Abstract
Objective:
To investigate associations between leisure activities, examining each activity separately and in combination, and all-cause mortality among the Chinese oldest-old (≥ 80 years) population.
Design:
Prospective cohort study.
Setting:
Community-living, the oldest-old from 22 provinces in China.
Participants:
We included 30,070 Chinese individuals aged 80+ years (mean age: 92.7 years) from the Chinese Longitudinal Healthy Longevity Survey from 1998 to 2014.
Measurements:
Cox proportional hazards models were used to estimate relationships between leisure activities and all-cause mortality, adjusting for covariates including sociodemographic and lifestyle factors, self-reported medical history, and other potential confounders.
Results:
During 110,278 person-years of follow-up, 23,661 deaths were documented. Participants who engaged in watching TV or listening to the radio, playing cards or mah-jong, reading books or newspapers, gardening, keeping domestic animals or pets, or attending religious activities ‘almost every day’ had a significantly lower mortality risk (adjusted hazard ratios ranged from 0.82 to 0.89; P < 0.01 for all) than did participants who ‘never’ engaged in those activities. Furthermore, engagement in multiple leisure activities was associated with a reduced risk of all-cause mortality (P for the trend < 0.001).
Conclusions and Implications:
Frequent participation in leisure activities might help decrease the risk of death in the Chinese oldest-old population. This finding has important implications for public health policy and encourages the incorporation of a broad range of leisure activities into the daily lives of oldest-old individuals.
Keywords: leisure activity, mortality, oldest-old, cohort study
Introduction
Leisure activities usually constitute a relatively large part of daily life after retirement and may provide the social engagement and mental stimulation that were previously provided by employment. Consequently, the leisure activities of elderly people have been a common focus of studies examining several outcomes, such as cognitive function1–6, morbidity7,8, happiness and enhanced quality of life9,10. Emerging studies have indicated that frequent participation in leisure activities is associated with reduced all-cause mortality among the elderly. For instance, a prospective study conducted by Glass and colleagues11 showed that social and productive activities may be associated with a decrease in the risk of mortality among community-dwelling older adults. Another study reported that frequent engagement in social activities was associated with a reduced risk of mortality12. However, those studies were limited by relatively small sample sizes. In addition, Agahi and colleague13 conducted a prospective cohort study and found that frequent engagement in specific leisure activities, including gardening, reading books and dancing, was associated with a decreased risk of mortality. Nonetheless, evidence regarding the potential roles of these specific types of leisure activities on mortality is limited. The oldest-old population, composed of individuals aged 80+ years, constitutes the fastest growing segment of the elderly population (≥ 60 years) worldwide14. The Aging Committee of China expects that the number of oldest-old individuals in China will increase from approximately 22.7 million in 2013 to 30.7 million in 2020. However, most previous studies on relationships between leisure activities and mortality have focused on middle-aged or younger individuals13,15, and only a few studies of the oldest-old have been reported12. Within this context, inadequate representation of the oldest-old population in previous studies constitutes a knowledge gap.
We thus conducted a large, community-based prospective study of 30,070 Chinese oldest-old individuals, aiming to investigate associations between leisure activities, examining each activity separately and in combination, and all-cause mortality over a 16-year follow-up period.
Methods
Study setting and participants
The study used community-based, prospective data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Details of the study sample and design have been described previously16,17. Briefly, the study started in 1998 with a random selection of 631 cities/counties in 22 provinces of China; it was implemented in 2000, 2002, 2005, 2008, 2011 and 2014, with an estimated 90% response rate during each wave. We included the oldest-old individuals (80+ years) from the 1998 survey and newly recruited participants from the follow-up surveys. A flowchart of the participant enrollment process for this study is shown in Figure 1. The final sample was 30,070 participants. All information was obtained through face-to-face interviews, which were performed by a well-trained enumerator or local doctor/nurse. If respondents were unable to answer questions, the information was collected from proxy respondents (a spouse or close family member). Ethical approval for this study was obtained from the Ethics Committee of Peking University (IRB00001052-13074).
Fig. 1.
Flowchart of participant enrollment.
Ascertainment of deaths
In each follow-up survey, information on deaths was collected through interviews with close family members.
Assessment of leisure activities
At baseline, the participants were interviewed about their engagement in leisure activities in the past 6 months, including watching TV or listening to the radio, playing cards or mah-jong, reading newspapers or books, keeping domestic animals or pets, gardening, and attending religious activities. The frequency of participation in each activity was coded as ‘almost every day’, ‘sometimes’ or ‘never’. The binary participation in the leisure activities variable was coded as 1 if the answer was ‘almost every day’ or ‘sometimes’ and coded as 0 if the answer was ‘never’ for each leisure activity. We then summed the six leisure activities, and the resulting scale ranged from 0 to 6 points.
