and, in terms of absolute numbers, the country will be a home for 319 million older individuals by 2050 [23]. Soon this older population will surpass the young population below 14 years [24].

Ageing is normally associated with chronic health conditions which upsurge later in life [22, 2527]. As evident from prior studies, more than half of the older people endure non-communicable diseases (NCDs), while one-fourth are affected by multimorbidity [28, 29]. Across India, these chronic diseases exhibit huge heterogeneity in terms of socio-economic conditions, place of residence and gender [22, 26, 30]. Further, estimated figures suggest that the burden of NCDs will constitute a large share of the national disability [31]. Projected numbers demonstrate that roughly 45 percent of the health burden will be borne by older people [32, 33], making the health requirements of older people comparatively higher than other age groups.

Specific social security, poverty alleviation and social welfare programs have been launched to address the challenges associated with older population’s social and health conditions. Certain policies and programs implemented by the ministries, namely, National Policy on Older Persons, National Social Assistance Programme, National Policy for Senior Citizens, Indira Gandhi National Old Age Pension Scheme, and Mahatma Gandhi National Rural Employment Guarantee Scheme, have failed to offer adequate financial assistance to support the older persons’ requirements, particularly to those in unorganized working sector and below poverty line [3436]. Rashtriya Swasthya Bima Yojana was also introduced to provide health insurance to the workforce engaged in unorganized sector but unable to perform well because it failed to capture below poverty line families, tribal blocks, and impoverished sections of the society [3739]. To achieve the sustainable development goal of universal health coverage, the government of India has approved Ayushman Bharat Yojana (ABY) in March 2018. It is an ambitious scheme to provide financial health protection for 500 million Indian population belonging to vulnerable sections. However, like every health program in India, the success of ABY lie on overcoming existing issue like public and private sector governance, quality control, stewardship and health system organization [40].

Unfortunately, the majority of the Indian older population are unable to access healthcare services after the retirement age (60 years and above) due to paucity and poor coverage of universal health and pension programmes. Therefore, to manage the livelihood and healthcare needs, older people are compelled to work after the retirement age [19, 41]. Census of India (2011) figures illustrate that a large proportion (33 million) of older people are working after the retirement age, especially in informal sector. However, informal sector provides financial support to only marginal level of workforce after the retirement [20]. Even in formal sector, nearly 10 percent of the population engaged in selected organized work places receive the benefit of social or voluntary health insurance schemes [42]. The absence of proper financial and health care schemes can hamper the health conditions of older people indulged in economic activities. It makes older workforce as one of the most vulnerable groups in India.

Thus, given the rising magnitude of older workers, it becomes essential to understand the extent to which their health conditions are associated with the type of employment. However, no studies till date, nationally or internationally, have emphasised on this aspect. Keeping this in mind, the present research focused on health outcomes/conditions, specific to older workers who are engaged in formal and informal sector of employment. It hypothesized that people engaged in informal employment work will experience more unfavourable health outcomes, that is, high rates of chronic health conditions, functional limitations, and poor cognitive functioning, compared to those in formal sector of employment. Research findings will help in addressing the important policy issues considering the extent of variation in health among older workers in India [41, 43].

Research framework

Persisting health problems among older people constitutes a longstanding concern for researchers and policy makers as the prevalence of morbidity is relatively high in later ages. It is acknowledged that older people continue to participate in the labour force despite of the health risks and socio-economic challenges, particularly in developing nations [2, 19]. Kalwij, Kapteyn (2016) stated that health is multidimensional in nature and the effect of the work engagement on health varies with health indicators assessed. Evidently, prior studies have discovered that work engagement has a pronounced effect on physical [11, 12, 4450] and mental health [1012, 4648, 5052]. Few studies asserted that engagement in low paid jobs negatively influences physical health of the older people [12, 44]. Besides, working longer with degraded health conditions can have severe repercussions such as the need for long-term care, mental health issues and functional disability [11, 12]. Nevertheless, prolonged older age work engagement has also a beneficial effect on mental health [1012, 47, 50]. This holds true in the study of Japan and Korea which describes that working in later life is generally associated with financial security and strong social network leading to better cognitive functioning and less depressive symptoms [11, 50]. However, the relationship between type of work and health could also be affected by self-selection bias in which a person may self-select into the type of work due to pre-existing health conditions, even from younger age. Meaning that there may be two-way relationship where the pre-existing health conditions influencing the type of employment and vice versa. In the case of India, the self-section into poor jobs is implausible because formal and informal sector types of work encapsulate a broad range of occupations. While individuals might select the type of occupation (within the formal or informal sector) due to their pre-existing health status, it is unlikely that they will select between formal and informal sector activities and continue to do so at an older age.

The relationship between work engagement and health conditions may vary by type of occupation [51, 53, 54]. This relationship is also shaped by various socio-economic and demographic attributes [2, 5, 12, 1820, 44, 51, 52, 55], work characteristics [11, 12, 5557], lifestyle behaviours [11, 16, 5759] as well as childhood health conditions [60]. Altogether, previous studies reflected a robust relationship between work engagement and health, and taking these into account, a research framework has been conceptualized. In addition, strong relationships within health indicators also have been described in previous studies. For instance, chronic health conditions (CHC) amplifies the functional limitations [16, 49, 61, 62], and influences cognitive functioning of older people [11, 49, 51, 63]. However, the functional limitations and poor cognitive functioning are closely related to each other, as evident from previous studies which reported that physical disabilities or functional limitations increase the risk of poor cognitive functioning in older persons. Indeed, Rajan, Hebert (2013) [64], Chodosh, Miller-Martinez (2010) [65] elaborates that functional limitation plays a key in amplifying the risk of cognitive decline through neurodegenerative processes. Likewise, poor cognitive is associated with high likelihood aggregated functional limitations [6668]. McGuire, Ford (2006) mentioned that older people with lower level of cognitive are more likely to become physically disabled than those with high cognition. Based on the findings of these studies, the combined variable of poor cognitive functioning and/or functional limitation is constructed to search for a stronger relationship between type of work, physical and cognitive functioning. As discussed above CHC may influence the functional limitations as well as poor cognitive functioning, and could modify the association between type of work, functional limitations, and poor cognitive functioning. So, the effect moderation of CHC on type of work and other health-outcomes has also been assessed in the study. The research framework reflecting the relationships between type of work and health outcomes is depicted below (Fig 1), along with adjustment factors, including childhood health, lifestyle behaviours, socio-economic and demographic characteristics as well as work characteristics.

Fig 1. Research framework.

Fig 1

Note: Blue line represent moderation process.

Materials and methods

Study design

The present study has employed nationally representative data of Longitudinal Ageing Study in India (LASI). It is based on a cross-sectional design as it uses only one wave (baseline currently available) of the LASI data.

Data source

The LASI baseline survey (2017–18) was conducted with the joint collaboration of International Institute for Population Sciences, Harvard TH Chan School of Public Health, and the University of Southern California [69]. This LASI survey followed a multistage stratified cluster sample design and collected information on 72,250 Indian adults aged 45 years and above, across all states and union-territories. Out of which, the sample in this study contains 31,464 older individuals (60 years and above) where around 10,746 older people (60 years and above) are currently engaged in the workforce.

The LASI survey aimed to collect the longitudinal data of older adults which include the information on social and economic wellbeing, burden of diseases, functional health and healthcare based on internationally comparable research design and tools. It created a foundation for reliable and acceptable data for national policy and long-term scientific research. Further, it provided in-depth information of economically active older population, workforce participation across older ages and different sectors, perceived economic security, work characteristics, vulnerability, and expectations.

Outcome variables

Following the research framework, the present study has emphasized on four health outcomes i.e., chronic health conditions (CHC), functional limitations (FL), poor cognitive functioning (PCF) and PCF and/or FL. Details of these health outcomes are given below:

1. Chronic health conditions

The CHC is summarized using nine self-reported health conditions. These health conditions are hypertension, diabetes, cancer, chronic lung disease, chronic heart diseases, stroke, arthritis, neurological problems, and high cholesterol. The format used in the questionnaire is “Has any health professional ever diagnosed you with any of the chronic conditions or diseases……?”. Based on this information, CHC is categorized into 0 (none) and 1 (at least one health condition), where 0 labeled as ‘No’ and 1 as ‘Yes’.

2. Functional limitations

The FL is constructed using 13 everyday activities which are generally termed as activities of daily living (ADL) and instrumental activities of daily living (IADL). Out of the 13 activities, the first 6 are related to ADL, while 7 are associated with IADL. The question format of FL is “Because of health or memory problem, do you have any difficulty with any of the activities…?”. The FL is dichotomized as 0 (no limitations) and 1 (at least one limitation), where 0 labeled as ‘No’ and 1 as ‘Yes’.

3. Poor cognitive functioning

For the assessment of poor cognitive functioning health outcome, the present research has followed the LASI report which uses the cognitive module of Health and Retirement Study (HRS) involving memory (0–20), orientation (0–8), retrieval fluency (0–61), arithmetic function (0–9), executive function (0–4), and object naming domains (0–2). First, these indicators are normalized by employing following formula:

observationiminimummaximumminimum,fori=1,2,.,n10,746.

This normalization helps in rescaling the indicators between 0 to 1 [70]. Then, a principal component analysis (PCA) is applied to create a composite score of cognitive functioning, where minimum score represents poor cognitive while higher score reflects better cognitive functioning [71, 72]. This score is further divided into three equal parts (tertile groups), where first tertile is coded as 1 (to represent poor cognitive) while rest are coded as 0 (otherwise).

4. PCF and/or FL

The PCF and/or FL variable is constructed by combining Poor Cognitive functioning and Functional limitation health outcomes. Below is description of PCF and/or FL:

PCF_FL=1,ifPCF=1and/orFL=10,otherwise

Type of work

LASI survey follows International Classification of Occupation 2015 to categorize the occupation types. These categories are further grouped into formal and informal work based on the guidelines provided by 66th round of National Sample Survey Organization report which adopts the National Classification of Occupation 2004 [73, 74]. The type of work variable is dichotomized as 0 (formal) and 1 (informal).

Other independent variables

As per the research framework, four main dimensions of covariates are considered, that is, socio-economic and demographic, work characteristics, life-style behavior, and childhood health. Socio-economic and demographic dimension includes gender (male, female), age groups (60–65, 65+), caste groups- based on the access to wealth, power and privilege (general, Scheduled Tribe (ST), Scheduled Caste (SC), Other Backward Class (OBC)), religion (Hindu, Muslim, others), educational level (low, middle, high), marital status (currently married, others), place of residence (rural, urban), wealth (low, medium, high), and household size (1–3, 4–7, 8+). Work characteristics include working hours per week (less than 24 hours, 24–48 hours, 48+ hours), duration of being in current work (less than 15 years, 15–30 years, 30–45 years, 45 years and above) and monthly wages. The life-style behavior variables are drinking alcohol (no, yes), smoking/consuming tobacco (no, yes), physical activities consisting vigorous activities (never, rare, everyday), moderate activities (never, rare, everyday), and yoga/pranayam (never, rare, everyday). Childhood health variable includes 5 categories (very good, good, fair, poor, very poor) which have been recoded as 1. Good/fair (very good, good, fair), 0. poor (poor, very poor). Apart from these variables, the region is also taken as independent covariate which involves North (Jammu & Kashmir, Himachal Pradesh, Punjab, Uttarakhand, Haryana, Delhi, Rajasthan), Central (Uttar Pradesh, Chhattisgarh, Madhya Pradesh), East (Bihar, West Bengal, Jharkhand, Odisha), North-East (Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura, Meghalaya, Assam), West (Gujarat, Maharashtra, Goa), South (Andhra Pradesh, Karnataka, Kerala, Tamil Nadu, Telangana), and Union territories (Chandigarh, Daman & Diu, Dadar & Nagar Haveli, Lakshadweep, Puducherry, Andaman & Nicobar).

Statistical analysis

Descriptive summary statistics were compiled using proportions and means with associated standard deviation. The study utilized bivariate analysis with chi-square test of association and multivariable analysis following the research framework to investigate the relationships depicted in the conceptual framework (Fig 1).

