Revised: 18 January 2023

Accepted: 19 January 2023

DOI: 10.1111/jgs.18269

Journal of theAmerican Geriatrics Society

CLINICAL INVESTIGATION

Social participation and incident disability and mortality
among frail older adults: A JAGES longitudinal study
Noriyuki Abe PT, MSc 1,2| Kazushige Ide PT, PhD 1,3
1,4,5

Ryota Watanabe PT, PhD
Genmei Iizuka MD, MSc 1,2,7|| Takahiro Hayashi PT, PhD 6|
1,8| Katsunori Kondo MD, PhD

1

Department of Social Preventive Medical Sciences, Center for Preventive Medical Sciences, Chiba University, Chiba, Japan2

Department of Public Health, Graduate School of Medicine, Chiba University, Chiba, Japan3

Department of Community General Support, Hasegawa Hospital, Chiba, Japan

4

Center for Well-being and Society, Nihon Fukushi University, Nagoya City, Aichi, Japan

5

Department of Frailty Research, Research Institute, Center for Gerontology and Social Science, National Center for Geriatrics and Gerontology,
Aichi, Japan

6

Department of Rehabilitation and Care, Seijoh University, Aichi, Japan

7

Seibo International Catholic Hospital Family Medicine Residency, Tokyo, Japan

8

Department of Geriatric Evaluation, Center for Gerontology and Social Science, Research Institute, National Center for Geriatrics and Gerontology,
Aichi, Japan

Correspondence
Noriyuki Abe, Department of Social
Preventive Medical Sciences, Center for
Preventive Medical Sciences, Chiba
University, 1-33, Yayoi-cho, Inage-ku,
Chiba-city, Chiba, Japan.
Email: naloe1021@gmail.com
Funding information
Chiba Foundation for Health Promotion
and Disease Prevention; Health Labour
Sciences Research Grant, Grant/Award
Numbers: 19FA1012, 19FA2001,
21GA0101, H28-Choju-Ippan-002;
Innovative Research Program on Suicide
Countermeasures, Grant/Award Number:
1-4; Japan Agency for Medical Researchand Development, Grant/Award
Numbers: JP18dk0110027, JP18le0110009,
JP18ls0110002, JP20dk0110034,
JP21dk0110037, JP21lk0310073; Japan
Health Promotion and Fitness
Foundation; Japan Society for the
Promotion of Science, Grant/Award
Numbers: 19K20909, 20H00557,
JP15H01972; Meiji Yasuda Life

Abstract
Background: Frailty is the highest risk factor for incident disability andmortality. Social participation is a modifiable factor for reducing adverse outcomes among independent older adults. However, the association between social
participation and incident disability and mortality among frail older adults
remains unclear. Therefore, we examined the association between various social
activities and incident disability and mortality.
Methods: This nationwide prospective cohort study (The Japan Gerontological Evaluation Study) recruited older adults with frailty, aged 65 years andolder (N = 9090) who were followed up for 6 years (2010–2016). We examined
incident disability and all-cause mortality at the end of the follow-up period.
Frailty was assessed using the Kihon Checklist. The independent variable wassocial participation in 2010, grouped into the following seven categories: hobby
groups, sports groups or clubs, volunteer groups, senior citizens' clubs, industries, neighborhood communities, and paid work.
Results: The incidence of disability among participants was 19.5% (1770) andthat of mortality was 19.2% (1753). Belonging to sports groups or clubs (Hazard
Ratios [HR] = 0.74; 95% Confidence Interval [CI] = 0.57, 0.98) or hobby groups(HR = 0.77; 95% CI = 0.60, 0.98) was significantly associated with a lower riskThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any
medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
© 2023 The Authors. Journal of the American Geriatrics Society published by Wiley Periodicals LLC on behalf of The American Geriatrics Society.
J Am Geriatr Soc. 2023;1–10.

wileyonlinelibrary.com/journal/jgs

115325415, 0, Downloaded from https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/jgs.18269 by Cochrane Japan, Wiley Online Library on [07/02/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

Received: 2 November 2022

ABE ET AL.

Foundation of Health and Welfare and the
Research Funding for Longevity Sciencesfrom National Center for Geriatrics andGerontology, Grant/Award Numbers:
20-19, 21-20, 29-42, 30-22; Program on
Open Innovation Platform withEnterprises, Research Institute andAcademia, Grant/Award Number:
JPMJOP1831; Sasakawa Sports
Foundation, Grant/Award Number:
19-2-06of incident disability. Meanwhile, hobby groups (HR = 0.68; 95% CI = 0.56,0.83), sports groups or clubs (HR = 0.71; 95% CI = 0.57, 0.88), volunteer groups(HR = 0.69; 95% CI = 0.54, 0.88), and senior citizens' club (HR = 0.75; 95%
CI = 0.61, 0.90) were associated with lower risk of incident mortality.
Conclusions: Social participation was associated with a lower risk of incident
disability and mortality, not only in healthy older adults but also in frail older
adults who are at higher risk of incident disability and mortality. This suggeststhat frail older adults should be encouraged to participate in all the seven typesof social participation examined in this study, as this may lower the risk of subsequent disability and mortality.
KEYWORDS