Ascertainment of covariates
Several potential confounders included in our analyses were selected based on previous literature6,11,17; the covariates included demographic characteristics (age, sex, education levels, occupation before age of 60, coresidence, residence, body mass index [BMI], and marital status), lifestyle factors (smoking status, alcohol consumption, regular physical activity, frequent fresh fruit consumption, and frequent vegetable consumption), self-reported diseases diagnosed by a doctor (hypertension, diabetes, heart disease and stroke), activities of daily living (ADLs), cognitive impairment and depressive symptoms. The Katz Activities of Daily Living Scale was used to assess the participants’ ADLs18. Information on regular physical activity was collected using the question ‘Do you do exercise regularly at present, including jogging, playing ball, running and Qigong’, and the answer was coded as yes or no. The Mini-Mental State Examination (MMSE) was measured at baseline, and an MMSE score less than 18 was considered to indicate cognitive impairment19. Information about all covariates was obtained using a standardized and structured questionnaire in the baseline survey. Participants were interviewed in their homes using a standard questionnaire (available at http://centerforaging.duke.edu/documentation).
Statistical analysis
For each participant, person-years of follow-up were calculated from the date of the baseline survey to the date of death, loss to follow-up or end of the follow-up period, whichever came first. The mean and standard deviation (SD) (continuous variables) or number and percentage (categorical variables) were used to describe the participants’ characteristics at baseline. We used the t-test or χ2 test to compare baseline characteristics of survivors or nonsurvivors at follow-up.
Cox proportional hazards models were applied to estimate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) for all-cause mortality associated with baseline leisure activities over the follow-up period, and each activity was assessed alone and in combination. Two sets of models were adopted. The basic model (model 1) was adjusted for baseline age (years) and sex (men or women). In the fully adjusted model (model 2), additional variables were adjusted, including education level (years), marital status (married or not married), occupation (white-collar or others), coresidence status (living alone or with others), residence status (urban or rural), smoking status (current smoker, former smoker, or nonsmoker), alcohol consumption (current drinker, former drinker, or nondrinker), frequent vegetable consumption (yes or no), frequent fruit consumption (yes or no), frequent physical activity (yes or no), ADL (restricted or normal), BMI (< 18.5, 18.5 to 23.9, or ≥ 24.0 kg/m2), diabetes mellitus (yes or no), heart disease (yes or no), hypertension (yes or no), stroke (yes or no), cognitive impairment (yes or no), depressive symptoms (yes or no), and participation in other leisure activities. Overall, less than 3% of the data for the study covariates at baseline were missing, and the multiple imputation method was used to correct for missing values and reduce the potential for inferential bias20. Moreover, we examined the associations between all-cause mortality and engagement in a number of leisure activities (range 0–6) in the fully adjusted model.
Subgroup analyses were performed according to age (< 90 and ≥ 90 years) and sex (men and women) groups using the fully adjusted models, and a likelihood ratio test was conducted to test for interactions. We conducted several sensitivity analyses to determine the robustness of our primary findings by the following: 1) adjusting for the year of recruitment; 2) restricting analyses to participants without missing covariate data; 3) excluding participants who died in the first two years of follow-up; and 4) performing analysis with Cox regression for time-varying leisure activities. All analyses were performed using R software, version 3.5.1 (R Development Core Team, 2018), with a type I error of 0.05.
Results
We included 30,070 Chinese oldest-old individuals (62.0% women; mean age: 92.7 years) in the present study. The characteristics of the participants at baseline are summarized in Table 1. Survivors were more likely than nonsurvivors to be men, residenting in urban, living alone, married, highly educated, have a higher BMI, exercise regularly, and have more frequent in eating vegetables and fruits. Conversely, compared to survivors, nonsurvivors tended to have a greater prevalence of diseases (hypertension and heart disease), depressive symptoms, cognitive impairment and ADL limitations.