First the percentage of formal and informal older workers aged 60 year and above are calculated by socio-economic and demographic variables. Then, the prevalence rate of CHC, FL, PCF and PCF and/or FL are calculated by type of work and chi-square test is applied to measure the significance of association. Lastly, sequential multiple logistic regression models are employed as the outcome variables are dichotomous. In the first model (Model-1), chronic health conditions (CHC) outcome is the function of type of work only, while in the second and third models, the effect of type of work on CHC is assessed by controlling for socio-economic and demographic variables (Model-2), and work characteristics, life-style behavior, childhood health and regions (Model-3) respectively. For functional limitation (FL) outcome, Model-1 includes the type of work and CHC residual, while in Model-2, the interaction term CHC residual*Type of work is added along with socio-economic and demographic indicators. Selection of CHC residual as a control is done by exploiting control function approach suggested by Wooldridge (2015) [75], there by instrumenting the CHC residual for model-3 in Table 1. Similarly, Model-3 adjusts for work and life-style characteristics, childhood health and regions, as in the case of CHC. For PCF, PCF and/or FL, the same procedure is followed as in case of FL. Below is the description of all models by health outcomes (Table 1), following the research framework (Fig 1).

Table 1. Description of logistic regression models.

Outcome variables Independent variables
Model-1 Model-2 Model-3
CHC TOW TOW, SED TOW, SED, WC, LSB, CH, Regions
FL Res_CHC, TOW Res_CHC, TOW, Res_CHC*TOW, SED Res_CHC, TOW, Res_CHC*TOW, SED, WC, LSB, CH, Regions
PCF Res_CHC, TOW Res_CHC, TOW, Res_CHC*TOW, SED Res_CHC, TOW, Res_CHC*TOW, SED, WC, LSB, CH, Regions
PCF /and FL Res_CHC, TOW Res_CHC, TOW, Res_CHC*TOW, SED Res_CHC, TOW, Res_CHC*TOW, SED, WC, LSB, CH, Regions

Notes: CHC: chronic health conditions; FL: functional limitations; PCF: poor cognitive functioning; TOW: type of work; SED: socio-economic and demographic variables; WC: work characteristics; LSB: lifestyle behavior, CH: Childhood health; Res_CHC is obtained from logistic regression model-3 of CHC i.e., CHC–CHC_cap

Results

Descriptive analysis results

Table 2 shows that approximately one-third of the older population is currently working, out of which 73.1 percent are engaged in informal employment activities. Moreover, in terms of unfavorable health outcomes, the levels of CHC, FL and PCF turn out to be 43.3%, 41.6%, and 29.1% respectively. When combined, the level of PCF and/or FL amounts to 54.2% for the older workers.

Table 2. Background characteristics of older workers (60 years and above), N = 10,746 (34.15%).

Health outcomes: Type of work; Covariates Percentage
Health Outcomes
Chronic Health Conditions: Yes 43.36
Functional Limitations: Yes 41.65
Poor Cognitive Functioning: Yes 29.13
PCF and/or FL: Yes 54.17
Main predictor
Type of work: Informal 73.12
Socio-economic and demographic indicators
Gender: Female 32.41
Age groups: 65+ 45.99
Caste groups
General 21.53
Scheduled Tribe 10.91
Scheduled Caste 21.17
Other Backward Class 46.39
Religion
Hindu 82.83
Muslim 11.10
Others 6.07
Education level
Low 78.17
Middle 16.30
High 5.52
Marital status: Others 25.16
Place of residence: Urban 21.12
Wealth
Low 40.73
Medium 34.92
High 24.35
Household size
1–3 38.14
4–7 47.96
8+ 13.90
Work Characteristics
Working hours
Less than 24 hours 27.49
24–48 hours 42.19
48+ hours 30.31
Duration being in current work
Less than 15 years 19.02
15–30 years 16.92
30–45 years 31.90
45 years and over 32.16
Average wage 5727.70
Life-style Behaviour
Drinking Alcohol: Yes 13.06
Smoking/Consuming Tobacco: Yes 50.87
Physical Activity
Vigorous
Never 42.28
Rare 21.38
Everyday 36.34
Moderate
Never 29.32
Rare 15.09
Everyday 55.59
Yoga/Pranayam
Never 87.60
Rare 4.55
Everyday 7.85
Childhood Health: Poor 2.56
Regions
North 9.14
Central 20.04
East 23.44
Northeast 2.76
West 19.09
South 25.35
Union Territories 0.17

Predominantly, the percentage of older workforce is highest among males, Hindus, OBC group and in rural areas. More than three-fourth of working population belongs to lower education level, while one-third of them lies in low wealth status. Around 64% of older workers have been engaged in labor force for more than 30 years. Further, only 2.6% of older workers had poor health condition during their childhood. Drinking alcohol and smoking/consuming tobacco among older workforce is 13.1 percent and 50.8 percent respectively. Geographically, older workers are more concentrated in South, East, and Central regions of India.

Bivariate analysis results

When health outcomes were examined by type of work, as shown in Fig 2, formal older workers suffer from high burden of CHC as compared to informal counterparts (47.1% vs. 41.9%, p < 0.0001). On the other hand, the risks of FL, PCF, and PCF /and FL are more prevalent among informal workers (FL: 42.5% vs. 39.3%, p < 0.05; PCF: 32.5% vs. 20.0%, p < 0.0001; PCF /and FL: 57.1% vs. 46.3%, p<0.0001).

Fig 2. Level of health outcomes by type of work.

Fig 2

Table 3 presents the estimated rates of sampled older workforce of LASI data by the type of work they engaged in. From the table, it is observed that majority of female workforce are engaged in informal activities, conversely among male population major share lies in formal activities. In context of caste groups, the rate for informal activities is high among SC and ST, while general and OBC holds notable portion in formal activities. The percentage for informal workers is substantial among Muslim and other communities compared to Hindu community. Education and wealth play a significant role in defining nature of work. Low level of financial wellbeing and education reflects high share of work engagement in informal activities. As expected, the level of informal older workers is quite considerable in rural areas, whereas urban areas have a significant share of formal workers. Besides, concentration of informal workers is more in North-East followed by South and Western regions of India. Further, marital status and working hours reflects a meagre difference in determining type of work.

Table 3. Type of work by socio-economic and demographic characteristics.

Covariates Formal (%) Informal (%) Total working population
Gender
Male 29.67 70.33 7,311
Female 21.04 78.96 3,435
Age groups
60–65 26.57 73.43 5,942
65+ 27.23 72.77 4,804
Caste groups
General 32.61 67.39 2,340
Scheduled Tribe 23.83 76.17 2,183
Scheduled Caste 23.45 76.55 1,922
Other Backward Class 26.50 73.50 4,301
Religion
Hindu 27.76 72.24 8,079
Muslim 22.88 77.12 1,036
Others 22.04 77.96 1,631
Education level
Low 22.92 77.08 8,440
Middle 36.10 63.90 1,701
High 55.68 44.32 605
Marital status
Currently married 27.74 72.26 8,168
Others 24.30 75.70 2,578
Place of residence
Rural 24.59 75.41 8,029
Urban 35.40 64.60 2,717
Wealth
Low 22.36 77.64 4,173
Medium 26.51 73.49 3,735
High 34.96 65.04 2,838
Household size
1–3 24.13 75.87 4,098
4–7 25.77 74.23 5,154
8+ 29.79 70.21 1,494
Working hours
Less than 24 hours 27.97 72.03 3,115
24–48 hours 24.76 75.24 4,749
48+ hours 28.83 71.17 2,882
Duration being in current work
Less than 15 years 25.26 74.74 2,007
15–30 years 27.77 72.23 1,786
30–45 years 28.10 71.90 3,366
45 years and over 23.60 76.40 3,394
Regions
North 26.02 73.98 1443
Central 35.73 64.27 1510
East 26.75 73.25 2032
Northeast 18.03 81.97 1464
West 25.87 74.13 1183
South 22.03 77.97 2335
Union Territories 26.45 73.55 779
Total 26.88 73.12 10,746

Chronic health conditions

Table 4 depicts the risk of CHC among older working population in India (crude and adjusted). Informal workers tend to have less odds of CHC compared to formal counterparts. Indeed, their odds are 0.82 folds less (OR = 0.816, 95% CI: 0.748–0.890, p<0.0001). The odds ratios change slightly and remain significant after controlling socio-economic and demographic variables (in Model-2), and other covariates (in Model-3).

Table 4. Odds of multiple logistic regression for CHC.

Covariates Model-1 Model-2 Model-3
Type of work
Formal®
Informal 0.816**** (0.748 0.890) 0.881** (0.801 0.970) 0.891** (0.810 0.981)
Socio-economic & demographic
Gender
Male®
Female 1.174*** (1.061 1.30) 1.098 (0.980 1.231)
Age groups
60–65®
65+ 1.440**** (1.324 1.565) 1.389**** (1.272 1.517)
Caste groups
General®
Scheduled Tribe 0.639**** (0.538 0.758) 0.580**** (0.495 0.679)
Scheduled Caste 0.889 (0.775 1.019) 0.898 (0.783 1.030)
Other Backward Class 0.975 (0.867 1.097) 0.902 (0.806 1.010)
Religion
Hindu®
Muslim 1.221** (1.048 1.423) 1.303**** (1.128 1.506)
Others 1.220** (1.026 1.452) 1.235** (1.064 1.432)
Education level
Low®
Middle 1.213*** (1.075 1.369) 1.144** (1.012 1.293)
High 1.464*** (1.209 1.774) 1.281** (1.049 1.563)
Marital status
Currently married®
Others 1.038 (0.934 1.153) 1.024 (0.921 1.140)
Place of residence
Rural®
Urban 1.863**** (1.671 2.077) 1.679**** (1.508 1.869)
Wealth
Low®
Medium 1.372**** (1.239 1.519) 1.369**** (1.235 1.517)
High 1.732**** (1.533 1.957) 1.711**** (1.518 1.929)
Household size 0.939** (0.896 0.985) 0.942** (0.899 0.987)
Work Characteristics
Working hours
Less than 24 hours®
24–48 hours 0.919** (0.830 1.016)
48+ hours 0.837*** (0.747 0.938)
Ln(Wage) 1.013 (0.964 1.064)
Duration being in current work
Less than 15 years®
15–30 years 0.972 (0.848 1.116)
30–45 years 0.909 (0.805 1.026)
45 years and over 0.895 (0.791 1.013)
Life style behaviour
Drinking Alcohol
No®
Yes 0.928 (0.820 1.049)
Smoking/Consuming Tobacco
No®
Yes 0.996 (0.908 1.092)
Physical Activity
Vigorous
Never®
Rare 0.747**** (0.664 0.840)
Everyday 0.751**** (0.677 0.833)
Moderate
Never®
Rare 1.044 (0.913 1.193)
Everyday 0.943 (0.849 1.047)
Yoga/Pranayam
Never®
Rare 1.223** (1.002 1.492)
Everyday 1.201** (1.038 1.388)
Childhood health
Good/Fair®
Poor 1.694*** (1.306 2.197)
Regions
North®
Central 0.530**** (0.449 0.625)
East 0.896 (0.772 1.040)
Northeast 0.650**** (0.540 0.782)
West 1.162 (0.983 1.374)
South 1.425**** (1.226 1.656)
Union Territories 1.072 (0.880 1.306)
Constant 0.917 0.767 0.553
AIC 14729.10 13912.61 13473.61

Note:

® reference category;

****(P<0.0001),

***(P<0.01),

**(P<0.05), Ln: Natural Log

Additionally, among the many covariates, the model indicates that 65+ age-group is associated with increased risk of CHC. The likelihood of CHC is significantly low among older workers from ST group. On the other hand, this risk expands for Muslim and other religious communities. The odds of CHC significantly inflates with the increase in education and wealth. Similarly, urban workers are having 1.679 times (OR = 1.679, 95%CI: 1.508–1.869, p<0.0001) more odds of CHC than rural older workers. The long working hours is significantly associated with low risk of CHC. Moreover, the physical activities do have significant influence over chronic conditions but with varying directions. Vigorous activities tend to have low risk of CHC, while those who perform Yoga/Pranayam on daily basis have 1.201 times (p<0.05) more odds of chronic conditions. Similarly, poor childhood health is also significantly associated with high risk of CHC. Across India, the likelihood of CHC considerably high in South region, while it is low in Central and North-Eastern regions as compared to North.