frailty, long-term care, mortality, social participation

INTRODUCTION
Key points
1

With the rapidly aging population, the population offrail older adults is increasing worldwide.2,3 Frailty isdefined as loss of reserve capacity in multiple physiological systems and results in increased vulnerability to various stressors.4 Frailty increases the risk of developing
several adverse health outcomes, such as fractures, incident disability, hospitalization, institutionalization, andmortality.5–7 Particularly, frailty compared with nonfrailty and pre-frailty is the highest risk factor for adverse
health outcomes. Therefore, it is important for clinicalpractitioners and public health experts to prevent the
progression from frailty to adverse health outcomes.
Among community-dwelling older adults, social participation is one of the modifiable factors for reducing adverse
health outcomes, such as incident disability, including
functional and cognitive aspects,8–14 and mortality.13,14
Social participation comprises various concepts and types,
including leisure activities, meeting friends, volunteering,and others.15 A previous study15 classified activities into six
levels (levels 1–6), with social participation considered torange from level 2 (talking to neighbors) to level 6 (engaging
in political and socially oriented activities). Particularly,social activities (e.g., sports groups or clubs, hobby groups,
and paid work) reduce the risk of functional disability.8,12
In addition, these activities have gained increasing attention
in recent aging research because of their relatively low cost,
accessibility, and health benefits.16
However, evidence about social participation among
frail older adults is still limited. A study reported that
community-based self-management activities in frail
older adults effectively reduced incident disability.6 Frailolder adults benefit longitudinally from participating insporting, cultural, and social activities, which manifest as
improvement in physical function and well-being.17 Frail• The percentages of participation in different
social activities among frail older adults vary
widely by type, with participation in neighborhood communities and hobby groups exceeding 20%.
• In this nationwide Japanese cohort, frail older
adults who participated in hobby groups orsports groups, or clubs were at lower risk ofincident disability and mortality.
• The lower risk of incident disability and mortality due to social participation is not only limited to healthy older adults but also occurs infrail older adults.
Why does this paper matter?
This study encourages social participation toextend the healthy life expectancy of frail older
adults.

older adults participate in various activities, but noprevious studies have examined how these activities are
longitudinally associated with incident disability andmortality. In addition, no validation study based onlarge-scale longitudinal data of multi-municipalities has
been performed. The social participation of frail older
adults is influenced by the built environment, including
the physical environment.18 Using large longitudinaldata, we can clarify the association between social participation and mortality among frail older adults, including
the built environment, which has not been considered inprevious studies.

15325415, 0, Downloaded from https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/jgs.18269 by Cochrane Japan, Wiley Online Library on [07/02/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License2

In this study, we examined the association of various
social participations with incident disability and mortality
using large-scale longitudinal data from Japan to control
for confounding resulting from the physical environment,
which was not accounted for in previous studies. This
study closes a potential gap in the evidence on the potential effect of social participation among frailty older adults.
By examining the effects of various types of social participation for frail older adults, policymakers and researchers
can provide evidence to encourage new social participation activities for frail older adults.

METHODS
Data sources
We used longitudinal cohort data from the 2010 waves of
the Japan Gerontological Evaluation Study (JAGES),19,20
which is a nationwide gerontological survey in Japan,
focused on social determinants of health and social environment. The baseline survey was conducted between August2010 to January 2012 among 95,827 older adults aged
65 years or older living in 13 municipalities of seven prefectures in Japan, including both rural and urban areas. The
participants were not certified to receive long-term care. A
random sampling method was used in the 4 large municipalities, while the self-administered questionnaire was sent
by mail to all eligible residents in 9 small municipalities.
Among the 62,426 respondents (response rate: 65.1%),
56,587 respondents had valid information on ID number,sex, and age. Among the 56,587 respondents, 54,537 (96.2%)
were successfully linked with the records of the national
long-term care insurance (LTCI) database containing information on the onset of all-cause mortality between August2010 and December 2016. We excluded 991 individuals fromthe baseline survey due to limitations in and missing
responses regarding performing basic activities of daily livingsuch as walking, bathing, and toileting. In addition, 27,920
individuals who were determined as non-frail based on the
Kihon Checklist (KCL)21–23 and 15,051 individuals withincomplete responses to the KCL items were excluded.
Finally, 9090 eligible frail older adults (5012 women) were
included.