Table 1.
Baseline characteristics of the study participants
| Characteristics | Total (n = 30070) |
No. (%) alive (n = 6409) |
No. (%) deceased (n = 23661) |
P |
|---|---|---|---|---|
| Age, mean (SD), (years) | 92.7 (7.5) | 89.3 (7.2) | 93.5 (7.3) | < 0.001 |
| Women | 18643 (62.0) | 3839 (59.9) | 14804 (62.6) | < 0.001 |
| Residence | < 0.001 | |||
| Urban | 12871 (42.8) | 3109 (48.5) | 9762 (41.3) | |
| Rural | 17199 (57.2) | 3300 (51.5) | 13899 (58.7) | |
| Coresidence | < 0.001 | |||
| Living alone | 4125 (13.7) | 1139 (17.8) | 2986 (12.6) | |
| Living with others | 25945 (86.3) | 5270 (82.2) | 20675 (87.4) | |
| Marital status | < 0.001 | |||
| Married | 5016 (16.7) | 1584 (24.7) | 3432 (14.5) | |
| Not married | 25054 (83.3) | 4825 (75.3) | 20229 (85.5) | |
| Education levels, years | < 0.001 | |||
| 0 | 21368 (71.1) | 4192 (65.4) | 17176 (72.6) | |
| ≥ 1 | 8702 (28.9) | 2217 (34.6) | 6485 (27.4) | |
| Occupation | < 0.001 | |||
| White-collar | 3916 (21.4) | 1108 (28.3) | 2808 (20.4) | |
| Others | 26154 (78.6) | 5333 (71.7) | 20821 (79.6) | |
| BMI, kg/m2 | < 0.001 | |||
| < 18.5 | 14771 (49.1) | 2685 (41.9) | 12086 (51.1) | |
| 18.5–23.9 | 12185 (40.5) | 2835 (44.2) | 9350 (39.5) | |
| ≥ 24.0 | 3114 (10.4) | 889 (13.9) | 2225 (9.4) | |
| Smoking status | 0.238 | |||
| Nonsmoker | 21342 (71.0) | 4521 (70.5) | 16821 (71.1) | |
| Current smoker | 4591 (15.3) | 1021 (15.9) | 3570 (15.1) | |
| Former smoker | 4137 (13.8) | 867 (13.5) | 3270 (13.8) | |
| Alcohol consumption | 0.030 | |||
| Nondrinker | 21413 (71.2) | 4612 (72.0) | 16749 (71.0) | |
| Current drinker | 5579 (18.6) | 1198 (18.7) | 4410 (18.5) | |
| Former drinker | 3078 (10.2) | 599 (9.3) | 2470 (10.5) | |
| Frequent vegetable consumption | 12162 (40.4) | 2406 (37.5) | 9756 (41.2) | < 0.001 |
| Frequent fruit consumption | 26212 (87.2) | 5436 (84.8) | 20776 (87.8) | < 0.001 |
| Regular physical activity | 20209 (67.2) | 3932 (61.4) | 16277 (68.8) | < 0.001 |
| Lung disease | 3289 (10.9) | 658 (10.3) | 2631 (11.1) | 0.055 |
| Hypertension | 13736 (45.7) | 2666 (41.6) | 11070 (46.8) | < 0.001 |
| Stroke | 1269 (4.2) | 270 (4.2) | 1004 (4.2) | 0.942 |
| Heart disease | 2117 (7.0) | 534 (8.3) | 1583 (6.7) | < 0.001 |
| Diabetes mellitus | 393 (1.3) | 113 (1.8) | 293 (1.2) | 0.051 |
| ADL limitations | 10095 (33.6) | 1273 (19.9) | 8822 (37.3) | < 0.001 |
| Depression | 543 (1.8) | 106 (1.7) | 437 (1.8) | < 0.001 |
| Cognitive impairment | 8415 (28.0) | 972 (15.2) | 7443 (31.5) | < 0.001 |
SD: standard deviation; BMI: body mass index; data are presented as n (percent) unless otherwise indicated.
During the 110,278 person-years of follow-up (median follow-up time: 2.9 years), 23,661 deaths were recorded. Table 2 presents specific leisure activities and their associations with the risk of mortality. In the basic model (model 1), compared to participants who ‘never’ engaged in leisure activities (watching TV or listening to the radio, reading books or newspapers, gardening, playing cards or mah-jong, keeping domestic animals or pets, and attending religious activities), participants who engaged in these activities ‘almost every day’ and ‘sometimes’ had a reduced risk of mortality (all P < 0.01, Table 2). In the fully adjusted model (model 2), compared to participants who ‘never’ engaged in leisure activities, a significantly reduced risk of death was observed among participants who engaged in watching TV or listening to the radio (HR: 0.83, 95% CI: 0.81–0.86), playing cards or mah-jong (HR: 0.89, 95% CI: 0.82–0.96), reading books or newspapers (HR: 0.86, 95% CI: 0.80–0.91), gardening (HR: 0.88, 95% CI: 0.82–0.94), keeping domestic animals or pets (HR: 0.82, 95% CI: 0.78–0.86), and attending religious activities (HR: 0.85, 95% CI: 0.78–0.93) ‘almost every day’ (Table 2). When examining the effects of engaging in multiple leisure activities on all-cause mortality, the analysis showed that engagement in an increasing number of leisure activities was associated with a decreased risk of all-cause mortality (P for the trend < 0.001) (Table 2).
Table 2.
Associations between leisure activities and all-cause mortality
| N/deaths | Model 1a | Model 2b | |||
|---|---|---|---|---|---|
| HR (95% CI) | P | HR (95% CI) | P | ||
| Watching TV or listening to the radio | |||||
| Never | 13485/11409 | 1.00 (reference) | - | 1.00 (reference) | - |
| Sometimes | 7302/5726 | 0.83 (0.81–0.86) | < 0.001 | 0.90 (0.87–0.93) | < 0.001 |