Functional limitations

Table 5 exhibits the relationships between FL, CHC residual and type of work, and shows that both CHC residual and type of work are significant risk factors for FL. From Model-1, the odds of FL are 1.110 times more among informal workers in contrast to formal counterparts (p<0.0001) after controlling for CHC residual, while the odds of FL increases by 1.580 times with increase in CHC residual (p<0.0001) after controlling for the type of work. Further, interacting CHC residual with type of work (Model-2 & Model-3) reveals that both type of work and CHC residual maintain their significant level. Indeed, informal workers without CHC residual (CHC residual = 0) have 0.9 times less odds of FL in contrast to formal workers without CHC, adjusted for all the covariates (OR = 0.898, 95% CI: 1.352–1.621, p<0.05). In Model-3, for formal workers, the odds of FL increases by 1.525 (p<0.0001) as one unit increase in CHC residual. Further, the odds of FL for informal workers for per unit increase in CHC residual is 1.512 (OR:1.525*0.992, 95% CI: 1.038–2.205). It shows that, effect of CHC residual is almost similar in both formal as well as informal workers since the differential effect or multiplicative factor (0.992) is close to 1 and non-significant. Meaning that the type of work does not modify the effect of CHC on FL.

Table 5. Odds of multiple logistic regression for FL.

Covariates Model-1 Model-2 Model-3
Res_CHC 1.580**** (1.454 1.717) 1.629**** (1.365 1.944) 1.525**** (1.280 1.817)
Type of work
Formal®
Informal 1.110****(1.013 1.215) 0.896** (0.810 0.992) 0.898** (1.352 1.621)
Type of work*Res_CHC 0.911 (0.743 1.118) 0.992 (0.811 1.214)
Socio-economic & demographic
Gender
Male®
Female 1.786**** (1.611 1.979) 1.968**** (1.756 2.207)
Age groups
60–65
65+ 1.468**** (1.345 1.602) 1.421**** (1.299 1.555)
Caste groups
General®
Scheduled Tribe 1.177 (0.989 1.402) 0.802*** (0.684 0.940)
Scheduled Caste 0.955 (0.826 1.105) 0.891 (0.773 1.028)
Other Backward Class 1.035 (0.912 1.174) 0.928 (0.823 1.046)
Religion
Hindu®
Muslim 1.001 (0.854 1.174) 1.195** (1.030 1.387)
Others 0.944 (0.789 1.131) 0.821** (0.705 0.957)
Education level
Low®
Middle 0.570**** (0.498 0.652) 0.635**** (0.555 0.726)
High 0.431**** (0.342 0.543) 0.512**** (0.406 0.647)
Marital status
Currently married®
Others 1.289**** (1.158 1.434) 1.293**** (1.163 1.438)
Place of residence
Rural®
Urban 0.610**** (0.542 0.687) 0.660**** (0.588 0.740)
Wealth
Low®
Medium 0.795**** (0.715 0.884) 0.798**** (0.719 0.885)
High 0.820**** (0.721 0.932) 0.832*** (0.734 0.943)
Household size 1.043 (0.993 1.096) 1.059** (1.009 1.110)
Work Characteristics
Working hours
Less than 24 hours®
24–48 hours 1.021 (0.922 1.132)
48+ hours 0.949 (0.844 1.066)
Ln(Wage) 0.904*** (0.858 0.952)
Duration being in current work
Less than 15 years®
15–30 years 1.031 (0.894 1.190)
30–45 years 1.003 (0.884 1.137)
45 years and over 1.082 (0.953 1.228)
Life style behaviour
Drinking Alcohol
No®
Yes 1.220*** (1.078 1.380)
Smoking/Consuming Tobacco
No®
Yes 1.256**** (1.142 1.382)
Physical Activity
Vigorous
Never®
Rare 0.957 (0.849 1.079)
Everyday 0.861*** (0.774 0.959)
Moderate
Never®
Rare 1.084 (0.944 1.246)
Everyday 0.937 (0.839 1.046)
Yoga/Pranayam
Never®
Rare 1.103 (0.896 1.357)
Everyday 0.987 (0.845 1.152)
Childhood health
Good/Fair®
Poor 1.361** (1.048 1.767)
Regions
North®
Central 1.027 (0.866 1.218)
East 1.282*** (1.096 1.500)
Northeast 0.869 (0.713 1.057)
West 1.833**** (1.540 2.183)
South 1.969**** (1.682 2.305)
Union Territories 1.263** (1.025 1.556)
Constant 0.566 0.640 0.838
AIC 13737.50 12611.66 12550.70

Note:

® reference category;

****(P<0.0001),

***(P<0.01),

**(P<0.05), Ln: Natural Log

Apart from these key results, among all covariates, it appeared that females are more prone to FL, while educated, wealthy and ST population are less likely to suffer from the same. Further, high odds of FL are common among those who are engaged in unhealthy lifestyle behaviours such as drinking alcohol and consuming tobacco or smoking. Besides, the odds of FL are greater among those who are not currently married (OR: 1.293, p<0.0001) and have poor childhood health (OR: 1.361, p<0.05). Finally, across India, the odds of FL are relatively considerable in Eastern, Western, Southern regions and in Union Territories compared to North.

Poor cognitive functioning

From Table 6, it is observed that the type of work is significantly associated with PCF after controlling for CHC residual (Model-1). Indeed, the odds of PCF (adjusted for type of work) decreases by 0.875 (p<0.01) with one unit increase in CHC residual. Moreover, the odds of PCF (adjusted for CHC residual) are 1.7 folds among informal workers (OR = 1.683, 95%CI: 1.514–1.870, p < 0.0001; compared to formal).

Table 6. Odds of multiple logistic regression for PCF.

Covariates Model-1 Model-2 Model-3
Res_CHC 0.875*** (0.799 0.959) 0.982 (0.785 1.229) 1.000 (0.796 1.257)
Type of work
Formal®
Informal 1.683**** (1.514 1.870) 1.220**** (1.083 1.375) 1.155** (1.152 1.637)
Type of work*Res_CHC 0.965 (0.751 1.240) 0.922 (0.714 1.191)
Socio-economic & demographic
Gender
Male®
Female 2.605**** (2.338 2.902) 2.811**** (2.472 3.195)
Age groups
60–65
65+ 1.478**** (1.338 1.634) 1.370**** (1.232 1.523)
Caste groups
General®
Scheduled Tribe 1.783**** (1.502 2.116) 1.813**** (1.506 2.183)
Scheduled Caste 1.128 (0.954 1.334) 1.128 (0.948 1.341)
Other Backward Class 0.953 (0.822 1.105) 0.939 (0.804 1.096)
Religion
Hindu®
Muslim 0.938 (0.784 1.123) 1.025 (0.850 1.235)
Others (0.800** (0.688 0.930) 0.996 (0.833 1.190)
Education level
Low®
Middle 0.101**** (0.074 0.139) 0.111**** (0.081 0.153)
High 0.066**** (0.031 0.139) 0.080**** (0.037 0.170)
Marital status
Currently married®
Others 1.447**** (1.289 1.624) 1.404**** (1.248 1.581)
Place of residence
Rural®
Urban 0.425**** (0.371 0.487) 0.449**** (0.388 0.520)
Wealth
Low®
Medium 0.549**** (0.490 0.616) 0.551**** (0.489 0.621)
High 0.409**** (0.354 0.473) 0.418**** (0.358 0.488)
Household size 1.093*** (1.037 1.153) 1.096*** (1.038 1.158)
Work Characteristics
Working hours
Less than 24 hours®
24–48 hours 0.799**** (0.709 0.900)
48+ hours 0.826*** (0.720 0.949)
Ln(Wage) 0.824**** (0.775 0.877)
Duration being in current work
Less than 15 years®
15–30 years 1.074 (0.901 1.279)
30–45 years 1.061 (0.910 1.236)
45 years and over 1.283*** (1.106 1.489)
Life style behaviour
Drinking Alcohol
No®
Yes 1.510**** (1.308 1.744)
Smoking/Consuming Tobacco
No®
Yes 0.957 (0.856 1.070)
Physical Activity
Vigorous
Never®
Rare 1.001 (0.869 1.153)
Everyday 0.923 (0.812 1.050)
Moderate
Never®
Rare 0.614**** (0.519 0.726)
Everyday 0.629**** (0.551 0.718)
Yoga/Pranayam
Never®
Rare 0.857 (0.654 1.124)
Everyday 0.729*** (0.593 0.896)
Childhood health
Good/Fair®
Poor 0.616** (0.424 0.893)
Regions
North®
Central 0.835 (0.681 1.024)
East 1.013 (0.838 1.224)
Northeast 0.724*** (0.573 0.914)
West 1.254** (1.016 1.548)
South 1.072 (0.885 1.297)
Union Territories 0.898 (0.695 1.161)
Constant 0.252 0.261 2.217
AIC 12084.2 9878.5 9491.6

Note:

® reference category;

****(P<0.0001),

***(P<0.01),

**(P<0.05), Ln: Natural Log

In Model-3, the odds of PCF are 1.155 times for informal workers without CHC residual (CHC residual = 0) as compared formal workers without CHC residual (OR = 1.155, 95%CI: 1.152–1.637, p<0.05) after controlling for covariates. However, CHC residual loses its significance level after adding the interaction term and controlling socio-economic and demographic variables in model-2, and work-characteristics, life-style behavior, and childhood health in model-3. Moreover, results show that the interaction or differential effect is non-significant, meaning that the effect of CHC residual in both formal and informal workers is quite similar and non-significant.

Among all covariates, a noteworthy gap can be seen among female workers in the odds of PCF when compared to male workers (Model-3). Likewise, the high odds of PCF are significant among ST groups, 65+ cohort and currently not married population as well as those who consume alcohol and working for more than 45 years. The odds of PCF increase as well with the increase in household size. On the other hand, the risk decreases with rise in wealth, educational level, working hours, wage, and movement from rural to urban areas as shown by the estimated odds ratios. Nevertheless, physical activities play important role in improving cognitive function as evident from the odds of moderate exercise and Yoga/Pranayam. Geographically, the risk of PCF is high as indicated by the estimated odds ratio (OR = 1.254, p<0.05) in West region and low (OR = 0.724, p<0.01) in North-Eastern region in comparison to North.

Poor cognitive functioning and/or functional limitations

Table 7 exhibits the relationship between type of work and PCF and/or FL. Result shows that both the type of work and CHC does significantly affect PCF and/or FL in model-1 and model-2. Informal older workers have 1.439 times (p<0.0001) more odds of PCF and/or FL compared to formal older workers. This relationship remains significant after controlling for socio-economic and demographic variables in model-2 but loses its significant level after controlling for lifestyle-behaviour, work characteristics and childhood health in model-3. In case of CHC residual, the odds of PCF and/or FL increase with increase in one unit of CHC residual in model -1. Further, after adding interaction term type of work and CHC residual, the odds of PCF and/or FL among formal older workforce increases with one unit increase in CHC residual (model-2: 1.358, p<0.01; model-3: 1.346, p<0.01). Finally, the interaction term between CHC and type of work is non-significant, and the multiplicative factor estimated through the interaction is close to 1, meaning that the effect of CHC is roughly similar in both formal and informal workers (i.e., no effect modification).

Table 7. Odds of multiple logistic regression for PCF and/or FL.