Frailty
Frailty was assessed using the KCL, developed by theJapanese Ministry of Health, Labour, and Welfare. The
KCL is a simple yes/no questionnaire that assesses multiple aspects of daily living functions, such as physicalstrength, nutrition, eating habits, socialization, memory,3

mood, and lifestyle.21,24,25 Each item was scored yes = 1 or
no = 0, with a total score ranging from 0 to 25 and ahigher score indicating worse functioning. The KCL isstrongly associated with the Cardiovascular HealthStudy criteria for frailty based on Fried's Phenotypic
Model4 with the sensitivity and specificity of these cutoff values being 89.5% and 80.7%,22 respectively. In addition, the predictive validity of new support and careneeds certifications and deaths has been reported.22 Basedon previous studies,22–24,26 frailty (≥8 points) was defined,
and the non-frail (0–7 points) was excluded from this study.
The JAGES participants were informed that participation was voluntary and that returning the questionnaire
implied consent to participate in the study. Our research
protocol and informed consent method were approved by
the Ethics Committees of Chiba University (approval
number: 2493), the National Center for Geriatrics andGerontology (approval number: 992), and Nihon Fukushi
University (approval number: 10–05).

Incident disability and mortality
We examined incident disability and all-cause mortality atthe end of the 6-year observational period. Incident disability was assessed based on the LTCI system, that is, theneed for nursing care and the situation. Disability classification was subdivided into the following seven levels: support needed (support levels 1 and 2) and nursing careneeded (care levels 1–5).27,28 To address the possibility offunctional disability regardless of social participation, thefunctional disability outcome was defined as care levels
2 or higher, excluding support levels 1 and 2 and care level
1, which are considered mild functional disabilities.27,29

Social participation
The independent variable was social participation, which
was recorded from the baseline survey. Based on the six
levels of social activities15 and previous studies,8,12 weclassified social participation into the following sevengroups; participation in hobby groups, sports groups
or clubs, volunteer clubs, senior citizens' clubs, industries,
neighborhood communities, and paid work. The organization that is particularly unique to Japan among
the social participation types is senior citizens' clubs,
industries, and neighborhood communities. Japan's
senior citizens' clubs organize a wide range of activities,
including group activities such as sports, hobbies, culturalactivities, and performing arts. In addition, industries
are interest groups composed of companies and individuals involved in a particular industry as its members.

15325415, 0, Downloaded from https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/jgs.18269 by Cochrane Japan, Wiley Online Library on [07/02/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

SOCIAL PARTICIPATION, DISABILITY, AND MORTALITYNeighborhood community is a voluntary or local association organized by residents and others in a community orpart of a city in Japan for friendship, promotion of common interests, and local self-government, as well as its
meetings and gatherings.
Participants were asked, “How often do you participate in the following groups or clubs?” Participants chosean option from the following choices: “almost every day,”“twice or thrice a week,” “once a week,” “once or twice amonth,” “a few times a year,” and “never.” The responses
were categorized as “yes” if individuals selected any of
the five options from “a few times a year” to “almost
every day,” and “no” if they selected “never.” Participation in work was assessed using the following question:“What is your current working status?” Participantschose from the following options: “working,” “retired
and not working now,” and “never had a job.” The
response was categorized as “yes” if the participants
answered, “working” and “no” if they answered, “retired
and not working now,” or “never got a job.”

ABE ET AL.

TABLE 1survey.

Basic characteristics of participants at the baseline

Baseline characteristics

Total (N = 9090)

Age (years)
65–69

1747 (19.2)

70–74

2264 (24.9)

75–792300 (25.3)

80–84

1749 (19.2)≥85
Sex, women

1030 (11.3)
5012 (55.1)

Annual equivalent income (million yen)
Low (<2.0)4252 (46.8)

Middle (2.0–3.9)

2493 (27.4)

High (≥4.0)

2345 (25.8)

Educational attainment (years)
Low (<10)5131 (57.6)

Middle (10–12)

2653 (29.8)

High (≥13)

1126 (12.6)

Marital status, single

3078 (34.6)

Living arrangement, living alone

1287 (14.4)

Current alcohol drinking

Covariates
All covariates were obtained from the baseline survey.
Based on previous studies,8,12 19 variables were consideredpotential confounding factors that may correlate with social
participation and incident disability or mortality. Sociodemographic characteristics included age, sex, annual equivalent income, educational attainment, marital status, andliving arrangement. Health conditions included current
alcohol drinking or smoking status, self-rated health, bodymass index, instrumental activities of daily living (IADL)
disability, and chronic diseases such as hypertension, heartdisease, stroke, diabetes, cancer, respiratory disease, andarthritis. We also included the social and physical environment because these factors influence social participation
among the frail.18 The social environment includes social
support (emotional and instrumental) and the frequency of
meeting friends. The physical environment refers to theenvironment within 1 km of a participant's home, such as“parks or footpaths suitable for exercise or walking,” “shops
or facilities that sell fresh fruits and vegetables,” houses or
facilities that can easily be accessed,” “locations that makewalking difficult, such as hills or staircases,” and “roads orcrossroads with a significant risk of traffic accidents.” Allvariables were categorized as shown in Table 1.

