Association of frailty and disability in community dwelling older adults: a cross sectional study

Abstract

Frailty is one of the independent predictors of disability. There is a large shift in the Kingdom of Saudi Arabia toward improving health care system due to the increasing older adult population. Limited research has explained the relationship between frailty status and disability in Saudi older adults. Therefore, the aim of the current study was to investigate the relationship between physical frailty and disability using a cross-sectional design study. A total of 324 participants aged 50 years or older were recruited in the study; participants diagnosed with dementia, Alzheimer’s, or severe cognitive or physical impairment were excluded from the study. All participants underwent a physical examination procedure and completed structured questionnaires. Frailty status was determined using the FRAIL scale. Disability was categorized using the Activities of Daily Living scale. Samples were categorized based on frailty status (Frail, Pre-frail, and No-Frail) using the FRAIL scale. The sample’s mean age was 65.7 years, with females (71.7%) having a higher prevalence of disability than males (28.4%). Participants with two or more chronic conditions had a higher prevalence of disability (62.4%). The fully adjusted model shows that pre-frail (OR: 2.62; 95% CI [1.44, 4.97], p = 0.002) and frail (OR: 4.05; 95% CI [1.69, 9.65], p = 0.002) groups were significantly associated with having disability compared to robust group after adjustments for age, sex, BMI, and number of chronic conditions. This study provided a foundation for disability projects in Saudi Arabia to promote the understanding of the underlying mechanisms of the relationship between frailty and disability for the Saudi community.

Introduction

Saudi Arabia is going through a demographic change, with an increasing number of older adults. The older adult population is expected to increase from 9.5% of the overall population in 2035 to 18% by 2050¹. This demographic shift will place a significant burden on the healthcare system, as it will lead to an increased prevalence of age-related health issues, including physical frailty and disability. There is a large shift in the Kingdom of Saudi Arabia toward improving the healthcare system due to the increasing older adult population. The improvements in the healthcare system included accessibility to healthcare, prevention strategies, screening for chronic conditions, and early interventions to manage chronic conditions, especially for older adults. Frailty is a significant concern, with recent estimates placing its prevalence at approximately 21% among older Saudi adults¹². In addition, our previous work has found that the prevalence of chronic diseases increases with older age, including diabetes, hypertension, frailty, osteoarthritis, and physical inactivity^2–6. Therefore, studying the conditions related to older adults and factors related to independence is of interest to help in screening and managing chronic conditions such as frailty.

Physical frailty is described as a multidimensional syndrome characterized by decreased physiological reserve and increased vulnerability to external stressors⁷. Frailty often leads to a variety of adverse health outcomes, including disability, falls, hospitalization, loss of independence, and mortality⁸.

Fried Phenotype measured frailty through five physical criteria, including weight loss; weakness or poor handgrip strength; exhaustion, slow walking speed; and low physical activity⁹. From a different perspective, Rockwood & Mitnitski in 2001, suggested a Cumulative Deficit Model as a quantitative measure of frailty index¹⁰. The Cumulative Deficit Model defines frailty as the accumulation of health deficiencies, including chronic medical conditions, cognitive impairment, abnormal laboratory values, and dependence in ADLs¹⁰. They conducted a survival analysis over a 5-year cohort and concluded that frailty index can predict the survival probability. The overlapping between frailty, comorbidity and disability has been described by Fried et al., 2004⁹. Both frailty and comorbidity independently predict the development of disability, while disability can worsen frailty and comorbidities. in addition, comorbid diseases may contribute to the development of frailty. In Saudi Arabia, a recent review by Alshanberi (2023) explored frailty in the Saudi context and its association with concomitant diseases, such as diabetes mellitus, highlighting that frailty and these concomitant conditions are associated with higher rates of mortality and disability among older adults¹¹. Furthermore, a cross-sectional study by Alqahtani et al. 2021 showed that the high prevalence of frailty was associated with age, multimorbidity, and cognitive impairment¹².