| Almost every day | 9283/6494 | 0.72 (0.70–0.75) | < 0.001 | 0.83 (0.81–0.86) | < 0.001 |
| Reading books or newspapers | |||||
| Never | 26081/20888 | 1.00 (reference) | - | 1.00 (reference) | - |
| Sometimes | 1832/1322 | 0.81 (0.76–0.85) | < 0.001 | 0.92 (0.86–0.98) | 0.006 |
| Almost every day | 2157/1419 | 0.71 (0.67–0.75) | < 0.001 | 0.86 (0.80–0.91) | < 0.001 |
| Gardening | |||||
| Never | 27102/21637 | 1.00 (reference) | - | 1.00 (reference) | - |
| Sometimes | 1424/1017 | 0.81 (0.76–0.86) | < 0.001 | 0.97 (0.91–1.03) | 0.332 |
| Almost every day | 1544/975 | 0.68 (0.64–0.73) | < 0.001 | 0.88 (0.82–0.94) | < 0.001 |
| Playing cards or mah-jong | |||||
| Never | 26737/21347 | 1.00 (reference) | - | 1.00 (reference) | - |
| Sometimes | 2266/1563 | 0.79 (0.75–0.84) | < 0.001 | 0.89 (0.84–0.94) | < 0.001 |
| Almost every day | 1067/719 | 0.75 (0.69–0.81) | < 0.001 | 0.89 (0.82–0.96) | 0.002 |
| Keeping domestic animals or pets | |||||
| Never | 24511/19452 | 1.00 (reference) | - | 1.00 (reference) | - |
| Sometimes | 2620/2070 | 0.84 (0.81–0.88) | < 0.001 | 0.90 (0.86–0.94) | < 0.001 |
| Almost every day | 2939/2107 | 0.76 (0.72–0.79) | < 0.001 | 0.82 (0.78–0.86) | < 0.001 |
| Religious activities | |||||
| Never | 26910/21396 | 1.00 (reference) | - | 1.00 (reference) | - |
| Sometimes | 2471/1745 | 0.80 (0.76–0.84) | < 0.001 | 0.93 (0.89–0.98) | 0.005 |
| Almost every day | 689/488 | 0.71 (0.65–0.77) | < 0.001 | 0.85 (0.78–0.93) | 0.003 |
| Number of leisure activities | |||||
| 0 | 8560/7587 | 1.00(reference) | - | 1.00(reference) | - |
| 1 | 8206/6622 | 0.79(0.76–0.81) | <0.001 | 0.84(0.82–0.87) | <0.001 |
| 2 | 6501/4796 | 0.66(0.64–0.69) | <0.001 | 0.74(0.71–0.77) | <0.001 |
| 3 | 4457/3110 | 0.58(0.55–0.62) | <0.001 | 0.68(0.67–0.72) | <0.001 |
| 4 | 1719/1136 | 0.54 (0.5–0.59) | <0.001 | 0.64(0.59–0.70) | <0.001 |
| 5 | 523/320 | 0.53(0.45–0.62) | <0.001 | 0.66(0.57–0.77) | <0.001 |
| 6 | 104/58 | 0.39(0.27–0.57) | <0.001 | 0.47(0.32–0.67) | <0.001 |
| P for trend | < 0.001 | < 0.001 | |||
HR: hazard ratio; CI: confidence interval.
Model 1: adjusted for age and sex;
Model 2: further adjusted for education level, occupation, marital status, living pattern, residence, smoking status, alcohol consumption, frequent vegetable consumption, frequent fruit consumption, regular physical exercise, BMI, hypertension, diabetes mellitus, lung disease, heart disease, depression symptoms, ADLs and participation in other leisure activities.
Subgroup analyses
We performed subgroup analysis stratified by sex (men and women) using the fully adjusted model (Table 3). Keeping domestic animals or pets resulted in a greater decrease in the risk of mortality in women than in men (P for interaction = 0.026). However, we found no significant effects of the interactions among men and women on the associations between other leisure activities (all P for interaction > 0.05). Furthermore, we performed subgroup analysis stratified by age group (< 90 and ≥ 90 years) (Table 4) and observed similar associations between leisure activities and all-cause mortality in participants < 90 years and ≥ 90 years of age (all P for interactions > 0.05).
Table 3.
Associations between leisure activities and all-cause mortality in groups stratified by sex
| Men (n = 11427) | Women (n = 18643) | P for interaction | |||||
|---|---|---|---|---|---|---|---|
| N/deaths | HR (95% CI)a | P | N/deaths | HR (95% CI) | P | ||
| Watching TV or listening to the radio | 0.233 | ||||||
| Never | 3801/3250 | 1.00 (reference) | - | 9684/8159 | 1.00 (reference) | - | |
| Sometimes | 2846/2244 | 0.88 (0.84–0.93) | < 0.001 | 4456/3482 | 0.91 (0.88–0.95) | < 0.001 | |
| Almost every day | 4780/3343 | 0.84 (0.79–0.89) | < 0.001 | 4503/3151 | 0.82 (0.79–0.86) | < 0.001 | |
| Reading books or newspapers | 0.316 | ||||||
| Never | 8238/6623 | 1.00 (reference) | - | 17843/14265 | 1.00 (reference) | - | |
| Sometimes | 1364/1004 | 0.92 (0.85–0.99) | 0.018 | 468/318 | 0.91 (0.85–1.02) | 0.107 | |
| Almost every day | 1825/1210 | 0.86 (0.80–0.93) | < 0.001 | 332/209 | 0.78 (0.68–0.91) | < 0.001 | |
| Gardening | 0.230 | ||||||
| Never | 9781/7728 | 1.00 (reference) | - | 17321/13909 | 1.00 (reference) | - | |
| Sometimes | 729/524 | 0.90 (0.84–0.97) | 0.007 | 695/493 | 0.94 (0.85–1.03) | 0.183 | |
| Almost every day | 917/585 | 0.88 (0.81–0.94) | < 0.001 | 627/390 | 0.86 (0.77–0.95) | < 0.001 | |
| Playing cards or mah-jong | 0.747 | ||||||
| Never | 9527/7528 | 1.00 (reference) | - | 17210/13819 | 1.00 (reference) | - | |