Statistical analysis
First, descriptive analyses were performed to characterizebaseline characteristics. Second, a Cox proportional hazard

Current

2501 (28.0)

Past

470 (5.3)

Never5976 (66.8)

Current smoking
Current

1073 (12.6)

Past

2495 (29.2)

Never4972 (58.2)

Self-rated health, not good3814 (42.4)

Body mass index
Low (<18.5)

1100 (12.1)

Middle (18.5–24.9)

5899 (64.9)

High (≥25)
IADL disability, yes

2091 (23.0)5358 (59.4)

Chronic diseases
Hypertension

3928 (50.2)

Heart disease

1539 (19.7)

Stroke164 (2.1)

Diabetes

1380 (17.6)

Cancer558 (7.1)

Respiratory disease557 (7.1)

Arthritis

1756 (22.5)

Abbreviation: IADL, instrumental activities of daily living.

model was developed to compute the multivariateadjusted incident disability and mortality risk. Hazard
ratios (HR) and 95% confidence intervals (CI) of incident
disability and mortality for 6 years were calculated. In themodel of incident disability, a competing risk model wasused. We used Fine and Gray's model to account for

15325415, 0, Downloaded from https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/jgs.18269 by Cochrane Japan, Wiley Online Library on [07/02/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

4

mortality as a competing risk. Social participation was categorized into three types. For example, in the case of thehobby group, we assessed non-participation in any group(reference category), participation in a hobby group, andthose who do not participate in hobby groups but participate in other community activities. We used the Bonferroni
correction to account for multiple comparisons.
To address potential bias due to missing data, we
performed multiple imputations using the multivariate
normal regression method, assuming that the data were
missing at random. Social participation was missing in
19.4% (hobby group) to 27.3% (industry) of the participants according to the groups. Covariates were missing in
2.1% (living arrangement) to 23.7% (chronic diseases) of
the participants, according to covariates. Other missing
variables were less than 10%. We created 20 imputed
datasets and combined the effect estimates using Rubin'srule.30 The numbers and proportions of missing variables
are shown in Table S1.
We conducted three sensitivity analyses. First, to evaluate the robustness of the estimated associations withunmeasured confounders, we calculated E-values for eachexposure-outcome association.31 E-values quantify the minimum strength required for the association of an unmeasured confounder with both the exposure and outcome,above and beyond the adjusted covariates on the risk ratio
scale, to explain the observed association. Second, to reduce
the possibility of reverse causation (i.e., short follow-up time
resulting in incident disability or mortality with or withoutsocial participation), we excluded the participants with incident disability or mortality within the first two-year followup. Third, to account for the possibility of different effects
on incident disability and mortality depending on the frequency of social participation, we analyzed six types ofsocial participation, excluding paid work, by frequency(≥1 day/month and ≥1 day/week). All analyses were performed using STATA MP 16.1 (Stata Corp, College Station,
TX, USA).

RESULTSWe analyzed data from 9090 frail older adults. The proportion of women was 55.1%, and the mean age (SD) was
76.0 (6.6) years. The mean follow-up period (maximum)
for incident disability and mortality was 5.0 (6.4) and 5.4(6.6) years, respectively. Of the participants, mortality
occurred in 1770 (19.5%) participants and disability
occurred in 1753 (19.2%) of the participants.
Table 1 shows the basic characteristics of participantsin the baseline survey. Approximately half of the participants were in the low-income and low-education groups
and
had
IADL
disability
andhypertension.

5

T A B L E 2 Characteristics of the social and physicalenvironment at baseline survey.
Characteristics

Total (N = 9090)

Social support, available
Emotional support

8011 (90.3)

Instrumental support

8255 (92.4)

Frequency of meeting friends
Almost daily

767 (8.7)

2–3 times/week

1562 (17.8)

About once/week

1378 (15.7)

1–2 times/month

1863 (21.3)

A few times a year or less3197 (36.5)

Parks or footpaths suitable for exercise or walking
Exists5705 (63.9)

Does not exist

2795 (31.3)

Unknown

435 (4.9)

Shops or facilities that sell fresh fruits and vegetables
Exists6034 (67.5)

Does not exist

2725 (30.5)

Unknown

185 (2.1)

Houses or facilities you can easily visit
Exists2603 (29.1)

Does not exist

5402 (60.5)

Unknown

925 (10.4)

Locations that make walking difficult, such as hills or steps
Exists3672 (41.0)

Does not exist

4930 (55.1)

Unknown

351 (3.9)

Roads or crossroads with a great risk of traffic accidents
Exists6170 (69.0)

Does not exist

2402 (26.9)

Unknown

365 (4.1)

The percentage of IADL disability by type of social participation was as follows: sports groups or clubs (73.7%), volunteer (72.4%), hobby groups (71.6%), neighborhood
communities (67.9%), industries (67.6%), senior citizens'clubs (61.4%), paid work (59.5%), not any participation(46.9%). Table 2 shows the characteristics of the social andphysical environment at the baseline survey. Most people
received social support (emotional and instrumental support). Regarding the physical environment, approximately
half of the participants answered as follows: parks or footpaths were suitable for exercise or walking, there wereshops or facilities that sold fresh fruits and vegetables, andthere were roads or crossroads with great risk of traffic
accidents.