Covariates Model-1 Model-2 Model-3
Res_CHC 1.249**** (1.152 1.354) 1.358*** (1.138 1.619) 1.346*** (1.125 1.609)
Type of work
Formal®
Informal 1.439**** (1.318 1.572) 1.094** (0.992 1.206) 1.033 (0.934 1.143)
Type of work*Res_CHC 0.986 (0.804 1.208) 0.970 (0.789 1.192)
Socio-economic & demographic
Gender
Male®
Female 2.530**** (2.283 2.805) 2.761**** (2.455 3.105)
Age groups
60–65
65+ 1.530**** (1.403 1.669) 1.435**** (1.309 1.573)
Caste groups
General®
Scheduled Tribe 1.165** (1.003 1.353) 1.200** (1.020 1.410)
Scheduled Caste 0.955 (0.829 1.099) 0.921 (0.797 1.065)
Other Backward Class 0.982 (0.875 1.103) 0.897 (0.794 1.013)
Religion
Hindu®
Muslim 1.056 (0.912 1.223) 1.154** (0.992 1.343)
Others 0.732**** (0.640 0.838) 0.854** (0.732 0.995)
Education level
Low®
Middle 0.404**** (0.355 0.459) 0.434**** (0.380 0.495)
High 0.334**** (0.267 0.418) 0.384**** (0.304 0.484)
Marital status
Currently married®
Others 1.419**** (1.272 1.582) 1.378**** (1.233 1.541)
Place of residence
Rural®
Urban 0.530**** (0.477 0.588) 0.545**** (0.485 0.611)
Wealth
Low®
Medium 0.643**** (0.581 0.713) 0.638**** (0.574 0.709)
High 0.564**** (0.500 0.635) 0.586**** (0.516 0.665)
Household size 1.047** (0.997 1.098) 1.077*** (1.025 1.132)
Work Characteristics
Working hours
Less than 24 hours®
24–48 hours 0.904** (0.814 1.004)
48+ hours 0.898 (0.798 1.011)
Ln(Wage) 0.864**** (0.820 0.911)
Duration being in current work
Less than 15 years®
15–30 years 0.978 (0.847 1.130)
30–45 years 0.916 (0.807 1.040)
45 years and over 1.125 (0.989 1.280)
Life style behaviour
Drinking Alcohol
No®
Yes 1.444**** (1.275 1.635)
Smoking/Consuming Tobacco
No®
Yes 1.094 (0.994 1.204)
Physical Activity
Vigorous
Never®
Rare 1.000 (0.795 1.054)
Everyday 0.865*** (0.776 0.965)
Moderate
Never®
Rare 0.915 (0.795 1.054)
Everyday 0.809**** (0.724 0.905)
Yoga/Pranayam
Never®
Rare 1.021 (0.828 1.258)
Everyday 0.952 (0.816 1.111)
Childhood health
Good/Fair®
Poor 1.106 (0.843 1.451)
Regions
North®
Central 0.969 (0.818 1.147)
East 1.335**** (1.141 1.562)
Northeast 0.878 (0.725 1.065)
West 1.563**** (1.307 1.869)
South 1.754**** (1.496 2.057)
Union Territories 1.058 (0.857 1.306)
Constant 0.801 0.927 2.992
AIC 14391.0 12691.9 12482.6

Note:

® reference category;

****(P<0.0001),

***(P<0.01),

**(P<0.05), Ln: Natural Log

Apart from these key results, among all covariates, it appeared that females are more prone to PCF and/or FL, while educated and wealthy are less likely to suffer from the same. Further, high odds of FL are common among those who are engaged in unhealthy lifestyle behaviours such as drinking alcohol, but health lifestyle such as rigorous or moderate physical activity reduces the risk of PCF and/or FL. Besides, the odds of PCF and/or FL are 1.378 (p<0.0001) times greater among those who are not currently married. Finally, across India, the odds of PCF and/or FL are relatively considerable in Eastern, Southern and Western regions compared to North.

Sensitivity analyses

Sensitivity analyses have also been performed by gender, place of residence and age-groups, focussing on the association between the type of work and each of the four health outcomes. Tables of results are attached as supplementary materials. The summary of the main results is given below:

  1. For CHC—the effect of type of work is significant only in male (S1 Table in S1 Appendix) and 60–65 age group (S3 Table in S1 Appendix) with formal workers having higher odds of CHC.

  2. For FL—the type of work, without CHC residual (CHC residual = 0), exhibit significant effects on FL (less odds of FL for informal compared to formal workers) within females (S4 Table in S1 Appendix) and 65 + age group (S6 Table in S1 Appendix) only. Moreover, the effect of CHC is much stronger among informal male workers (OR = 1.585) than female workers (OR = 1.412), and even much stronger among informal urban workers (OR = 1.857) than rural workers (OR = 1.449), while within age groups, the effect is much stronger among formal 60–65 aged workers (OR = 1.667) than 65+ aged workers (OR = 1.340) (S4 to S6 Tables in S1 Appendix).

  3. For PCF—informal workers exhibit higher odds of PCF within both male and female, rural and urban areas, and age groups. However, the effects of type of work are significant only within male (S7 Table in S1 Appendix), rural area (S8 Table in S1 Appendix) and 65+ age group (S9 Table in S1 Appendix) workers.

  4. For PCF and/or FL—The effect of CHC is significant within male and female, although slightly stronger among informal male workers (OR = 1.370) than formal male workers (OR = 1.334) (S10 Table in S1 Appendix). Moreover, the effect of CHC is also significant within 60–65 age group only, but much stronger among formal workers (OR = 1.452) than informal workers (OR = 1.365) (S12 Table in S1 Appendix). Finally, the effect of CHC is also significant within both rural and urban residence areas, but much stronger among urban workers (informal: OR = 1.653; formal: OR = 1.449) (S11 Table in S1 Appendix).

Discussion

In the backdrop of increasing older population in India and the paucity of pension/ financial benefits schemes, it is quite likely that this population is still working after the retirement age. The present study supports this argument and observed that around one-third of the population aged 60 years and above are still in labour force. However, majority of this population are engaged in informal activities contributing nearly 73 percent of total older population.

Besides, the share of labour force participation is higher among males than that of females. On the other hand, the participation rate of female population in informal activities is greater compared to male counterparts. Certainly, females are generally expected to spend most of the time in household activities and taking care of their family members. Consequently, they choose low paid elementary activities which needs less work time [2, 20, 51, 52]. Likewise, the engagement in informal work is highest among Muslim community, Scheduled Caste, and Scheduled Tribe groups. It is well documented that these sections of the society in India are marginalized due to their poor socio-economic conditions. Reddy (2016) explains that socio-economically disadvantage populations tend to have high labour-force participation rate in later ages. Further, pronounced level of participation in informal sector can be observed among older population with low education and wealth. This large workforce is mostly engaged in agricultural activities, casual labour or unskilled occupations which require less education [2, 20]. Generally, agricultural activities in India are concentrated in rural areas and involve subsistence farming, resulting in high proportion of workforce participation in later life.

Previous studies demonstrated that work engagement has a pronounced effect on physical and mental health. Consistent with these articles, the present research reaffirms that work engagement does play a significant role in determining unfavourable health outcomes. Nevertheless, current findings also provide the evidence of varied unfavourable health outcomes by type of economic activity which has not been documented in former research. In fact, informal older workers are less likely to suffer from CHC and FL, while more likely to have PCF as compared to formal older workers. The emergence of high CHC rates is most likely to be observed among educated and wealthy groups [22, 25, 76] which is closely attributed to socio-economic profiles of formal workers. Nonetheless, noticeable change in nature of relationship is observed between type of work and FL. In model-1, the risk of FL is substantially high among informal workers, but after controlling for the covariates in model-3, the risk of FL changed drastically reflecting favourable effect of informal activities on FL for older people with no chronic health conditions. The low risk of FL among informal workers confirms healthy work effect concept suggested by former literatures [48, 52, 57, 77] because informal activities involve physically demanding works and only those can be engaged in later life who are not suffering from severe physical functioning.

Continuous work engagement in later life may have leading implication on cognitive functioning [11, 48, 50, 51]. Extending from this relationship, the present research also illustrates varied influence of type of work on PCF. For instance, informal workers without any CHC are more likely to suffer from PCF as compared to formal workers without CHC. Likewise, the combined health conditions such as PCF and/or FL are relatively high among informal workers after adjusting for CHC. However, this relationship is not significant after controlling for work-characteristics, lifestyle behaviour and childhood health conditions. The major factor which distorts the relationship between type of work and PCF and/or FL is unhealthy lifestyle behaviour such as drinking alcohol. Further, the risk of PCF and/or FL increases among formal workers with increase in CHC and remains consistent after controlling for all the covariates. From this finding, it can be inferred that unhealthy lifestyle may lead to serious health implication in later life of older workers especially among formal sector workers with CHC.

From the sensitivity analysis results, it can be observed that the risk of CHC is significantly low among informal male and 60–65 age group workers. Moreover, FL is less prevalent among informal female and 65+ age group workers. Conversely, the risk of PCF is relatively high among informal male, rural areas, and 65+ age group working population. The reason of low functional limitations among informal females and 65+ age group workers compared to their formal counterparts is an example of “healthy work effect” [48, 52, 57, 77], which means female and 65+ age group informal workers are already in better physical condition to continue their economic activity.

Further, this study has certain limitations such as use of cross-sectional data at a single point of time. Thus, result of the study could only provide the evidence of statistical association between type of work and health outcomes not the cause-effect relationship. To get the better picture of type of work and health, longitudinal data would be a better option. Thus, future studies based on cause-effect relationship between type of work and health outcomes would provide a platform for preventive strategies to deal with health-related issues of working older population.

Conclusion

Older population in India constitutes an undeniable share of labour-force after the retirement age of 60 years. This extent is the outcome of financial constraints caused by paucity in social and health insurance schemes. Moreover, working longer impacts physical and mental health of the older people which varies by formal or informal sector of employment. Further, improving health conditions of this vulnerable population should be an utmost priority for policy makers to encourage active and healthy ageing.

Therefore, the present study underscores the relevance of policies focusing on providing health and healthcare benefits by respective economic activity and socio-economic position. Further, policies should also put emphasis on promotion of healthy lifestyle behaviour among older workers. Adequate working conditions should be considered during policy formulation, which can offer a level of job satisfaction and contribute to better well-being. Moreover, the preference of employment type should be given precedence according to the age-groups. It would be better that older adults aged 70+ should participate in part-time jobs as they may be unsuitable to handle high strain and physically demanding work. Economic security policy should be recommended to those who are lacking physical capacity. This can help them to sustain their livelihood without any financial constraints. Additionally, campaigns should be promoted by the government and other social bodies to create awareness regarding benefits physical activity and drawbacks of consuming alcohol on mental and physical health in later life. The issues of older workers in India should be taken seriously otherwise it will lead to a huge chunk of vulnerable groups with inadequate social and financial support.

Supporting information

S1 Appendix

(DOCX)

Acknowledgments

I humbly thank International Institute for Population Sciences (IIPS) for giving me access to Longitudinal Ageing Study of India dataset for this research.

Ethical approval

This research was performed in compliance with all applicable laws and institutional guidelines. Ethical approval was obtained from the University of Canberra’s Human Research Ethics Committee (reference number: 202211511).

Data Availability

The data underlying this study are third party and were collected by the Longitudinal Ageing Study in India (2017-18). Raw survey data have been accessed from International Institute for Population Sciences website, and the data request form has been downloaded from the following link: https://www.iipsindia.ac.in/content/LASI-data. Then, the duly signed form has been sent to the email "datacenter@iipsindia.ac.in" for approval. The principal coordinator of LASI data is Prof. T. V. Sekher (email: tvsekher@iipsindia.ac.in). The authors confirm that others would be able to access the data in the same manner and that the authors did not have any special access privileges that others would not have.

Funding Statement

The author(s) received no specific funding for this work.

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Decision Letter 0

Simona Lorena Comi

15 Jun 2022

PONE-D-22-08253Informal Sector Employment and the Health Outcomes of Older Workers in IndiaPLOS ONE

Dear Dr. Chowdhury,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

The referees and I see value in this paper, given the novelty that it brings to the literature on how working after retirement can affect individual health, which, and I do agree with the referees on this point, is a very interesting and important topic.  Given the clear expertise of the referees, I defer to their comments and will ask you to simply respond to them. However, my view is that the main areas of concerns, which you would do well to address in rewriting the paper, are as follows:

  1. I agree with the reviewers that the main drawback of the current version of the paper it is that your empirical strategy does not take into account self-selection of individuals. Even though you are looking for associations and not to causal relationships - and this should be made clear in the paper and the language used should be adapted accordingly- I believe that the issues raised by the referees, i.e. self-selection and reverse causality- should be discussed, and documented as much as possible together with potential biases suffered by your coefficients, as suggested by reviewer 2. In particular, I agree with reviewer 1 that control functions could provide a viable and helpful solutions to control for self-selection and should be used in the baseline estimates. These estimates could be added as a robustness exercise should it turn out that the estimates do not change when controlling for self-selection. For more details, please refer to the comments of the Reviewers reported below.

  2. I believe that controlling for initial conditions in health, as suggested by reviewer 1, will provide another useful robustness exercise. You should discuss the problems your identification strategy suffers due to the lack of longitudinal data, and provide evidence of how robust are your results to the inclusion of initial conditions.

  3. Finally, separate estimates by gender will effectively acknowledge differences existing in the selection process related to gender and clustering will provide more reliable standard errors, as suggested by reviewer 2.