| Sometimes | 1327/924 | 0.89 (0.83–0.96) | 0.002 | 939/639 | 0.88 (0.81–0.96) | < 0.001 | |
| Almost every day | 573/385 | 0.86 (0.77–0.95) | 0.004 | 494/334 | 0.92 (0.82–1.02) | 0.125 | |
| Keeping domestic animals or pets | 0.026 | ||||||
| Never | 9151/7111 | 1.00 (reference) | - | 15360/12341 | 1.00 (reference) | - | |
| Sometimes | 1098/859 | 0.90 (0.84–0.97) | 0.007 | 1522/1211 | 0.90 (0.85–0.96) | < 0.001 | |
| Almost every day | 1178/867 | 0.88 (0.81–0.94) | < 0.001 | 1761/1240 | 0.79 (0.74–0.84) | < 0.001 | |
| Religious activities | 0.407 | ||||||
| Never | 10155/7929 | 1.00 (reference) | - | 16755/13467 | 1.00 (reference) | - | |
| Sometimes | 1024/738 | 0.92 (0.85–0.99) | 0.036 | 1447/1007 | 0.94 (0.88–1.01) | 0.070 | |
| Almost every day | 248/170 | 0.92 (0.79–1.08) | 0.305 | 441/318 | 0.83 (0.74–0.93) | 0.001 | |
| Number of leisure activities | 0.981 | ||||||
| 0 | 2180/1947 | 1.00 (reference) | - | 6380/5640 | 1.00 (reference) | - | |
| 1 | 2185/2290 | 0.83 (0.79–0.88) | < 0.001 | 5391/4332 | 0.85 (0.82–0.88) | < 0.001 | |
| 2 | 2713/2072 | 0.74 (0.70–0.79) | < 0.001 | 3755/2724 | 0.73 (0.70–0.77) | < 0.001 | |
| 3 | 2183/1544 | 0.67 (0.62–0.73) | < 0.001 | 2274/1566 | 0.68 (0.63–0.74) | < 0.001 | |
| 4 | 1087/706 | 0.63 (0.57–0.70) | < 0.001 | 632/430 | 0.64 (0.56–0.74) | < 0.001 | |
| 5 | 386/242 | 0.65 (0.55–0.78) | < 0.001 | 137/78 | 0.67 (0.50–0.91) | < 0.001 | |
| 6 | 63/36 | 0.43 (0.26–0.71) | < 0.001 | 41/22 | 0.55 (0.30–0.85) | < 0.001 | |
HR: hazard ratio; CI: confidence interval.
Adjusted for age, sex, education level, occupation, marital status, living pattern, residence, smoking status, alcohol consumption, frequent vegetable consumption, frequent fruit consumption, regular physical exercise, BMI, hypertension, diabetes mellitus, lung disease, heart disease, depression symptoms, ADLs and participation in other leisure activities.
Table 4.
Associations between leisure activities and all-cause mortality in groups stratified by age
| < 90 years (n = 10673) | ≥ 90 years (n = 19397) | P for interaction | |||||
|---|---|---|---|---|---|---|---|
| N/deaths | HR (95% CI)a | P | N/deaths | HR (95% CI) | P | ||
| Watching TV or listening to the radio | 0.122 | ||||||
| Never | 3315/2454 | 1.00 (reference) | - | 10170/8955 | 1.00 (reference) | - | |
| Sometimes | 2834/1939 | 0.86 (0.81–0.91) | < 0.001 | 4468/3787 | 0.92 (0.88–0.96) | < 0.001 | |
| Almost every day | 4524/2715 | 0.79 (0.74–0.84) | < 0.001 | 4759/3779 | 0.86 (0.82–0.90) | < 0.001 | |
| Reading books or newspapers | 0.694 | ||||||
| Never | 8486/5758 | 1.00 (reference) | - | 17595/15130 | 1.00 (reference) | - | |
| Sometimes | 964/624 | 0.91 (0.83–1.00) | 0.051 | 868/698 | 0.91 (0.84–0.99) | 0.033 | |
| Almost every day | 1223/726 | 0.81 (0.74–0.90) | < 0.001 | 934/693 | 0.88 (0.81–0.96) | 0.001 | |
| Gardening | 0.673 | ||||||
| Never | 9029/6121 | 1.00 (reference) | - | 18073/15516 | 1.00 (reference) | - | |
| Sometimes | 724/466 | 0.99 (0.90–1.09) | 0.880 | 700/551 | 0.95 (0.87–1.04) | 0.289 | |
| Almost every day | 920/521 | 0.90 (0.82–0.99) | 0.027 | 624/454 | 0.87 (0.79–0.95) | 0.004 | |
| Playing cards or mah-jong | 0.804 | ||||||
| Never | 8774/5937 | 1.00 (reference) | - | 17963/15410 | 1.00 (reference) | - | |
| Sometimes | 1248/775 | 0.87 (0.81–0.94) | < 0.001 | 1018/788 | 0.91 (0.85–0.98) | 0.014 | |
| Almost every day | 651/396 | 0.89 (0.80–0.99) | 0.033 | 416/323 | 0.89 (0.79–0.99) | 0.038 | |
| Keeping domestic animals or pets | 0.613 | ||||||
| Never | 7851/5219 | 1.00 (reference) | - | 16660/14233 | 1.00 (reference) | - | |
| Sometimes | 1140/811 | 0.91 (0.85–0.98) | 0.019 | 1480/1259 | 0.90 (0.85–0.96) | < 0.001 | |
| Almost every day | 1682/1078 | 0.84 (0.78–0.90) | < 0.001 | 1257/1029 | 0.83 (0.78–0.89) | < 0.001 | |
| Religious activities | 0.107 | ||||||
| Never | 9104/6131 | 1.00 (reference) | - | 9104/6131 | 1.00 (reference) | - | |
| Sometimes | 1249/779 | 0.95 (0.88–1.02) | 0.178 | 1249/779 | 0.93 (0.87–0.99) | 0.030 | |
| Almost every day | 320/198 | 0.97 (0.84–1.12) | 0.668 | 320/198 | 0.80 (0.71–0.90) | < 0.001 | |
| Number of leisure activities | 0.271 | ||||||
| 0 | 1338/1099 | 1.00 (reference) | - | 7222/6488 | 1.00 (reference) | - | |
| 1 | 2432/1721 | 0.80 (0.74–0.85) | < 0.001 | 5774/4901 | 0.86 (0.83–0.89) | < 0.001 | |
| 2 | 2900/1859 | 0.70 (0.65–0.75) | < 0.001 | 3601/2937 | 0.76 (0.73–0.80) | < 0.001 | |
| 3 | 2494/1539 | 0.62 (0.57–0.68) | < 0.001 | 1963/1571 | 0.73 (0.68–0.78) | < 0.001 | |
| 4 | 1084/644 | 0.61 (0.54–0.68) | < 0.001 | 635/492 | 0.67 (0.59–0.75) | < 0.001 | |