15325415, 0, Downloaded from https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/jgs.18269 by Cochrane Japan, Wiley Online Library on [07/02/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

SOCIAL PARTICIPATION, DISABILITY, AND MORTALITYABE ET AL.

F I G U R E 1 Bar graph showing the
proportions of participants who
participate in each organization as a few
times a year or more.

F I G U R E 2 Hazard ratios and 95%
confidence intervals of Cox regression
analysis for social participation and riskof incident disability (A) and mortality(B). Reference, no participation. All
models were adjusted for age, sex,
income, education, marital status, living
arrangement, alcohol, smoking, selfrated health, body mass index, theinstrumental activity of daily living,
chronic diseases, social support,frequency of meeting friends, and theexistence of parks, shops, houses,
locations that make walking difficult,and roads. HR, hazard ratio; CI,
confidence interval. *p < 0.05 before
Bonferroni correction; **p < 0.01
before Bonferroni correction; ***p < 0.05
after Bonferroni correction (the p-value
cutoff for Bonferroni correction isp = 0.05/7 outcomes = p < 0.0071).

15325415, 0, Downloaded from https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/jgs.18269 by Cochrane Japan, Wiley Online Library on [07/02/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

6

Figure 1 shows the proportions of participation ineach type of social organization. The organization withthe highest proportion of participants was neighborhood
communities (28.7%). Additionally, the proportion of participation in neighborhood communities and hobby
groups was more than 20%.
Figure 2 shows the association between social participation and incident disability and mortality. In comparison to
non-participation in any group, participation in hobby
groups (HR = 0.74; 95% CI = 0.61–0.90) and sports groups
or clubs (HR = 0.72; 95% CI = 0.58–0.88) were significantly
associated with a lower incidence of disability. On the other
hand, hobby groups (HR = 0.68; 95% CI = 0.56–0.83),
sports groups or clubs (HR = 0.71; 95% CI = 0.57–0.88),
senior citizens' clubs (HR = 0.75; 95% CI = 0.61–0.90),
and volunteers (HR = 0.69; 95% CI = 0.54–0.88) were significantly associated with a lower incidence of mortality.
These associations remained below the p = 0.05 thresholdafter accounting for multiple comparisons via Bonferroni
correction.
In the sensitivity analyses, we calculated E-values toevaluate the robustness of the observed associations
between social participation and subsequent incident disability and mortality among frail older adults to unmeasured confounders (Table S2, S3). For example, to fully
explain the observed association between participation in
hobbies and certification of incident disabilities, unmeasured confounders had to be associated with subsequent
incident disability, with a risk ratio of 1.77 each in participation in hobbies. A 1.36-fold risk ratio was required toshift the CI to include the null value. We also analyzed
the risks of outcomes while excluding data obtained
within two years of follow-up (Table S4). Excluding participants' data obtained within two years of follow-up,
incident disability occurred in 881 (9.7%) of the participants, and mortality occurred in 533 (5.9%). There wasno significant association between incident disability andthe hobby and sports or club groups, but point estimation
was almost at the same level, as shown in Figure 2. There
was a significant association between mortality and eachsocial participation group (Figure 2). In addition, for thesix types of social participation, excluding paid work, we
analyzed the frequency of participation by dividing it into
once a month or more and once a week or more
(Table S5, S6). The overall trend was for HR to decreaseas the frequency of participation increased, but thechange was slight.

DISC USS I ON
To our knowledge, this is the first study to examine theassociation of various social participation groups with the7

incidence of disability and mortality among frail older
adults. We found that social participation compared to
non-participation in any social group among frail older
adults was associated with a lower risk of incident disability and mortality. Sports or club and hobby groups
were protective against both incident disability and mortality, while other types of social participation were protective against mortality. These results, after adjusting forall 27 observable confounding factors, confirm therobustness of the association between social participationand incident disability and mortality among frail older
adults.
Previous studies among community-dwelling older
adults have shown that sports or clubs8,12,13 and hobby
groups8,12–14,27 were associated with low-incidence disability. The present study, which focused on frail older adults,
had findings that were similar to these previous studies.
Furthermore, all seven types of social participationassessed in this study were associated with a reduced riskof subsequent mortality. The results from this study, similar to the findings of previous studies,13,32,33 were obtained
based on assessments that focused on frail older adults.
Frail older adults have smaller social networks,
receive less social support, and are more isolated thanthat observed in the non-frail.34 A chronic health condition may contribute to social isolation or lonelinessby interfering with the quality, quantity, or structureof relationships or by worsening pathophysiologicalprocesses,35 and are further associated with lower participation in social activities.36 This study showed thatparticipation in community activities may contribute to
reducing the risk of subsequent disability and mortality.
Participation in an exercise program for health may leadto reductions in social isolation or loneliness due to thesocial nature of the program rather than the exercise
itself.35 A study suggested that community activities andconnections with other people may promote outings,
which in turn may lead to the maintenance of daily life
functions. Although the potential pathways are still
unclear, better social relationships, obtaining formal/
informal social support, and social ties may be associated with positive health behaviors.37
Although it has been shown that frail older adults haveincreased healthcare costs compared to healthy older
adults,38 this evidence from frailty studies has not yet been
fully translated into clinical practice and healthcare
policy-making.39 To meet the needs of a rapidly aging society, policymakers and healthcare providers need toencourage equal social participation for both healthy andfrail older adults and to provide regular opportunities forsocial participation. This may help prevent further progression from frailty to incident disability and mortality, as
well as optimize social security expenditures.