Considering the overlap between comorbidities and frailty, the prevalence of comorbidities in the Saudi population is significantly high among both older and younger age groups^2,3,13,14. Another factor is that the age group of 50 years and older has a retirement option in general in Saudi Arabia. However, previous literature on the association between frailty and disability has primarily focused on adults aged 65 years and above¹⁵. Therefore, it is crucial to explore frailty and disability in both older and younger populations to identify associated factors and develop preventive and therapeutic strategies to mitigate frailty and limit its effects.

The current study seeks to fill this gap by investigating the relationship between frailty and disability. This study will enhance the understanding of the association between frailty and disability in the Saudi population and guide the clinical practice in establishing public healthcare policies to mitigate the effects of frailty.

Methods

Study design and participants

A cross-sectional correlational study was conducted in Saudi Arabia to examine the relationship between physical frailty and disability in community-dwelling adults. Data collection occurred from March to June 2023, utilizing diverse community locations such as malls, mosques, and social gathering venues for participant recruitment in the Riyadh region. Ten qualified physiotherapy researchers gathered data at a university clinic, which included demographic and clinical variables such as age, gender, body mass index (BMI), and chronic health conditions. Disability was assessed using basic activities of daily living (ADLs). Participants had to be at least 50 years old, capable of reading and writing in Arabic. Participants diagnosed with dementia, Alzheimer’s, or severe cognitive impairment were excluded from the study. The decision to include individuals starting at age 50 was informed by national statistics indicating a 3% prevalence of disability among Saudi adults younger than 60¹⁶.

All methods were carried out in accordance with the Declaration of Helsinki. Informed consent was obtained from all subjects and/or their legal guardian(s). The Research Ethics Committee of Prince Sattam bin Abdulaziz University granted approval for this study on March 1, 2022 (No. RHPT/022/010).

Sample size calculation

The sample has been calculated based on previous evidence related to the prevalence of disability in Saudi Arabia³². The reported prevalence of disability was 3.3%. Therefore, we calculated the sample size using this formula [N = Z² P(1-P)/d²]. Where N = sample size, Z = Z score statistic for a level of confidence (1.96), P = the prevalence of disability, and d = the degree of precision (0.05). The sample size was estimated to be 318. Therefore, we recruited 324 participants using a convenient sample.

Demographics and clinical variables

The study gathered data on sociodemographic, and self-reported diagnoses of significant comorbidities, including hypertension, diabetes, cardiovascular disease, lung disease, and neurological diseases, cancer, arthritis, depression, kidney disease, and low back pain, and osteoporosis A list of chronic health issues was provided to determine the total count of chronic (i.t., continuous variable) health issues for covariate analysis. In addition to the continuous variable, the number of chronic conditions was classified into three categories: none, one chronic condition, and two or more chronic conditions.

Outcome measures

Disability was measured using the Arabic version of the basic ADL scale^17,18. The Arabic version of the basic ADL scale comprises six items designed to evaluate overall functional performance in domains such as bathing, dressing, toileting, transferring (mobility), continence, and feeding. This instrument has established validity and reliability within an older adults Arabic population residing in nursing homes. Each component is scored with values of 0, 0.5, or 1, leading to a cumulative ADL score ranging from 0 to 6. A score of 0 indicates complete dependence, scores from 1 to 5 denote varying degrees of partial dependence, and a score of 6 represents full independence. The final scores are then multiplied by 100 to facilitate conversion^17,19. Further, Participants were categorized having disability when scored less than 100 on ADL scale and not having disability when they scored 100 on ADL scale^20–22. The Arabic version of the ADL scale showed high validity and reliability in middle and older age groups¹⁷.

The Arabic version of the FRAIL scale is a 5-domain tool for assessing physical frailty²³. The five domains are: resistance, fatigue, illnesses, ambulation, and loss of weight. Scores on the scale range from 0 to 5, with 0 being the best state and 5 representing the worst. A score of 3 to 5 implies frailty, 1 to 2 suggests pre-frailty, and 0 indicates robust.

• Resistance: Respondents are asked if they had any difficulty walking up 10 steps by themselves without resting and without assistance. A response of “yes” is scored as 1 point.

• Fatigue: Subjects are asked if they feel exhausted in the last 4 weeks. A response of “all of the time” or “most of the time” is scored as 1 point.