Beyond the above highlighted points, as I noted previously the referee reports are all of high quality, so please make sure to respond directly to all the comments.

Congratulations on the work so far; I look forward to reading the revision.

Please submit your revised manuscript by Jul 30 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

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Academic Editor

PLOS ONE

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Reviewers' comments:

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Comments to the Author

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Reviewer #1: Yes

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

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Reviewer #1: No

Reviewer #2: No

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Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Review of the paper “Informal Sector Employment and the Health Outcomes of Older Workers in India.”

General Comment

The paper focuses on an important research question: how does working after retirement age in the formal and informal sector expose older people to health events. The topic is crucial in the context of India, where a large proportion of the population is not covered by social security and bears on a family network to live at older ages.

The paper takes advantage of the LASI survey and evaluates the association between working in the formal and informal sector after age 60 and health outcomes. The main results suggest that individuals in the informal sectors have higher chances of poor cognitive functioning, whereas working in the formal sector is associated with more chronic health conditions and functional limitations. The study calls for policy able to protect older workers by providing health healthcare benefits.

I think this paper brings a good perspective on an important policy question and takes advantage of both survey data and econometric techniques to address this question. However, the fact that these results are only an association between the field of work and health events, thus causality cannot be claimed, makes the findings relatively weak and could not provide sufficient ground for a robust empirical analysis. I leave to the editor the decision whether the paper, after major revisions, is sufficiently original to be considered for publication.

Major Points to be addressed.

As a general comment, I think the authors should address the role of selection in their analysis: those who work over the retirement age are usually either at the top or bottom of the income distribution for different reasons. In particular, those who are at the bottom of the income distribution indeed are those who need to work to make their ends meet. In this context, if the sample includes primarily individuals working in the informal/formal sector belonging to the bottom of the income distribution, I suspect the role of selection: since health status is correlated with socioeconomic conditions, you are looking at people with lower health capital and attributing to them an effect of working longer on their health status, which is instead due to an initial lower health endowment. Thus, you are looking at selected individuals who are likely to have poor health status in general.

Another important question which has not been addressed is the reverse association (given that we cannot claim causality) between the type of work and health conditions. What if individuals with cognitive deficits, limitations in functioning (and chronic diseases) are more likely to find a job in the informal (or formal) sector and work after age 60 (to make their ends meet)? Thus, if this is the case, then it could be that having pre-existing health conditions predicts the chance of working in certain types of jobs, which is associated with higher chances of having these health conditions lately.

Overall, I think that the paper should clarify from the beginning that this study looks at the association between formal/informal sectors and health outcomes, and it is not claiming causality.

Pg 5 of the manuscript: “However, no study till date, nationally or internationally, has emphasised this aspect (concerning the extent to which the health conditions are associated with the type of employment for older workers). I argue that the following reference looks at this type of association, which is not cited in the paper.

Nag, A., Vyas, H., & Nag, P. (2016). Occupational health scenario of Indian informal sector. Industrial health, 2015-0112.

Although they do not specifically focus on the older workers, their sample includes a vast population of workers. Thus, I think that this study should be acknowledged at least.

Page 6: in Figure 1, I think another critical piece of information to be taken into account is the initial health endowment: following the seminal contribution of Grossman (1972), health is part of the human capital of each individual; thus, the initial health endowment should be taken into account when evaluating the effect of the type of work on late-life health effects.

For example, the authors should consider including health as a child. To avoid the omitted variable bias problem, I advise the author to include the information about the childhood health conditions available in the LASI questionnaire on questions HT231, HT232, HT233 HT234. This information is much needed to be considered to control for the initial health endowment.

Page 7: There is a reference to the total sample of the survey, but how many individuals are aged above 60? The text-only reports those who are still in the workforce.

Section 2. (page 8) Functional Limitations: there is no reference to which ones are the 13 specific activities

Type of work section (page 9): there is no reference to the complete list of classification of occupation nor in the appendix. Al least an example should be provided to allow the reader to get a grasp of the classification.

Methods (page 7 onwards): Although this study looks at the association between type of work and health outcomes using logistic regression models, I wonder why the authors did not provide alternative models such as probabilistic or ols models. In this context, I also argue that the choice of measuring CHC as a function of the polynomial in Model-3 would suggest the need to instrument this variable. Thus, when looking at FL and PCF outcomes, including the CHC as control could be done by exploiting the Control Function approach à la Wooldridge (2015), thus instrumenting the CHC with residuals of Model-3 in Table-1.

Finally, are the results reported in Tables 4 to 6 coefficients or marginal effects? To compare results across Tables, marginal effects should be displayed to have a sense of the magnitude.

Table-2: The sample composition is not gender-balanced. This might have affected the results. I also wonder whether the place of residence, which is proportioned toward the rural area, has again some drawbacks such as self-selection of those individuals who are poorer and less educated (in line with the 78% of individuals in the sample reporting low education level).

The role of household size appears to be particularly important in Indian society. I would suggest the author show the distribution of household size greater than 4, given that it includes 61.34% of the sample.

Bivariate analysis results (page 13): I suggest adding the confidence intervals to Figure 2.

Tables from 4 (page 15): as a general comment, I wonder why doing yoga could increase the chances of CHC and how the authors explain this finding.

As a general comment, I would suggest the authors conduct sensitivity analyses by subgroups of individuals, namely by gender, geographical area, and age group 60-64 and 65+. This could confirm the robustness of the results.

Another alternative classification related to formal vs informal jobs is the separation between non-strenuous vs strenuous jobs. This could be investigated as an alternative.

Minor Points to be addressed

Page 3: When reporting “India, …., reportedly 8.6 percent (104 million) of the total population in 2011…” I think a reference should be added.

Page 6: Why there is the name of the authors reported next to reference number (7)? I think that the manuscript should show consistency with the style of referencing.

References

Nag, A., Vyas, H., & Nag, P. (2016). Occupational health scenario of Indian informal sector. Industrial health, 2015-0112.

Wooldridge (2015), Control function methods in applied econometrics, Journal of Human Resources, 50(2), 420-445.

Reviewer #2: This paper uses the baseline wave of longitudinal Ageing Study in India (LASI) to investigate the association between health and employment in later years, as well as the heterogeneous effect by employment type. The analytical sample contains only working populations over age 60. Overall, the paper is well written in a clear and scientific matter. Empirical results consistently show the health effect varies by employment type and specific health outcomes. Employment type significantly moderates the effect of CHC on FL, and FL on PCF.

Comments:

My major comments are on the complexity of employment in later years as established by existing research (e.g., Rietveld et al.,2014; van Zon et al.,2020). It is understandable that the cross-sectional nature of the dataset limits further exploration of any dynamic aspects of employment, also, the goal of the paper is not aimed at a causal identification. However, it could be more informative to add some relevant descriptive statistics, sensitivity checks, or comments regarding the defined employment status that might not truly reflect the general associations.

1) The observed employment type might contain some noise due to potential complex work transitions in later years such as partial retirement. Some transitions and jobs could be quite recent and temporary, especially in the informal sector, which may require additional control for working characteristics such as working years and sectors (public/private).

Without any further details, it is possible that some people are working as a recovery from an early retirement or mandatory retirement, or at a phase of bridge job. For one thing, the current employment can differ much from their main career which determinants one’s pension and other welfare schemes.

For another, the health effect of employment might be biased given potentially complex sorting into employment for older workers. For instance, if one transited from a full-time office-based job to self-employment to better manage working hours, the estimated health effect of the informal sector might vary by time. Socioeconomically advantaged individuals might extend working life as a way to continue social participation which probably exerts a positive impact on mental health and well-being, in the meanwhile, affecting physical health.

2) It would be better to add separate estimation by gender considering the gender difference in terms of both health, healthcare utilisation and employment aspects (e.g., Kandrack et al.,1991). Especially, labour force participation is more selective among females than males, and there are also great heterogeneities across occupations within formal or informal sectors. For instance, continued employment may buffer against risk factors that aggravate women’s cognitive health (Oi, Katsuya 2019).

For other minor comments:

3) It might be better to cluster standard error at a household level to account for the potential correlation among employment/retirement decisions within a household. Old couples might have a joint retirement (or working) plan.

4) The implication about the healthcare services needs could probably be better supported by adding some descriptive statistics about healthcare utilisation, and healthcare entitlements (if data permits).

5) Potential measurement error due to cognitive impairment. To what extent the estimated might be affected by the recall error in covariates such as wealth and job characteristics? Any potential screening criteria for cognitive impairment? Are surveyed people all self-interviewed or include proxy answers?

Typos:

P17: informal workers without CHC have 0.8 folds less odds

P26: those determinants which have considerable impacts

Reference:

1) Kandrack, Mary-Anne, Karen R. Grant, and Alexander Segall. "Gender differences in health related behaviour: some unanswered questions." Social science & medicine 32.5 (1991): 579-590.

2) Oi, Katsuya. "Does gender differentiate the effects of retirement on cognitive health?." Research on Aging 41.6 (2019): 575-601.

3) Rietveld, Cornelius A., Hans van Kippersluis, and A. Roy Thurik. "Self‐employment and health: Barriers or benefits?." Health economics 24.10 (2015): 1302-1313.

4) van Zon, Sander KR, et al. "Multimorbidity and the transition out of full-time paid employment: a longitudinal analysis of the health and retirement study." The Journals of Gerontology: Series B 75.3 (2020): 705-715.

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Attachment

Submitted filename: PLoS report_20220530.docx

PLoS One. 2023 Feb 22;18(2):e0266576. doi: 10.1371/journal.pone.0266576.r002

Author response to Decision Letter 0


30 Aug 2022

We would like to thank the reviewers for their useful comments. Please consider our responses below. Please note that all references to line numbers in this response letter relate to line numbers in the document with track changes.

Reviewer reports:

Reviewer 1:

Major Points to be addressed:

Reviewer 1 - Comment#1: As a general comment, I think the authors should address the role of selection in their analysis: those who work over the retirement age are usually either at the top or bottom of the income distribution for different reasons. In particular, those who are at the bottom of the income distribution indeed are those who need to work to make their ends meet. In this context, if the sample includes primarily individuals working in the informal/formal sector belonging to the bottom of the income distribution, I suspect the role of selection: since health status is correlated with socioeconomic conditions, you are looking at people with lower health capital and attributing to them an effect of working longer on their health status, which is instead due to an initial lower health endowment. Thus, you are looking at selected individuals who are likely to have poor health status in general.

Another important question which has not been addressed is the reverse association (given that we cannot claim causality) between the type of work and health conditions. What if individuals with cognitive deficits, limitations in functioning (and chronic diseases) are more likely to find a job in the informal (or formal) sector and work after age 60 (to make their ends meet)? Thus, if this is the case, then it could be that having pre-existing health conditions predicts the chance of working in certain types of jobs, which is associated with higher chances of having these health conditions lately.

Overall, I think that the paper should clarify from the beginning that this study looks at the association between formal/informal sectors and health outcomes, and it is not claiming causality.

Reply: We thank the reviewer for this useful comment.

We agree with the reviewer on the comments regarding the potential issues of selection and reverse-causation. We believe that addressing these issues will improve the overall presentation of this manuscript. First, we acknowledge the reviewer’s suggestion to clarify from the beginning that this study looks at the association between formal/informal sectors and health outcomes (page 5, lines 12-19). Based on reviewer’s comments, we also have done some modifications in our analysis (page 10, lines 12, 22-24; page 11, lines 21-25).