15325415, 0, Downloaded from https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/jgs.18269 by Cochrane Japan, Wiley Online Library on [07/02/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

SOCIAL PARTICIPATION, DISABILITY, AND MORTALITYThere are some limitations in this study. First,
because this is an observational study, the effect of selection bias on the results cannot be eliminated. We used
E-values to estimate the extent to which observed associations were influenced by unmeasured confounders andsought to minimize the impact of selection bias as muchas possible. We used E-values to confirm that the results
are robust. Second, we did not assess other forms of participation except social participation. In this study, social
participation was defined as participation in community
organizations. However, the frequency of meeting withfriends was considered a confounding factor affecting
both social participation and outcomes and was includedin the analysis, but the results were consistent. Third,
because we analyzed the association of social participation at baseline, we were unable to account for the effectof those who stopped social participation during thefollow-up period. A previous study reported that sustained social participation may be more strongly associated with fewer depressive symptoms.40 Thus, the resultsof this study may have underestimated the effects ofsocial participation. Further studies should consider thedifference between the effects of sustained and temporarysocial participation. Fourth, the details of social participation activities are unknown. For example, the types ofhobbies (go, shogi, handicrafts, etc.) or sports (golf, walking, tennis, etc.) they participated in were unknown. In
addition, the details of the paid work (what kind of work
was done, part-time or full-time) were unknown. Previous studies focusing on the type of sport have reported
that subjective sense of health, frequency of laughter, andtheir association with depression varies according to thetype of sports activities.41 Finally, the generalizability of
the results is limited by the fact that the study focused onJapanese older adults.
In conclusion, the results suggest that the lower riskof incident disability and mortality due to social participation is not only limited to healthy older adults but also
occurs in frail older adults who were at higher risk ofincident disability and mortality. In addition, the results
suggest that all seven types of social participation examined in this study can lower the risk of subsequent disability and mortality. For both healthy and frail older
adults, social participation is important in health policy
to prevent future disability and mortality.
A U T H O R C ON T R I B U T I O NS
All authors (1) made substantial contributions to thestudy concept or the data analysis or interpretation;(2) drafted the manuscript or revised it critically for theimportant intellectual concept; (3) approved the final version of the manuscript to be published; and (4) agreed tobe accountable for all aspects of the work.

ABE ET AL.

ACKNOWLEDGMENTS
The authors would like to thank Editage (www.editage.
com) for English language editing.
F U N D I N G IN F O R M A T I O NThis study used data from JAGES (the Japan Gerontological Evaluation Study). This study was supported by
JSPS (Japan Society for the Promotion of Science)
KAKENHI Grant Number (JP15H01972, 19 K20909,
and 20H00557), Health Labour Sciences Research
Grant (H28-Choju-Ippan-002,19FA1012, 19FA2001,
and 21GA0101), Japan Agency for Medical Research andDevelopment (AMED) (JP18dk0110027, JP18ls0110002,
JP18le0110009, JP20dk0110034, JP21lk0310073, andJP21dk0110037), Open Innovation Platform with Enterprises, Research Institute and Academia (OPERA,JPMJOP1831) from the Japan Science and Technology(JST), a grant from Innovative Research Program on
Suicide Countermeasures (1–4), a grant from Sasakawa
Sports Foundation, a grant from Japan Health Promotion &Fitness Foundation, a grant from Chiba Foundation for
Health Promotion & Disease Prevention, the 8020 Research
Grant for fiscal 2019 from the 8020 Promotion Foundation(adopted number: 19-2-06), grants from Meiji Yasuda
Life Foundation of Health and Welfare and the Research
Funding for Longevity Sciences from National Center for
Geriatrics and Gerontology (29-42, 30-22, 20-19, 21-20).
CONFLICT OF INTEREST
The authors have declared no conflicts of interest in thisarticle.
SP ONS O R 'S RO LE
None.
ORCID
Takahiro Hayashi https://orcid.org/0000-0001-68874378
Genmei Iizuka https://orcid.org/0000-0003-0047-8664
RE FER EN CES
1. WHO. Ageing and health. World Health Organization (online).
Accessed August 16, 2022. Available at: https://www.who.int/
news-room/fact-sheets/detail/ageing-and-health
2. Hoogendijk EO, Afilalo J, Ensrud KE, Kowal P, Onder G,Fried LP. Frailty: implications for clinical practice and publichealth. Lancet. 2019;394:1365-1375.
3. Shinkai S, Yoshida H, Taniguchi Y, et al. Public healthapproach to preventing frailty in the community and its
effect on healthy aging in Japan. Geriatr Gerontol Int. 2016;
16:87-97.
4. Fried LP, Tangen CM, Walston J, et al. Frailty in older adults:
evidence for a phenotype. J Gerontol A Biol Sci Med Sci. 2001;
56:M146-M156.