| 5 | 359/211 | 0.63 (0.51–0.78) | < 0.001 | 164/109 | 0.68 (0.54–0.86) | < 0.001 | |
| 6 | 66/35 | 0.43 (0.26–0.71) | < 0.001 | 38/23 | 0.49 (0.29–0.85) | < 0.001 | |
HR: hazard ratio; CI: confidence interval.
Adjusted for age, sex, education level, occupation, marital status, living pattern, residence, smoking status, alcohol consumption, frequent vegetable consumption, frequent fruit consumption, regular physical exercise, BMI, hypertension, diabetes mellitus, lung disease, heart disease, depression symptoms, ADLs and participation in other leisure activities.
Sensitivity analysis
Moreover, our sensitivity analyses did not detect material changes in the results after additionally adjusting for the time of recruitment (Table 1S) and the exclusion of participants with missing covariate data (Table 2S). Similarly, restricting the analyses to subjects with at least 2 years of follow-up data to further reduce the effect of ‘reverse causality’ did not materially change the observed associations (Table 3S). Moreover, material changes in the results were not observed after implementing the time-varying Cox regression (Table 4S).
Discussion
In analyses based on a large cohort of Chinese community-dwelling oldest-old individuals, frequent participation in leisure activities, including watching TV or listening to the radio, playing cards or mah-jong, reading newspapers or books, keeping domestic animals or pets, gardening, and attending religious activities, was associated with a lower risk of mortality, even after fully adjusting for potential confounding factors, such as socioeconomic status, lifestyle factors, presence of diseases, ADLs, and cognitive function at baseline. Furthermore, the HR of all-cause mortality progressively decreased with engagement in an increasing number of those leisure activities.
Previous studies have presented evidence that prolonged TV watching potentially leads to an increased risk of all-cause mortality among elderly people21,22, though our study indicated that frequent TV watching may decrease the risk of mortality; this is, prolonged viewing time may increase the risk of death, but watching TV alone may lead to a decreased risk of death among the oldest-old. The explanations for this finding might be that the Chinese oldest-old individuals have few other sources of information and may find TV watching intellectually challenging and informative, which may preserve cognitive function and reduce the risk of mortality among elderly people23. The results from our study are consistent with a previous study that examined reduced all-cause mortality among elderly participants who frequently played cards or mah-jong24. This finding may be explained by the fact that playing cards or mah-jong (a Chinese tile-based game) establishes interpersonal social contact, which is also known to be associated with a reduced risk of mortality. Moreover, according to a study by Bygren et al.25, reading books or newspapers may exert a positive effect on survival. The results of our study are consistent with the findings of that study, as more frequent reading of books or newspapers was associated with a lower risk of mortality among the oldest-old population. The possible mechanism underlying the positive effect is that the survival advantage of reading books is exerted through a cognitive function mediator26. Thus, the findings of previous studies and the current study suggest that frequent engagement in intellectual activities (playing cards or mah-jong, reading books or newspapers) may exert a protective effect and decrease the risk of all-cause mortality in later life.
Religious philosophies of Chinese and Western cultures differ substantially27. Based on emerging evidence, active participation in religious activities by populations in Western countries exerts protective effects on health outcomes28–30, particularly by reducing the risk of mortality31–33. Consistent with this finding, frequent engagement in religious activity was associated with a reduced risk of all-cause mortality in the present study. Moreover, data from the 2000–2005 waves of the CLHLS, Zeng et al.34 revealed a beneficial effect of attending religious activities on the risk of mortality in the oldest-old population. This finding might be explained by the fact that religious activity encourages a positive lifestyle among participants and creates positive expectations34. Therefore, frequent engagement in Chinese religious activities is also likely to be associated with a reduced risk of all-cause mortality.