Studies elsewhere found that prolonged working beyond retirement age influences health conditions of the older population. In that context little has been explored on working life and its influence on the health outcomes of Indians in older age. In this study we analysed how type of formal/informal sector employment among older people (60 years and more) influences their health outcomes. While in India older population suffers from poor health conditions irrespective of their socio-economic status, few studies have focused on the sector of employment in this age group and how it influences their health. We agree with the reviewer’s concern on individuals self-selecting themselves into the formal/informal nature of employment based on their pre-existing health conditions. Meaning that there may be two-way relationship where the pre-existing health conditions influencing the type of employment and vice versa. However, this research is about how the prolonged working of older people beyond their retirement age in the formal/informal sector of employment influences their health outcomes. We believe that it is unlikely for individuals to self-selecting into the type of employment due to their pre-existing health status. We agree with the reviewer’s observation that older adults from low socio-economic status continue working if their financial circumstances do not permit them to retire. Those who are higher up in the socio-economic status and do not want to give up earning or those who are passionate about their work may continue working as well. We believe that, while individuals may potentially self-select into informal/formal sector of employment in their young working age, they do not continue to do so at an older age. Although the study sample is skewed towards low education level (78%), it does not include primarily the bottom of the income distribution (low level of wealth) which represents 40.7%, compared to 34.9% and 24.4% in medium and high wealth levels, respectively. Also, the sample information on how long people have been working in their present occupation reveals that, on average, they have been in their present occupation for 36 years, rather than choosing the sector of employment and/or shifting jobs at an older age. Moreover, formal and informal sector work types in India encapsulate a broad range of occupations and, while individuals might select the type of occupation (within the formal or informal sector) due to their pre-existing health status, it is unlikely that they will select between formal and informal sector activities. Having said that, we do not deny the fact that some people with greater physical and cognitive impairment may self-select into one of these sectors from the very beginning of their work life and not at an older age. We assume that would be a minority in our sample. Therefore, we believe that working beyond retirement age due to financial limitations and the nature of work (formal/informal) could influence older people’s health conditions which is the focus of this research.

We are aware of the potential bias due reverse association, as we are limited to use cross-sectional data in the absence of longitudinal data. However, we believe that the use of covariates’ adjustment in the multivariable regression models performed will alleviate both self-selection and reverse association induced bias. Additionally, we have addressed and discussed these issues in the study limitation section (pages 35, lines 15 to 19).

Reviewer 1 - Comment#2: Pg 5 of the manuscript: “However, no study till date, nationally or internationally, has emphasised this aspect (concerning the extent to which the health conditions are associated with the type of employment for older workers). I argue that the following reference looks at this type of association, which is not cited in the paper.

Nag, A., Vyas, H., & Nag, P. (2016). Occupational health scenario of Indian informal sector. Industrial health, 2015-0112.

Although they do not specifically focus on the older workers, their sample includes a vast population of workers. Thus, I think that this study should be acknowledged at least.

Reply: Thank you for the suggestion.

The paper by Nag et al. (2016) has discussed about occupational hazards and injuries of selected cases of the informal sector. Based on their finding, they have advocated for protective measurement to safeguard the workers from the harsh work environment. This paper is not directly related with our study because we are focusing on long term health conditions. However, we have cited this paper in our discussion section as some of its finding can provide support to our arguments (page 33, line 15; page 34, line 1).

Reviewer 1- Comment#3: Page 6: in Figure 1, I think another critical piece of information to be taken into account is the initial health endowment: following the seminal contribution of Grossman (1972), health is part of the human capital of each individual; thus, the initial health endowment should be taken into account when evaluating the effect of the type of work on late-life health effects.

For example, the authors should consider including health as a child. To avoid the omitted variable bias problem, I advise the author to include the information about the childhood health conditions available in the LASI questionnaire on questions HT231, HT232, HT233 HT234. This information is much needed to be considered to control for the initial health endowment.

Reply: Thank you for the suggestion.

To avoid the omitted variable bias problem, we have incorporated childhood health conditions and the duration of current work in the study as covariates to control for. This is seen in the abstract (page 2, line 9), materials and methods (page 10, lines 12, 22-24) and in Tables 4-7.

Reviewer 1 - Comment#4: Page 7: There is a reference to the total sample of the survey, but how many individuals are aged above 60? The text-only reports those who are still in the workforce.

Section 2. (page 8) Functional Limitations: there is no reference to which ones are the 13 specific activities

Type of work section (page 9): there is no reference to the complete list of classification of occupation nor in the appendix. Al least an example should be provided to allow the reader to get a grasp of the classification.

Reply: Thank you for the comment.

We have added number of older individuals 60 years and above in data source section (page 8, line 7). We have added tables describing functional limitations (table S14) and type of work (table S13) in the appendix section.

Reviewer 1 - Comment#5: Methods (page 7 onwards): Although this study looks at the association between type of work and health outcomes using logistic regression models, I wonder why the authors did not provide alternative models such as probabilistic or ols models. In this context, I also argue that the choice of measuring CHC as a function of the polynomial in Model-3 would suggest the need to instrument this variable. Thus, when looking at FL and PCF outcomes, including the CHC as control could be done by exploiting the Control Function approach à la Wooldridge (2015), thus instrumenting the CHC with residuals of Model-3 in Table-1.

Finally, are the results reported in Tables 4 to 6 coefficients or marginal effects? To compare results across Tables, marginal effects should be displayed to have a sense of the magnitude.

Reply: Thank you for the comments and suggestions.

The reviewer is correct. Alternative models such as probabilistic (probit/tobit) or OLS models can also be used for the analysis. However, in our analysis we wanted to compare those workers who had poor health outcome by their type of economic activity. For example, for cognitive functioning we have compared only those who have poor cognitive level to understand if person is likely to experience PCF, how the risk of PCF varies by type of work. For this purpose, we have constructed our variable in binary form (presence vs. absence) and used logistic regression model.

We thank the reviewer for the suggestion regarding CHC residual, it really helped in improving the results of our analysis. We have incorporated CHC residual as a control variable in all our models for Functional Limitations and Poor Cognitive Functioning, instead of using the actual values for CHC (as shown in Table 5, 6 and 7, pages 20-26). The reviewer’s comment also prompted us to consider a new outcome variable which combines both poor cognitive functioning and functional limitations (PCF and/or FL) (page 8, line 19 and page 9, lines 22-24). The new variable is motivated in the research framework section (page 6, lines 23-25, page 7, lines 1-8). The following text has been added into the manuscript.

Page 6, lines 23-25 - However, the functional limitations and poor cognitive functioning are closely related to each other, as evident from previous studies that physical disabilities or functional limitations increases the risk of poor cognitive functioning in older persons.

Page 7, lines 1-8 - Rajan, Hebert (2013), Chodosh, Miller‐Martinez (2010) elaborates that functional limitation plays a key in amplifying the risk of cognitive decline through neurodegenerative processes. Likewise, poor cognitive is associated with high likelihood aggregated functional limitations (66-68). McGuire, Ford (2006) mentioned that older people with lower level of cognitive are more likely to become physically disabled than those with high cognition. Based on the findings of these studies, the combine variable of poor cognitive functioning and/or functional limitation is constructed to provide a better relationship between type of work, physical and cognitive functioning.

Page 9, lines 22-24 – The PCF and/or FL variable is constructed by combining Poor Cognitive functioning and Functional limitation health outcomes. Below is description of PCF and/or FL:

PCF_FL= {█(1, if PCF=1 and/or FL=1@0, otherwise)┤

Results of PCF and/or FL is given below (page 26, lines 2-15; page 27, lines 1-8):

Table-7 exhibits the relationship between type of work and PCF and/or FL. Result shows that both the type of work and CHC does significantly affect PCF and/or FL in model-1 and model-2. Informal older workers have 1.439 times (p<0.0001) more odds of PCF and/or FL compared to formal older workers. This relationship remains significant after controlling for socio-economic and demographic variables in model-2 but loses its significant level after controlling for lifestyle-behaviour, work characteristics and childhood health in model-3. In case of CHC residual, the odds of PCF and/or FL increase with increase in one unit of CHC residual in model -1. Further, after adding interaction term type of work and CHC residual, the odds of PCF and/or FL among formal older workforce increases with one unit increase in CHC residual (model-2: 1.358, p<0.01; model-3: 1.346, p<0.01). Finally, the interaction term between CHC and type of work is non-significant, and the multiplicative factor estimated through the interaction is close to 1, meaning that the effect of CHC is roughly similar in both formal and informal workers (i.e., no effect modification).

Apart from these key results, among all covariates, it appeared that females are more prone to PCF and/or FL, while educated and wealthy are less likely to suffer from the same. Further, high odds of FL are common among those who are engaged in unhealthy lifestyle behaviours such as drinking alcohol, but health lifestyle such as rigorous or moderate physical activity reduces the risk of PCF and/or FL. Besides, the odds of PCF and/or FL are 1.378 (p<0.0001) times greater among those who are not currently married. Finally, across India, the odds of PCF and/or FL are relatively considerable in Eastern, Southern and Western regions compared to North.

Thank you for suggesting marginal effects to display the magnitude of effect of each co-variable, other covariates being held constant. But as far as we believe, odds ratio can also be used to present magnitude of effects of the covariates, like marginal effects do. With the logistic regression approach, we are modelling the risk or probability of the event (e.g., risk or probability of experiencing PCF). The choice of odds ratios is automatic as we are comparing the odds of PCF in formal and informal groups. Regression coefficients are at the log-scale; by taking their exponentiation, we reverse back to the odds scale.

Reviewer 1 - Comment#6: Table-2: The sample composition is not gender-balanced. This might have affected the results. I also wonder whether the place of residence, which is proportioned toward the rural area, has again some drawbacks such as self-selection of those individuals who are poorer and less educated (in line with the 78% of individuals in the sample reporting low education level).

The role of household size appears to be particularly important in Indian society. I would suggest the author show the distribution of household size greater than 4, given that it includes 61.34% of the sample.

Reply: Thank you for the comment.

We have cross-checked our result through sensitivity analysis by gender, place of residence and age groups. A section on sensitivity analysis is added in the manuscript (page 29, lines 3-23; page 30, lines 1-3).

The figure below shows the distribution of household size greater than 4. The highest of percentage of household size is concentrated between 4 to 8 members of the household. However, we re categorized the household size variable into three categories namely 1. 1-3 members, 2. 4-7 members, 3. 8+ members.

Reviewer 1 - Comment#7: Bivariate analysis results (page 13): I suggest adding the confidence intervals to Figure 2.

Reply: We thank the reviewer for this useful comment. The confidence intervals have now been added in the figure 2.

Reviewer 1 - Comment#8: Tables from 4 (page 15): as a general comment, I wonder why doing yoga could increase the chances of CHC and how the authors explain this finding.

Reply: Thank you for the comment.

Thank you for pointing out this result. The increase in CHC using Yoga is an interesting result because we are using cross-sectional data and can only justify association. So, it could be possible that, those people who are performing yoga, are more likely to be suffering from any chronic health conditions.

Reviewer 1 - Comment#9: As a general comment, I would suggest the authors conduct sensitivity analyses by subgroups of individuals, namely by gender, geographical area, and age group 60-64 and 65+. This could confirm the robustness of the results.

Another alternative classification related to formal vs informal jobs is the separation between non-strenuous vs strenuous jobs. This could be investigated as an alternative.

Reply: We thank the reviewer for this insightful comment. We believe that addressing this comment in the revised draft will improve the clarity of the results.

As mentioned in the previous comment (comment #6), the sensitivity analyses have been performed by gender, geographical area, and age groups.

The sensitivity analysis has confirmed the robustness of our result, which is described below (page29-30):

For CHC - the effect of type of work is significant only in male (Table S1) and 60-65 age group (Table S3) with formal workers having higher odds of CHC.

For FL - the type of work, without CHC residual (CHC residual=0), exhibit significant effects on FL (less odds of FL for informal compared to formal workers) within females (Table S4) and 65 + age group (Table S6) only. Moreover, the effect of CHC is much stronger among informal male workers (OR=1.585) than female workers (OR=1.412), and even much stronger among informal urban workers (OR=1.857) than rural workers (OR=1.449), while within age groups, the effect is much stronger among formal 60-65 aged workers (OR=1.667) than 65+ aged workers (OR=1.340) (Tables S4 to S6).

For PCF - informal workers exhibit higher odds of PCF within both male and female, rural and urban areas, and age groups. However, the effects of type of work are significant only within male (Table S7), rural area (Table S8) and 65+ age group (Table S9) workers.

For PCF and/or FL - The effect of CHC is significant within male and female, although slightly stronger among informal male workers (OR=1.370) than formal male workers (OR=1.334) (Table S10). Moreover, the effect of CHC is also significant within 60-65 age group only, but much stronger among formal workers (OR=1.452) than informal workers (OR=1.365) (Table S12). Finally, the effect of CHC is also significant within both rural and urban residence areas, but much stronger among urban workers (informal: OR=1.653; formal: OR=1.449) (Tables S11).

Thank you for suggesting an alternative classification for the type of work, which we believe would provide a different insight on the association between the type of work and health outcome. This suggestion can be examined for our future research because analysis based on non-strenuous vs strenuous job classification in the present paper would deviate from our study objective which focuses on the classification based on two major economic activities.