15325415, 0, Downloaded from https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/jgs.18269 by Cochrane Japan, Wiley Online Library on [07/02/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

8

5. Yamada M, Arai H. Predictive value of frailty scores for healthy
life expectancy in community-dwelling older Japanese adults.
J Am Med Dir Assoc. 2015;16:1002.e7-1002.e11.
6. Yamada M, Arai H. Self-management group exercise extends
healthy life expectancy in frail community-dwelling older
adults. Int J Environ Res Public Health. 2017;14:531.
7. Vermeiren S, Vella-Azzopardi R, Beckwée D, et al. Frailty andthe prediction of negative health outcomes: a meta-analysis.
J Am Med Dir Assoc. 2016;17:e1-1163.e17.
8. Kanamori S, Kai Y, Aida J, et al. Social participation and theprevention of functional disability in older Japanese: the
JAGES cohort study. PLoS One. 2014;9:e99638.
9. Hikichi H, Kondo N, Kondo K, Aida J, Takeda T, Kawachi I.
Effect of a community intervention programme promotingsocial interactions on functional disability prevention for older
adults: propensity score matching and instrumental variable
analyses, JAGES Taketoyo study. J Epidemiol Community
Health. 2015;69:905-910.
10. Nemoto Y, Saito T, Kanamori S, et al. An additive effect ofleading role in the organization between social participationand dementia onset among Japanese older adults: the AGES
cohort study. BMC Geriatr. 2017;17:297.
11. Hikichi H, Kondo K, Takeda T, Kawachi I. Social interaction
and cognitive decline: results of a 7-year community intervention. Alzheimers Dement (N Y). 2017;3:23-32.
12. Ide K, Tsuji T, Kanamori S, Jeong S, Nagamine Y, Kondo K.
Social participation and functional decline: a comparative
study of rural and urban older people, using Japan gerontological evaluation study longitudinal data. Int J Environ Res Public
Health. 2020;17:617.
13. Takahashi S, Ojima T, Kondo K, Shimizu S, Fukuhara S,
Yamamoto Y. Social participation and the combination of futureneeds for long-term care and mortality among older Japanesepeople: a prospective cohort study from the Aichi Gerontologicalevaluation study (AGES). BMJ Open. 2019;9:e030500.
14. Okura M, Ogita M, Yamamoto M, Nakai T, Numata T, Arai H.
Community activities predict disability and mortality incommunity-dwelling older adults. Geriatr Gerontol Int. 2018;18:1114-1124.
15. Levasseur M, Richard L, Gauvin L, Raymond E. Inventory andanalysis of definitions of social participation found in the aging
literature: proposed taxonomy of social activities. Soc Sci Med.
2010;71:2141-2149.
16. Xie B, Ma C. Effect of social participation on the developmentof physical frailty: do type, frequency and diversity matter?
Maturitas. 2021;151:48-54.
17. Dury S, Stas L, Switsers L, et al. Gender-related differences in
the relationship between social and activity participation andhealth and subjective well-being in later life. Soc Sci Med. 2021;
270:113668.
18. Duppen D, Lambotte D, Dury S, et al. Social participation in
the daily lives of frail older adults: types of participation andinfluencing factors. J Gerontol B Psychol Sci Soc Sci. 2020;75:
2062-2071.
19. Kondo K. Progress in aging epidemiology in Japan: the JAGES
project. J Epidemiol. 2016;26:331-336.
20. Advancing universal health coverage through knowledge translation for healthy ageing: Lessons learnt from the Japan gerontological evaluation study. Kondo K, Rosenberg M, World