• Illness: Subjects are asked to report their chronic conditions. A score of 1 is given for subjects who report 5 or more chronic conditions out of 11 total illnesses.

• Ambulation: Subjects are questioned about the difficulties of walking several hundred meters on their own and without assistance. “Yes” replies are scored one point.

• Loss of weight: Participants are asked if they have lost 5% or more of their body weight in the last year. A response of “yes” is scored as 1 point.

• The overall score for the FRAIL scale is determined by aggregating the scores from each of the five domains.

A cumulative score of 3 to 5 is indicative of frailty, whereas a score between 1 and 2 suggests pre-frailty, and a score of 0 denotes robust health or the absence of frailty. Furthermore, the Arabic version of the FRAIL scale shows satisfactory internal consistency, robust test-retest reliability, and strong validity²⁴.

Data analysis

Data analysis was conducted using an analytic software called Stata version 15.1 (Company information: Stata Corp, College Station, TX). For continuous sociodemographic variables, means and standard deviations were reported, while percentages were used for categorical variables. An independent t-test was employed to compare baseline characteristics across disability status groups with respect to continuous variables, and a chi-square test was utilized for categorical variables. To investigate the relationship between frailty groups—considered as an associated factor (independent variable)—and disability status—defined as the outcome variable (dependent variable)—a binary logistic regression model was constructed, with the robust group serving as the reference category. Two models were developed: one unadjusted and the other adjusted for age, sex, BMI, and the number of chronic conditions. Odds ratios (OR) along with 95% confidence intervals were reported, and statistical significance was established at α ≤ 0.05.

Results

A total of 324 participants were included in the present study. Table 1 presents the participants’ basic demographic and clinical information. The mean age of our sample was 65.7 ± 7.2 years, with ages ranging from 50 to 92 years. Participants with any kind of disability were older (68 ± 8 years) than participants without disability (64 ± 6.9 years). Female participants had a higher prevalence of disability (71.7%) than male participants (28.4%). Participants with two or more chronic conditions had a higher prevalence of disability (62.4%). Pre-frail participants had a higher prevalence of disability (55%) than robust and frail participants. There were significant differences between disability status in age, sex, BMI, frailty status, and number of chronic conditions (P<0.05).

Table 1.

Presents the sociodemographic and clinical characteristics of the study sample based on their disability status.

Variables	Total sample	No disability n = 215	Disability	p*
	n = 324		n = 109
Age, mean (SD)	65.7 (7.2)	64 (6.9)	68 (8.0)	< 0.001
Sex, n (%)				0.003
Male	131 (40.4)	100 (46.5)	31 (28.4)
Female	193 (59.6)	115 (53.5)	78 (71.7)
Marital satus, n (%)				< 0.001
Divorced	18 (5.5)	11 (5.1)	7 (6.4)
Married	228 (70.4)	167(77.6)	61 (55.9)
Widowed	78 (24.1)	37(17.2)	41 (37.6)
BMI (Kg/m2), mean (SD)	28.6 (5.6)	27.8 (4.84)	30.2 (6.64)	0.001
Number of chronic conditions				0.004
None	72 (22.6)	54 (25.1)	18 (16.5)
1	92 (28.4)	69 (32.1)	23 (21.1)
2 or more	160 (49.4)	92 (42.8)	68 (62.4)
Frailty status				< 0.001
Frail	43 (13.3)	18 (8.4)	25 (22.9)
Pre-frail	144 (44.4)	84 (39.1)	60 (55.0)
Robust	137 (42.3)	113 (52.6)	24 (22.0)

BMI: Body Mass Index;

*p indicates the p-value that was based on Chi square, or Independent t-test.

Table 2 shows the association between frailty categories and disability status using binary logistic regression. In the fully adjusted model, model 2 shows that pre-frail (OR: 2.62; 95% CI [1.44, 4.79], p = 0.002) and frail (OR: 4.05; 95% CI [1.69, 9.65], p = 0.002) groups were significantly associated with having disability compared to robust group after adjustments for age, sex, BMI, and number of chronic conditions. The adjusted results indicate that participants in pre-frailty status were approximately twice as likely to have disability, and participants in frailty status were approximately four times as likely to have disability using ADL.