Furthermore, this study indicated that the risk of all-cause mortality progressively decreased with engagement in an increasing number of leisure activities. Similarly, a previous study11 showed that elderly people who engaged in an increasing number of activities were less likely to die than were those who engaged in few activities. Our study also found that the association between mortality and leisure activates, including watching TV or listening to the radio, playing cards or mah-jong, reading newspapers or books, keeping domestic animals or pets, and attending religious activities, was similar in men and women. Thus, encouraging both men and women to participate in these activities can help reduce the risk of death.
To the best of our knowledge, the present study is the largest prospective cohort study to investigate associations between leisure activities and the risk of all-cause mortality in the oldest-old population. The strengths of our study include the community-based, prospective design, the large sample of oldest-old individuals, the ability to control for many potential confounding factors, and the robust results of sensitivity analyses. These findings have important implications for public health policy and can be used to encourage the incorporation of a broad range of leisure activities into the daily lives of the oldest-old.
Several limitations of this study should be considered. First, the current sample was composed of Chinese oldest-old individuals, and the results obtained might not apply to populations in Western countries. Thus, caution should be taken when extrapolating these conclusions to other populations or countries. Second, although the analyses were adjusted for several covariates, some residual confounding is possible. Third, the factors assessed did not include information about the duration, intensity, or energy expenditure of the activities, possibly leading to imprecise measurements. Fourth, we only inquired about a limited number of leisure activities; thus, the number of activities assessed was not consistent across different activity types (e.g., social and productive activities). Therefore, further studies including more leisure activities, such as shopping and community work, are needed to more comprehensively assess the relationship between leisure activity and death. In addition, the longitudinal relationship might be explained by ‘reverse causality’, in which a decrease in participation in leisure activities would occur in the early stages of the death process due to weakness. However, in the current study, we excluded the first two years of the follow-up period to minimize the reverse causation bias and did not observe a meaningful change in the results.
Conclusions and Implications
In conclusion, this large, statistically powerful study suggests that a greater frequency of participation in specific leisure activities, including playing cards and mah-jong and watching TV, potentially results in lower mortality among the oldest-old Chinese population. More comprehensive studies are needed to improve our knowledge of associations between participation in leisure activities and survival, as well as the mechanisms that cause and explain these associations.
Funding:
The Chinese Longitudinal Healthy Longevity Study (CLHLS), which provided the data analyzed in this paper, is jointly supported by the National Natural Sciences Foundation of China (81573207, 71233001, 71490732 and 81573247), and the U.S. National Institute of Aging (2P01AG031719 and 3P01AG031719-07S1). This work was also supported by the National Key Research and Development Program of China (2018YFC2000400) and the Construction of High-level University of Guangdong (C1050008 and C1051007). The funders played no role in the study design or implementation; data collection, management, analysis, or interpretation; manuscript preparation, review, or approval; or the decision to submit the manuscript for publication.
Appendix
Table 1S.
Association between leisure activities and all-cause mortality additionally adjusting for time of recruitment
| All-cause mortality | ||
|---|---|---|
| HR (95% CI) | P | |
| Watching TV or listening to radio | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.90 (0.87–0.93) | < 0.001 |
| Almost every day | 0.81 (0.79–0.84) | < 0.001 |
| Reading books or newspapers | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.91 (0.86–0.96) | 0.002 |
| Almost every day | 0.87 (0.82–0.93) | < 0.001 |
| Gardening | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.97 (0.90–1.03) | 0.296 |
| Almost every day | 0.87 (0.82–0.93) | < 0.001 |
| Playing cards or mah-jong | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.89 (0.84–0.94) | < 0.001 |
| Almost every day | 0.88 (0.82–0.95) | < 0.001 |
| Keeping domestic animals or pets | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.89 (0.84–0.94) | < 0.001 |
| Almost every day | 0.88 (0.82–0.95) | 0.003 |
| Religious activities | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.94 (0.89–0.99) | 0.016 |
| Almost every day | 0.88 (0.80–0.96) | 0.004 |
| Number of leisure activities | ||
| 0 | 1.00 (reference) | - |
| 1 | 0.84 (0.81–0.87) | < 0.001 |
| 2 | 0.74 (0.71–0.77) | < 0.001 |
| 3 | 0.68 (0.64–0.72) | < 0.001 |
| 4 | 0.63 (0.58–0.69) | < 0.001 |
| 5 | 0.65 (0.58–0.69) | < 0.001 |
| 6 | 0.46 (0.32–0.66) | < 0.001 |
| P for trend | < 0.001 | |
HR: hazard ratio; CI: confidence interval;
Adjusted for age and sex, education level, occupation, marital status, living pattern and residence, smoking status, alcohol consumption, frequent vegetable consumption, frequent fruit consumption, regular exercise, BMI, hypertension, diabetes mellitus, lung disease, heart disease, depression symptoms, ADLs and participation in other leisure activities.
Table 2S.