9

Health Organization (online). Accessed August 16, 2022. Available at: https://apps.who.int/iris/handle/10665/279010
21. Arai H, Satake S. English translation of the Kihon Checklist.
Geriatr Gerontol Int. 2015;15:518-519.
22. Satake S, Senda K, Hong YJ, et al. Validity of the Kihon Checklist
for assessing frailty status. Geriatr Gerontol Int. 2016;16:709-715.
23. Satake S, Shimokata H, Senda K, Kondo I, Toba K. Validity of
Total Kihon Checklist score for predicting the incidence of
3-year dependency and mortality in a community-dwellingolder population. J Am Med Dir Assoc. 2017;18:552.e1-552.e6.
24. Noguchi T, Murata C, Hayashi T, et al. Association between
community-level social capital and frailty onset among older
adults: a multilevel longitudinal study from the Japan Gerontological evaluation study (JAGES). J Epidemiol Community
Health. 2021;76:182-189.
25. Sewo Sampaio PY, Sampaio RA, Yamada M, Arai H. Systematic review of the Kihon Checklist: is it a reliable assessment offrailty? Geriatr Gerontol Int. 2016;16:893-902.
26. Sato K, Ikeda T, Watanabe R, Kondo N, Kawachi I, Kondo K.
Intensity of community-based programs by long-term careinsurers and the likelihood of frailty: multilevel analysis ofolder Japanese adults. Soc Sci Med. 2020;245:112701.
27. Otsuka T, Tomata Y, Zhang S, et al. Association between social
participation and incident risk of functional disability in elderly
Japanese: the Ohsaki cohort 2006. J Psychosom Res. 2018;111:36-41.
28. Tsutsui T, Muramatsu N. Care-needs certification in the longterm care insurance system of Japan. J Am Geriatr Soc. 2005;53(3):522-527.
29. Ukawa S, Tamakoshi A, Okada Y, et al. Social participation
patterns and the incidence of functional disability: the Japan
Gerontological evaluation study. Geriatr Gerontol Int. 2020;20:765-772.
30. Rubin DB. Multiple imputation after 18+ years. J Am Stat
Assoc. 1996;91:473-489.
31. VanderWeele TJ, Ding P. Sensitivity analysis in observational
research: introducing the E-value. Ann Intern Med. 2017;167:
268-274.
32. Aida J, Kondo K, Hirai H, et al. Assessing the association between
all-cause mortality and multiple aspects of individual social capital among the older Japanese. BMC Public Health. 2011;11:499.
33. Okamoto S, Okamura T, Komamura K. Employment andhealth after retirement in Japanese men. Bull World HealthOrgan. 2018;96:826-833.
34. Hoogendijk EO, Suanet B, Dent E, Deeg DJ, Aartsen MJ.
Adverse effects of frailty on social functioning in older adults:
results from the longitudinal aging study Amsterdam. Maturitas. 2016;83:45-50.
35. Social Isolation and Loneliness in Older Adults. National Academies of Sciences E, and Medicine (online). Accessed Jan 4, 2023.
Available at: https://www.ncbi.nlm.nih.gov/pubmed/32510896
36. Cantarero-Prieto D, Pascual-Saez M, Blazquez-Fernandez C. Social
isolation and multiple chronic diseases after age 50: a European
macro-regional analysis. PLoS One. 2018;13(10):e0205062.
37. Umberson D, Crosnoe R, Reczek C. Social relationships andhealth behavior across life course. Annu Rev Sociol. 2010;36:
139-157.
38. Chi J, Chen F, Zhang J, et al. Impacts of frailty on health carecosts among community-dwelling older adults: a meta-analysis
of cohort studies. Arch Gerontol Geriatr. 2021;94:104344.

15325415, 0, Downloaded from https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/jgs.18269 by Cochrane Japan, Wiley Online Library on [07/02/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

SOCIAL PARTICIPATION, DISABILITY, AND MORTALITY

39. Kojima G, Liljas AEM, Iliffe S. Frailty syndrome: implications
and challenges for health care policy. Risk Manag Healthc Policy. 2019;12:23-30.
40. Shiba K, Torres J, Daoud A, et al. Estimating the impact of sustained social participation on depressive symptoms in older
adults. Epidemiology. 2021;32:886-895.
41. Tsuji T, Kanamori S, Saito M, Watanabe R, Miyaguni Y,
Kondo K. Specific types of sports and exercise group participation and socio-psychological health in older people. J Sports
Sci. 2020;38:422-429.

S UP PO RT ING IN FOR MAT ION
Additional supporting information can be found online
in the Supporting Information section at the end of thisarticle.
Table S1. Numbers and proportions of missing variablesof the participants in 2020 (Total N = 9090).
Table S2. Hazard ratios and 95% confidence intervals of
Cox regression analysis and E-value for the risks of incident disability.

ABE ET AL.

Table S3. Hazard ratios and 95% confidence intervals of
Cox regression analysis and E-value for the risks of incident mortality.
Table S4. Risks of incident disability and mortality infrail older adults excluding data obtained within the firsttwo years of follow-up.
Table S5. Risks of incident disability and mortality infrail older adults according to the frequency of social participation (≥1 day/month).
Table S6. Risks of incident disability and mortality infrail older adults according to the frequency of social participation (≥1 day/week).
How to cite this article: Abe N, Ide K,
Watanabe R, Hayashi T, Iizuka G, Kondo K. Social
participation and incident disability and mortality
among frail older adults: A JAGES longitudinal
study. J Am Geriatr Soc. 2023;1‐10. doi:10.1111/jgs.
18269

15325415, 0, Downloaded from https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/jgs.18269 by Cochrane Japan, Wiley Online Library on [07/02/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

10