Table 2.

Binary logistic regression present the association between disability and frailty groups.

FRAIL scale	Model 11			Model 22
	OR (95% CI)			OR (95% CI)
	Non-Frail	Pre-frail	Frail	Non-Frail	Pre-frail	Frail
ADL	Reference	3.36 (1.93, 5.83)	6.53 (3.09, 13.83)	Reference	2.62 (1.44, 4.79)	4.05 (1.69, 9.65)

OR: Odds Ratio.

¹Model 1 unadjusted model.

²Model 2 adjusted for age, sex, BMI and number of chronic conditions.

Discussion

The current study assessed the association between disability levels and physical frailty in community-dwelling adults in Saudi Arabia. Our findings demonstrated a significant association between disability levels using ADL and physical frailty. Being prefrail or frail increased the odds of having disability as measured by an ADL scale.

The association between physical frailty and disability can be explained by the fact that physical frailty accelerates as individuals experience functional decline due to multimorbidity. A review by Fried et al. explains the co-occurrence of frailty, comorbidity, and disability⁹. They noted that existing literature supports a higher likelihood of finding a greater proportion of frail individuals among those who are disabled compared to those who are not. These association suggest the clinical importance of identify an appropriate intervention that could help in prevention progression of frailty.

Another mechanism that could explain this association between physical frailty and disability could be due to the lower levels of episodic memory and the change in orientation through ADL limitations. A recent study in China included 5431 older adults aged ≥ 60 years with physical frailty reported that pre-frail and frail adults have more ADL limitations, and in turn, they had lower levels of cognitive function²⁵. Hence, future research might need to include other extraneous variables such as cognitive function when investigating the underlying mechanisms of physical frailty and disability in older adults in which improving the understanding of these complex relationships.

Previous literature has been showed that physical frailty could predict disability^15,26. A systematic review of 28 cohort studies showed that the slow gait speed and low physical activity were the most powerful predictors of frailty that predict ADL disability¹⁵. A more recent systematic review and meta-analysis, including 71,544 older adults, showed that frailty was highly associated with disability, indicating that frail older people were more likely to develop disability compared to robust older people²⁶. None of the included studies in the thee previous reviews were conducted in Saudi Arabia. Therefore, the current study contributes to the literature in terms of context, population, and gaps related to the association between physical frailty and disability among Saudi population. Saudi Arabia has unique demographic, cultural, and environmental aspects that make the comparison with other countries difficult.

The present study showed that participants aged 50 years and older with physical frailty were more likely to have a disability using ADL. Similar results were obtained in the recent studies carried out by Ekram et al. and Hagiyama et al. In the research work of Ekram et al. it was reported that being prefrail and frail was associated with an increased risk of having physical disability^27,28. A 3-year retrospective cohort study by Hagiyama et al. suggested that both prefrail and frail were associated with the incidence of mild and severe disabilities among older adults aged ≥ 65 years²⁸. The finding showed that pre-frail participants had a higher prevalence of disability (55%) than both robust and frail participants, which may seem counterintuitive at first—especially it might be expected that frail individuals will show the highest rates of disability. Possible reasons include selected sample might be difficult to reach out people with severe disability; especially, frial group. People in the pre-frail group were more likely to be active and seeking medical attentions to measure disability outcomes. Imperatively, including wide age range of older adults (i.e., higher than 50 years old) might highlight the critical role of early detection of pre-frailty and prompt intervention in attenuating the progression of frailty and reducing the incidence of disability and other adverse health outcomes in older populations.

However, the agreement between our results and previous studies need to be taken with a caution due to differences between our study sample and outcome measures compared to previous literature. The study participants were 50 years and older while previous studies included older adults aged ≥ 65 years old^27,28. In addition, the outcome measures used to assess the frailty in our study was the Arabic version of FRAIL while previous studies used Fried frailty phenotype and Kihon Checklist. Further, the presence of disability was measured in our study using Arabic version of both ADL scale, whilest other studies assess physical disability according to Japanese government long-term care insurance (LTCI) certificate and six basic activities of daily living (BADLs) scale.