Minor Points to be addressed:

Reviewer 1 - Comment#10: Page 3: When reporting “India, …., reportedly 8.6 percent (104 million) of the total population in 2011…” I think a reference should be added.

Page 6: Why there is the name of the authors reported next to reference number (7)? I think that the manuscript should show consistency with the style of referencing.

Reply: Thank you for the comment.

Reference has been added in this statement.

All the referencing errors have been corrected.

Reviewer 2:

Reviewer 2 - Comment#1: My major comments are on the complexity of employment in later years as established by existing research (e.g., Rietveld et al.,2014; van Zon et al.,2020). It is understandable that the cross-sectional nature of the dataset limits further exploration of any dynamic aspects of employment, also, the goal of the paper is not aimed at a causal identification. However, it could be more informative to add some relevant descriptive statistics, sensitivity checks, or comments regarding the defined employment status that might not truly reflect the general associations.

1) The observed employment type might contain some noise due to potential complex work transitions in later years such as partial retirement. Some transitions and jobs could be quite recent and temporary, especially in the informal sector, which may require additional control for working characteristics such as working years and sectors (public/private).

Without any further details, it is possible that some people are working as a recovery from an early retirement or mandatory retirement, or at a phase of bridge job. For one thing, the current employment can differ much from their main career which determinants one’s pension and other welfare schemes.

For another, the health effect of employment might be biased given potentially complex sorting into employment for older workers. For instance, if one transited from a full-time office-based job to self-employment to better manage working hours, the estimated health effect of the informal sector might vary by time. Socioeconomically advantaged individuals might extend working life as a way to continue social participation which probably exerts a positive impact on mental health and well-being, in the meanwhile, affecting physical health.

Reply: We thank the reviewer for this insightful comment.

We agree with reviewer that past work characteristics and job transition are important indicators that could have been useful in our analysis, however LASI data does not provide information pertaining to past jobs. Further, as per the Indian context, the phenomena of job transition are quite unlikely, especially a shift from formal to informal sector are not common. As per our analysis, 64% of the sample participants spent 30 years or more in their current job activity, and on average, people spent 36 years in their present job. For older population (age of 60 years and above), these statistics indicate low level of job transition. Moreover, in LASI data, public/private sector related information is only applicable for few selected formal sectors (service or salaried person).

Without any further details, it is possible that some people are working as a recovery from an early retirement or mandatory retirement, or at a phase of bridge job. For one thing, the current employment can differ much from their main career which determinants one’s pension and other welfare schemes. We agree with the reviewer that the current employment can differ much from the main career. This might be the case for the 19% of sample participants whose duration in the current work is less than 15 years. However, in the Indian context, it is less likely that these people would be working as a recovery from retirement or a phase of bridge job. We have now cross-checked our results through sensitivity analysis by gender, age-group, and place of residence. We believe this added value to the overall presentation of the manuscript and improved clarity of our findings. We have now added this information in the appendix section from table S1-S12. From the sensitivity analysis we have found that the risk of CHC is significantly low among informal male and 60-65 age group workers. Moreover, FL is less prevalent among informal female and 65+ age group workers. Conversely, the risk of PCF is relatively high among informal male, rural areas, and 65+ age group working population.

Reviewer 2 - Comment#2: It would be better to add separate estimation by gender considering the gender difference in terms of both health, healthcare utilisation and employment aspects (e.g., Kandrack et al.,1991). Especially, labour force participation is more selective among females than males, and there are also great heterogeneities across occupations within formal or informal sectors. For instance, continued employment may buffer against risk factors that aggravate women’s cognitive health (Oi, Katsuya 2019).

Reply: Thank you for the comment.

We thank the reviewer and agree that gender specific analysis will add value to this research. We have now conducted separate gender specific analysis. Please refer to our response to your Comment#1 and Reviewer-1’s comment#9. While the objective of this research is to study the association between type of work and health outcomes. We will study, healthcare utilization by type of work in the next research objective (as part of PhD thesis) which will be covered in a different paper.

For other minor comments:

Reviewer 2 - Comment#3: It might be better to cluster standard error at a household level to account for the potential correlation among employment/retirement decisions within a household. Old couples might have a joint retirement (or working) plan.

Reply: Thank you for the comment. While we agree with the reviewer’s concern about cluster standard error at household level as it might be affecting the consistency of the coefficient estimates. However, we believe that might not be a major issue in this study as around 80% (from LASI data) of the respondents in our sample are single working members from a household.

Reviewer 2 - Comment#4: The implication about the healthcare services needs could probably be better supported by adding some descriptive statistics about healthcare utilisation, and healthcare entitlements (if data permits).

Reply: Thank you for the comment.

We agree with the reviewer’s concerns on health service utilisation, and we are addressing that in another study as part of the PhD thesis.

Reviewer 2 - Comment#5: Potential measurement error due to cognitive impairment. To what extent the estimated might be affected by the recall error in covariates such as wealth and job characteristics? Any potential screening criteria for cognitive impairment? Are surveyed people all self-interviewed or include proxy answers?

Reply: Thank you for the comment.

In LASI, the Health and Retirement study (HRS) module has been used to derive cognitive measures. These measures are collected using various domains- including memory, orientation, retrieval fluency (verbal fluency), arithmetic, executive functioning, and object naming. To measure the cognitive functioning, the respondents were asked certain questions pertaining to the cognitive measure domains and the responses were noted by interviewer based on the feedback or reply from the respondents, so no proxy person was involved during the interview. Further, as per the LASI report, those participants were excluded from the measurement who sought or receive assistance during interview.

Reviewer 2 - - Comment#6: Typos:

P17: informal workers without CHC have 0.8 folds less odds

P26: those determinants which have considerable impacts

Reply: Thank you for the comment.

All the typo errors have been rectified in the manuscript.

Attachment

Submitted filename: Response_to_Reviewer.docx

Decision Letter 1

Simona Lorena Comi

11 Oct 2022

PONE-D-22-08253R1Informal Sector Employment and the Health Outcomes of Older Workers in IndiaPLOS ONE

Dear Dr. Chowdhury,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Thank you for submitting the revised version of your manuscript to PLOS ONE. Both reviewers and I feel that the paper is much improved. However, there are a few issues raised by the reviewers that you should address. I would like you to revise your paper, taking into account the comments of the referees (see below).

Specifically, I do agree with Reviewer 1 that self-selection into job could be an issue and should be mentioned and discussed in the paper. Furthermore, the Discussion section is not very effective and should be shortened and rewritten to better highlight your key results.

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Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

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Reviewer #1: Yes

Reviewer #2: Yes

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Reviewer #2: Yes

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Reviewer #1: No

Reviewer #2: No

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

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Reviewer #1: Yes

Reviewer #2: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: I think the authors have responded satisfactorily to most of the comments from the first review round. I do however still have some small comments for some of them.

In particular, I think the role of individuals with poor health self-selecting into poorer jobs, which leads to a stronger deterioration of health should be acknowledged better than as it is now in the manuscript. Although it is unlikely that individuals self-selected themselves into the type of employment due to pre-existing health status later in life, it could be that they self-select at the beginning of their working careers and they remain in poor jobs.

It is fundamental to stress that individuals could ex ante engage in poor jobs due to their precarious health status at a young age and thus leading to late-life health decline. I think this point could be better explained in the introduction, as they explain in the report which I received.

Finally, regarding the Discussion session, I found the section very dense and I would suggest stressing the key findings of the paper as well as the take-home message, in order to provide a more synthetic interpretation.

Minor Comments

Table 2 : I wonder whether for binary covariates it would be sufficient to report only one category (for example only those who have chronic health conditions, instead of both no/yes), to make the tables more compact.

Reviewer #2: Many thanks for your efforts in the revision, and I think all my concerns have been responded or addressed properly.

For the new version, I might have two additional comments. The first is the control function approach which has changed many models. If I understand correctly, it is used as a control for partial chronic conditions that are unexplained by observables. If much of variation in chronic conditions have been explained in a separate model, the residual variable might not be a good proxy for chronic conditions.

Second, I am not sure whether I grasp the idea of combining PCF and FL as the fourth outcome variable to explore the potential interactions between PCF and FL. Indeed, in the final results, the coefficients of informal worker on PCF and FL have opposite signs, making the coefficient on PCF/PF insignificant. I am not sure about the idea here or the relevant explanation.

**********

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Reviewer #2: No

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PLoS One. 2023 Feb 22;18(2):e0266576. doi: 10.1371/journal.pone.0266576.r004

Author response to Decision Letter 1


15 Nov 2022

We would like to thank the reviewers for their useful comments. Please consider our responses below. Please note that all references to line numbers in this response letter relate to line numbers in the document with track changes.

Reviewer reports:

Reviewer 1- Comment#1: I think the authors have responded satisfactorily to most of the comments from the first review round. I do however still have some small comments for some of them. In particular, I think the role of individuals with poor health self-selecting into poorer jobs, which leads to a stronger deterioration of health should be acknowledged better than as it is now in the manuscript. Although it is unlikely that individuals self-selected themselves into the type of employment due to pre-existing health status later in life, it could be that they self-select at the beginning of their working careers and they remain in poor jobs. It is fundamental to stress that individuals could ex ante engage in poor jobs due to their precarious health status at a young age and thus leading to late-life health decline. I think this point could be better explained in the introduction, as they explain in the report which I received.

Reply: We thank the reviewer for this useful comment.

As per the reviewer’s suggestion, we have added some lines on “self-section into job” in the research framework section of manuscript (page no. 6 and line no. 13-21).

The paragraph is as follows:

“However, the relationship between type of work and health could also be affected by self-selection bias in which a person may self-select into the type of work due to pre-existing health conditions, even from younger age. Meaning that there may be two-way relationship where the pre-existing health conditions influencing the type of employment and vice versa. In the case of India, the self-section into poor jobs is implausible because formal and informal sector types of work encapsulate a broad range of occupations. While individuals might select the type of occupation (within the formal or informal sector) due to their pre-existing health status, it is unlikely that they will select between formal and informal sector activities and continue to do so at an older age.”

Reviewer 1- Comment#2: Finally, regarding the Discussion session, I found the section very dense and I would suggest stressing the key findings of the paper as well as the take-home message, in order to provide a more synthetic interpretation.

Reply: Thank you for pointing this out, we have improved our discussion section by focusing only on the key findings of the paper, and we have also removed some paragraphs which were not that important. Further, discussion section is segregated in 5 aspects: 1. basic scenario of older workers in India, 2. association between type of work and health outcomes, 3. role of other covariates, 4. sensitivity analysis, and 5. study limitations.

Following paragraphs, we have removed from the discussion section:

1. From page no. 29, line 10-17

Consequently, agrarian households tend to have larger family size which is assumed to provide better manpower to support farming activities. This can be clearly seen through current findings showing higher work participation for larger family size households. However, it is also important to note that the level of engagement in informal activities is considerable for those households with small family sizes. Tafuro (2020) elucidated that intergenerational support is strongly related with son’s preference in countries like, India, China, Vietnam, and South Korea, and it is quite common that older people without sons are more likely to be economically active in these regions.

2. Page 31 (line 24-25) and page 32 (line 1-2)

It is because Japan is a developed country where provision for social and financial security is strong, therefore older workers only engage to maintain their social network and get the sense of pride of being economically independent.

3. Page no. 32, line 13-19

Heterogeneity in context of health outcomes across regions can be clearly observed in India. Notably, chances of CHC upsurges in southern region, but FL is relatively intensifying in southern and western region. Geographically, there is a stark difference in terms of PCF, it rises in western region, then dwindles in north-eastern region. Further, the combine conditions of PCF and/or FL are high in eastern, western, and southern regions of India. Despite of physical and mental health limitations, older population in India are still working after the retirement age especially in informal sector.

Reviewer 1- minor comment#1: Table 2: I wonder whether for binary covariates it would be sufficient to report only one category (for example only those who have chronic health conditions, instead of both no/yes), to make the tables more compact.

Reply: Thank you for the suggestion.

Now, we have reported only the percentage of health outcomes variables, and other binary covariates in Table-2 (page no.13).

Reviewer 2- Comment#1: Many thanks for your efforts in the revision, and I think all my concerns have been responded or addressed properly.