Association between leisure activities and all-cause mortality after excluding participants with missing data on covariates.
| All-cause mortality | ||
|---|---|---|
| HR (95% CI) | P | |
| Watching TV or listening to radio | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.90 (0.87–0.93) | < 0.001 |
| Almost every day | 0.84 (0.81–0.87) | < 0.001 |
| Reading books or newspapers | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.91 (0.86–0.97) | 0.002 |
| Almost every day | 0.86 (0.80–0.91) | < 0.001 |
| Gardening | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.91 (0.86–0.94) | < 0.001 |
| Almost every day | 0.82 (0.78–0.86) | < 0.001 |
| Playing cards or mah-jong | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.89 (0.85–0.94) | < 0.001 |
| Almost every day | 0.89 (0.82–0.96) | < 0.001 |
| Keeping domestic animals or pets | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.99 (0.92–1.06) | 0.753 |
| Almost every day | 0.86 (0.80–0.92) | < 0.001 |
| Religious activities | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.96 (0.92–1.01) | 0.138 |
| Almost every day | 0.87 (0.80–0.96) | 0.004 |
| Number of leisure activities | ||
| 0 | 1.00 (reference) | - |
| 1 | 0.84 (0.81–0.87) | < 0.001 |
| 2 | 0.75 (0.72–0.78) | < 0.001 |
| 3 | 0.70 (0.67–0.74) | < 0.001 |
| 4 | 0.64 (0.58–0.78) | < 0.001 |
| 5 | 0.67 (0.57–0.78) | < 0.001 |
| 6 | 0.49 (0.35–0.78) | < 0.001 |
| P for trend | < 0.001 | |
HR: hazard ratio; CI: confidence interval;
Adjusted for age and sex, education level, occupation, marital status, living pattern and residence, smoking status, alcohol consumption, frequent vegetable consumption, frequent fruit consumption, regular exercise, BMI, hypertension, diabetes mellitus, lung disease, heart disease, depression symptoms, ADLs and participation in other leisure activities.
Table 3S.
Association between leisure activities and all-cause mortality excluding participants who died in the first two years of follow-up
| All-cause mortality | ||
|---|---|---|
| HR (95% CI) | P | |
| Watching TV or listening to radio | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.88 (0.84–0.92) | < 0.001 |
| Almost every day | 0.83 (0.80–0.87) | < 0.001 |
| Reading books or newspapers | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.90 (0.84–0.97) | 0.005 |
| Almost every day | 0.82 (0.76–0.89) | < 0.001 |
| Gardening | ||
| Never | 1.00 (reference) | - |
| Sometimes | 1.00 (0.92–1.08) | < 0.001 |
| Almost every day | 0.85 (0.78–0.92) | < 0.001 |
| Playing cards or mah-jong | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.88 (0.82–0.93) | < 0.001 |
| Almost every day | 0.90 (0.83–0.98) | 0.018 |
| Keeping domestic animals or pets | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.89 (0.84–0.95) | < 0.001 |
| Almost every day | 0.85 (0.80–0.90) | < 0.001 |
| Religious activities | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.94 (0.83–1.00) | 0.046 |
| Almost every day | 0.92 (0.83–0.99) | 0.037 |
| Number of leisure activities | ||
| 0 | 1.00 (reference) | - |
| 1 | 0.86 (0.82–0.90) | < 0.001 |
| 2 | 0.75 (0.71–0.78) | < 0.001 |
| 3 | 0.70 (0.62–0.71) | < 0.001 |
| 4 | 0.63 (0.62–0.70) | < 0.001 |
| 5 | 0.66 (0.56–0.79) | < 0.001 |
| 6 | 0.46 (0.31–0.69) | < 0.001 |
| P for trend | < 0.001 | |
HR: hazard ratio; CI: confidence interval;
Adjusted for age and sex, education level, occupation, marital status, living pattern and residence, smoking status, alcohol consumption, frequent vegetable consumption, frequent fruit consumption, regular exercise, BMI, hypertension, diabetes mellitus, lung disease, heart disease, depression symptoms, ADLs and participation in other leisure activities.
Table 4S.
Association between leisure activities and all-cause mortality after performing analysis with Cox regression for time-varying leisure activities
| All-cause mortality | ||
|---|---|---|
| HR (95% CI) | P | |
| Watching TV or listening to radio | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.92 (0.87–0.95) | < 0.001 |
| Almost every day | 0.83 (0.79–0.87) | < 0.001 |
| Reading books or newspapers | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.94 (0.86–1.02) | 0.168 |
| Almost every day | 0.83 (0.75–0.91) | < 0.001 |
| Gardening | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.98 (0.91–1.02) | 0.162 |
| Almost every day | 0.89 (0.83–0.96) | < 0.001 |
| Playing cards or mah-jong | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.92 (0.86–0.97) | < 0.001 |
| Almost every day | 0.89 (0.84–0.95) | < 0.001 |
| Keeping domestic animals or pets | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.99 (0.91–1.07) | 0.825 |
| Almost every day | 0.85 (0.79–0.91) | < 0.001 |
| Religious activities | ||
| Never | 1.00 (reference) | - |
| Sometimes | 0.93 (0.84–0.98) | < 0.001 |
| Almost every day | 0.88 (0.77–0.98) | 0.014 |
HR: hazard ratio; CI: confidence interval;
Adjusted for age and sex, education level, occupation, marital status, living pattern and residence, smoking status, alcohol consumption, frequent vegetable consumption, frequent fruit consumption, regular exercise, BMI, hypertension, diabetes mellitus, lung disease, heart disease, depression symptoms, ADLs and participation in other leisure activities.
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