The findings observed in this study related to the association between physical frailty and disability suggested a substantial contribution to the global understanding of the relationship between these two constructs. Our results were consistent with previous studies that have demonstrated a strong association between physical frailty and disability across different populations and settings^9,15,29,30. By establishing a clear and robust association between physical frailty and disability, our study reinforces the notion that these two conditions are intrinsically linked³¹. Our findings align with Kojima’s conclusions, reinforcing the robust association between frailty and disability even when using different assessment tools and in distinct populations³⁵. Our study examined disability using two different scales, and the results were consistently significant between disability and frailty. Therefore, physical frailty and disability are highly prevalent issues across diverse cultures and societies. The association observed in our study enhances the generalizability of this relationship beyond specific regions or populations. Thus, future research should examine the bidirectional association between frailty and disability using a longitudinal design.

The findings of the current study shed light on the important insights of public health in Saudi Arabia as the aging population expands rapidly and the healthcare system becomes burdened by frailty-associated disabilities. Unlike most published studies in this area, our study considered the inclusion of the younger age group (50 years old) as the latest evidence in Saudi Arabia reported that the prevalence rate of disability among adults aged less than 60 years old was 3%³². Furthermore, 62.4% of the disability group have multiple chronic conditions, which could contribute to the development of disability. Recent evidence in Saudi Arabia reported that multimorbidity was considered as an important key factor strongly associated with being frail (OR: 1.96; 95%CI: 1.16–3.30³³. Furthermore, multimorbidity was significantly associated with an increased risk of disability (OR: 2.27, p = 0.007) among Saudi adults aged 50 years and older³⁴. The inclusion of this age group could help in early identification of frailty-associated disabilities and inform clinical strategies aimed at reversing or slowing the progression of frailty.

The results of the current study indicate that the association between disability level and frailty has significant clinical implications for healthcare strategies targeting older adults in Saudi Arabia. With the increasing prevalence of disability and frailty, as well as their strong relationship, identifying effective management strategies becomes essential. Recognizing frailty as an associated factor for disability through screening may guide the development of preventive strategies and interventions aimed at maintaining functional independence and quality of life among individuals at risk.

This study has some limitations that need to be mentioned. First, the current study’s cross-sectional design limits our ability to determine the causal relationship between disability and frailty. Second, we acknowledge the potential for bias introduced by including middle-aged adults, as frailty-related disability may manifest differently in this group compared to older adults aged ≥ 65 years. To address this, we performed adjusted analyses controlling for age, among other covariates, and observed that frailty remained significantly associated with disability even after these adjustments. Third, only ADLs scale was used, so future studies should include other measures like the Instrumental Activities of Daily Living (IADLs), which might provide additional information related to disability. Another limitation, although every effort has been made to minimize confounders, other unknown confounders might influence the results. Therefore, future research should examine the bidirectional association between frailty and disability using a longitudinal design. Finally, using a convenient sample in the current study limits the generalizability of our findings and is susceptible to selection bias. Therefore, future studies should include larger sample sizes and use random sampling methods to conduct large-scale studies at the national level and obtain generalizability.

Conclusion

This study highlights the association between physical frailty and disability among Saudi adults, emphasizing the need for interventions to mitigate the impact of physical frailty in order to promote healthy aging and improve quality of life. Further research is warranted to explore effective interventions that can address the modifiable associated factors associated with physical frailty, ultimately leading to the prevention or reduction of disability among Saudi adults.

Author contributions

BA and AMA conceived and designed the study. A.S.S, M.M.A. and M.A. helped with the data collection. B.A, N.A and M.A. helped with data analysis and interpretation. M.M.A., B.A.A., A.M.A.,N.A., M.A., and A.S.A. draft writing. All authors have read and agreed to the published version of the manuscript.

Data availability

The data will be available from the corresponding author based upon a reasonable request.

Declarations

Competing interests

The authors declare no competing interests.

Ethics committee approval

This study was approved by the Research Ethics Committee at Prince Sattam Bin Abdulaziz University (No. RHPT/022/010).