For the new version, I might have two additional comments. The first is the control function approach which has changed many models. If I understand correctly, it is used as a control for partial chronic conditions that are unexplained by observables. If much of variation in chronic conditions have been explained in a separate model, the residual variable might not be a good proxy for chronic conditions.

Reply: Yes, CHC residual is the unexplained partial chronic conditions which we have calculated through the following procedure:

1. We have run the full model for CHC incorporating all the covariates (Table-4, model-3).

2. Then, the predicted value of CHC is calculated.

3. Further, the residual value is calculated by subtracting predicted CHC from the observed CHC.

So, the reviewer’s understanding is correct, if most of the variation is explained in chronic conditions, taking residual variable of chronic condition should not be a good proxy. However, in our case, the CHC residual in Table-5, Table-6, and Table-7 for model-1 is coming significant, which means that there are still some unexplained variations in CHC which is also influencing our outcome variables. Therefore, we could say that taking CHC residual as a proxy for CHC is a better option. Moreover, the use of the control function was suggested by the first reviewer in the first review round. Indeed, the reviewer #1 stated: “Thus, when looking at FL and PCF outcomes, including the CHC as control could be done by exploiting the Control Function approach à la Wooldridge (2015), thus instrumenting the CHC with residuals of Model-3 in Table-1”.

Reviewer 2- Comment#2: Second, I am not sure whether I grasp the idea of combining PCF and FL as the fourth outcome variable to explore the potential interactions between PCF and FL. Indeed, in the final results, the coefficients of informal worker on PCF and FL have opposite signs, making the coefficient on PCF/PF insignificant. I am not sure about the idea here or the relevant explanation.

Reply: Thank you for the comment.

The rationale behind combining PCF and/or FL is constructed to search for a better and stronger relationship between type of work, physical and cognitive functioning. Further, previous literatures have emphasised that PCF and FL are the two-sides of the same coin because functional limitation plays a key in amplifying the risk of cognitive decline (Miller Martinez et al., 2010; Rajan et al., 2013), whereas poor cognitive is associated with high likelihood of functional limitations (McConnell et al., 2002; Dodge et al., 2005; McGuire et al., 2006).

The coefficients of informal worker on FL, PCF, and PCF/FL (main effects, Model 1 in Tables 5, 6 & 7) have all positive signs and are statistically significant. The opposite signs for coefficients of informal worker on PCF and FL in the final model results should not be interpreted as the main effects since these models include the interaction term type of work * residual CHC. These coefficients represent the effect of type of work in the absence of any residual CHC (i.e., residual CHC = 0). Moreover, the final models have been adjusted for various covariates, some being enough important to explain some of the variation in FL, PCF, and PCF/FL. The insignificant result of type of work on PCF and/or FL may not necessarily due to the opposite signs but to other covariates controlled for in the model. It may suggest as well that the type of work could not have any influence if a person suffers from both the conditions. Further, other unhealthy life-style behaviours may play an important role in distorting the relationship between type of work and PCF and/or FL. The rationale of PCF and/or FL and reason for insignificant relationship between type of work and PCF and/or FL is already mentioned in research framework section (page no. 7 and line no. 5-15) and discussion section (page no. 30 and line no. 14-17).

Research framework (page no. 7 and line no. 5-15):

However, the functional limitations and poor cognitive functioning are closely related to each other, as evident from previous studies which reported that physical disabilities or functional limitations increase the risk of poor cognitive functioning in older persons. Indeed, Rajan, Hebert (2013), Chodosh, Miller‐Martinez (2010) elaborates that functional limitation plays a key in amplifying the risk of cognitive decline through neurodegenerative processes. Likewise, poor cognitive is associated with high likelihood aggregated functional limitations [66-68]. McGuire, Ford (2006) mentioned that older people with lower level of cognitive are more likely to become physically disabled than those with high cognition. Based on the findings of these studies, the combined variable of poor cognitive functioning and/or functional limitation is constructed to search for a stronger relationship between type of work, physical and cognitive functioning.

Discussion (page no. 30 and line no. 14-17):

However, this relationship is not significant after controlling for work-characteristics, lifestyle behaviour and childhood health conditions. The major factor which distorts the relationship between type of work and PCF and/or FL is unhealthy lifestyle behaviour namely such as drinking alcohol.

Attachment

Submitted filename: Reviewers reply_final.docx

Decision Letter 2

Simona Lorena Comi

26 Dec 2022

PONE-D-22-08253R2Informal Sector Employment and the Health Outcomes of Older Workers in IndiaPLOS ONE

Dear Dr. Chowdhury,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

My apologies for the time it has taken me to get back to you despite a very timely response from the two original reviewers. Both reviewers are overall quite happy with the progress made but reviewer 1 still wants to see a few additional changes to the discussion section before recommending an unconditional acceptance. I agree with that assessment – you have responded very well to most of the issues raised and as a result, the manuscript has taken a big step toward a final publication. However, I would still ask you to address the remaining comments of reviewer 1 in a final revision of your paper.

Please submit your revised manuscript by Feb 09 2023 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

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PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: No

Reviewer #2: No

**********

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PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The authors have addressed all my comments. However, I want to stress that the discussion needs some adjustments. The discussion should focus on the main findings and the paper's strength and limitations, as well as potential future research. As it is now the discussion includes also the basic scenario (which is well explained in the introduction) and the role of covariates (which I do not find essential in this section). I think the authors could improve the discussion. After that, the paper would likely be ready to be accepted for publication.

Reviewer #2: Many thanks for the updated version. All my comments have been explained in general. My small concern will still be around the justification to combine CPF and FL although they are closely and positively correlated. For me, the separate results for each as outcome variable seem to be already informative about the effect of informal sector on health outcomes. The mechanisms might be different for cognition and functional limitation.

**********

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Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

**********

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PLoS One. 2023 Feb 22;18(2):e0266576. doi: 10.1371/journal.pone.0266576.r006

Author response to Decision Letter 2


23 Jan 2023

We would like to thank the reviewers for their useful comments. Please consider our responses below.

Reviewer reports:

Reviewer 1:

The authors have addressed all my comments. However, I want to stress that the discussion needs some adjustments. The discussion should focus on the main findings and the paper's strength and limitations, as well as potential future research. As it is now the discussion includes also the basic scenario (which is well explained in the introduction) and the role of covariates (which I do not find essential in this section). I think the authors could improve the discussion. After that, the paper would likely be ready to be accepted for publication.

Reply: We thank the reviewer for this useful comment. As per the suggestion of the reviewer, we have removed the points pertaining to roles of covariates from the discussion as the interpretation of other covariates is already given in result section. Following are the points which we have removed from page no. 30 (lines 8-25) to 31 (lines 1-21).

“This research also sheds light on those determinants of unfavourable health outcomes which are socio-economic and demographic attributes, work characteristics, lifestyle behaviour, childhood health and regions of India. Among them, prolonged work engagement has detrimental effect on physical and cognitive functioning for those who are female older workers if likened to male counterparts. Commonly mainstream female workers are employed in informal activities, and they alone work as domestic workers giving rise to double burden of activities [51, 52, 78]. Additionally, it is known that women live longer than men and continue to work in their later life with one or more disabilities [11, 52, 79]. Increasing age has adverse implications on health conditions of older people [22, 80, 81], which can be observed through the result that 65+ working population tend to suffer more from physical and mental health conditions. In Indian society, ST and Muslim community are also the part of vulnerable and marginalized sections who tend to work longer in later ages. The risk of PCF is substantial among ST groups, while the burden of CHC is more prominent among Muslim community. This is may be because ST group is mostly engaged in manual labour or scavenging [82], and agricultural labour activities [83] which is associated with decline in cognitive ability [51]. On the other hand, Muslim community in India are well known for their engagement in informal artisanal work such as weaving, carpentry, black-smithing, and Zari work which is related ergonomic condition leading to CHC [78, 84-87]. However, the combination of PCF and/or FL is remarkably high among both ST group and Muslim community which reflects having these poor conditions altogether elevates the health risk for any marginalized community as compared to their well-off counterparts.

Education and wealth are considerable predictors of unfavourable health outcomes. Increase in education and wealth leads to reduction in FL, PCF, and PCF and/or FL, though escalating the chances of CHC. As evident from studies that better education and wealth improves the physical functioning and work ability [44, 45]. In case of work characteristics, increase in working hours and wages is associated with improvement in PCF, but this result is contradictory to the studies conducted in Japan which states that part time or low working hours improves the cognitive functioning of older workers [10, 11]. Although as it is cross-sectional study, the results could also reflect that only those older people are working longer who have better cognitive functioning. The life-style behaviours are essential components which needs to be taken into account to justify the relationship between type of work and health. Drinking alcohol and consuming tobacco/ smoking can lead to serious health implication, as evident from the result that it degrades physical as well as cognitive functioning. Subsequently, vigorous physical exercise diminishes the risk of CHC and FL, however Yoga/ Pranayam ameliorates cognitive functioning. Moreover, adverse impacts of CHC and FL can be minimized by staying active and maintaining a healthy lifestyle [88-90]. On the other hand, poor childhood health condition worsens the risk of CHC, and FL. Similar findings can be seen in the findings of Pavela and Latham (2016), White, Campo (2013) that poor childhood conditions are strongly associated with development of chronic conditions in later ages.”

Moreover, we have added few lines related to potential future research in page no.32 and line no. 8 to 11.

“Thus, future studies based on cause-effect relationship between type of work and health outcomes would provide a platform for preventive strategies to deal with health-related issues of working older population.”

Reviewer 2:

Many thanks for the updated version. All my comments have been explained in general. My small concern will still be around the justification to combine PCF and FL although they are closely and positively correlated. For me, the separate results for each as outcome variable seem to be already informative about the effect of informal sector on health outcomes. The mechanisms might be different for cognition and functional limitation.

Reply: Thank you for pointing out your concern pertaining to combined variable of PCF and FL. Our rationale of PCF and/or FL is based on the previous literatures which have emphasised that PCF and FL are the two-sides of a same coin as both are related to each other. Further, we were also interested to see the influence of type of work if a person is having both the health conditions. Indeed, separate analysis have provided the informative findings, but we have also found that type of work does not play a significant when a person suffers from both the conditions. In other words, having PCF and FL together could diminishes the influence of type of work.

Attachment

Submitted filename: response_to_reviewer_3rd.docx

Decision Letter 3

Simona Lorena Comi

7 Feb 2023

Informal Sector Employment and the Health Outcomes of Older Workers in India

PONE-D-22-08253R3

Dear Dr. Chowdhury,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Simona Lorena Comi

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: No

Reviewer #2: No

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The authors have addressed my concerns regarding the discussion part and I think that the manuscript is now in good shape.

Reviewer #2: Many thanks for further explanation. According to the coefficients from previous Tables, the correlation between working sector and FL and PCF work in an opposite direction - reducing the significance level and the size of the coefficient in Table 7. The findings from separate regressions do suggest more interesting and probably complex relationship between PCF and FL, as well as working sector. As the results do not suggest causal effect, it seems that people working in an informal sector, like agriculture, are likely to have greater physical capacity, which in the meanwhile offsets some cognition declining. The results in this part might need more explanations. The results seem to suggest weaker relevance to the point as suggested by the literature, like any potential amplification of one problem to the other. Since this does not affect the main conclusion and results in general, I am fine with the current version

**********

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Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

**********

Acceptance letter

Simona Lorena Comi

10 Feb 2023

PONE-D-22-08253R3

Informal Sector Employment and the Health Outcomes of Older Workers in India

Dear Dr. Chowdhury:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

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on behalf of

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Academic Editor

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Associated Data

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    Supplementary Materials

    S1 Appendix

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    Attachment

    Submitted filename: PLoS report_20220530.docx

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    Submitted filename: Response_to_Reviewer.docx

    Attachment

    Submitted filename: Reviewers reply_final.docx

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    Submitted filename: response_to_reviewer_3rd.docx

    Data Availability Statement

    The data underlying this study are third party and were collected by the Longitudinal Ageing Study in India (2017-18). Raw survey data have been accessed from International Institute for Population Sciences website, and the data request form has been downloaded from the following link: https://www.iipsindia.ac.in/content/LASI-data. Then, the duly signed form has been sent to the email "datacenter@iipsindia.ac.in" for approval. The principal coordinator of LASI data is Prof. T. V. Sekher (email: tvsekher@iipsindia.ac.in). The authors confirm that others would be able to access the data in the same manner and that the authors did not have any special access privileges that others would not have.


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