Open access

Research

Masashige Saito,1,2 Jun Aida,3 Naoki Kondo,4 Junko Saito,4 Hirotaka Kato,5Yasuhiro Ota,6 Airi Amemiya,4 Katsunori Kondo7,8

To cite: Saito M, Aida J,
Kondo N, et al. Reduced
long-term care cost bysocial participation amongolder Japanese adults:
a prospective follow-up
study in JAGES. BMJ Open
2019;9:e024439. doi:10.1136/
bmjopen-2018-024439►► Prepublication history andadditional material for thispaper are available online. Toview these files, please visit
the journal online (http://​dx.​doi.​
org/​10.​1136/​bmjopen-​2018-​
024439).

Received 25 May 2018
Revised 29 January 2019
Accepted 30 January 2019

© Author(s) (or theiremployer(s)) 2019. Re-use
permitted under CC BY-NC. No
commercial re-use. See rights
and permissions. Published by
BMJ.
For numbered affiliations see
end of article.
Correspondence to
Dr Masashige Saito;​masa-​s@n​ -​fukushi.​ac.​jp

Abstract
Objectives Reducing costs related to functional
disabilities and long-term care (LTC) is necessary in ageing
societies. We evaluated the differences in the cumulative
cost of public LTC insurance (LTCI) services by social
participation.
Design Prospective observational study.
Setting Our baseline survey was conducted in March
2006 among people aged 65 or older who were noteligible for public LTCI benefits and were selected using
a complete enumeration in Tokoname City, Japan. We
followed up with their LTC services costs over a periodof 11 years. Social participation was assessed by thefrequency of participation in clubs for hobbies, sports or
volunteering. We adopted a classical linear regression
analysis and an inverse probability weighting (IPW), withmultiple imputation of missing values.
Participants Functionally independent 5377 older adults.
Primary outcome measures The cumulative cost of
public LTCI services for 11 years.
Results Even when adjusting for the confounding
variables, social participation at the baseline wasnegatively associated with the cumulative cost of LTCI
services. The IPW model showed that in respondents who
participated in hobby activities once a week or more,
the cumulative cost of LTCI services for 11 years was
lower, approximately US$3500 per person, in comparison
to non-participants. Similarly, that in respondents
who participated in sports group or clubs was lower,
approximately US$6000 than non-participants.
Conclusions Older adults’ participation in community
organisations may help reduce future LTC costs. Promoting
participation opportunities in the community could ensure
the financial stability of LTCI services.

Introduction
Across the globe, costs related to functional
disabilities and long-term care (LTC) are
rapidly increasing in societies with ageing populations. Expenses are greater among those withmore severe impairments.1 In Japan, in oneof the countries experiencing the highest rateof ageing, the proportion of older people
is currently 27.3% and is predicted to reachStrengths and limitations of this study►► To our knowledge, this is the first to demonstratethat social participations among older adults might
help lower subsequent long-term care insurance(LTCI) costs.
►► Our findings are based on an 11-year prospective
observational study using public LTCI receipt data
in Japan.
►► Selection bias might have occurred because of the
53% response rate to the baseline survey.
►► The measurements of social participation rely on
self-reported questionnaire.

around 40% by 2065.2 Under these circumstances, the costs for LTC insurance (LTCI) are
expected to rise from US$100 billion in 2016 to
US$210 billion by 2025.
Lowering these costs requires building asustainable and healthy ageing society whichmeans developing and maintaining thefunctional ability that enables well-being inolder age. The Japanese government implemented a public nursing care insurance lawthat includes an LTC prevention policy.3 For
this policy, a population approach as primaryprevention was proposed rather than a highrisk one which was grounded in risk screening
based on intervention targeting. Promotingsocial participation is considered an effective intervention regarding the population
approach, which focuses on the entire groupof older adults in a community.
Although social participation is an ambiguous concept, Bukov distinguished three
types of participation: collective, productive
and political.4 In this paper, we focused on
involvement in collective activities in formal
and informal societal groups at local community. Social participation helps maintain social
networks, support and roles, raises self-esteem
and self-efficacy and facilitates access to various

Saito M, et al. BMJ Open 2019;9:e024439. doi:10.1136/bmjopen-2018-024439

1

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Reduced long-term care cost by social
participation among older Japanese
adults: a prospective follow-up study
in JAGES

Open access

Methods
Study design
The Japan Gerontological Evaluation Study conducted aself-administered questionnaire in March 2006 as a baseline;
5483 respondents who were 65 years or older, physically andcognitively independent and not eligible for public LTCI
benefits were selected using a complete enumeration; they
live in the city of Tokoname in Aichi Prefecture (response
rate=53.4%: 5483/10 274). In addition, our subjects weremore healthy or active older adults at baseline, because Japanese LTCI certifies the people included mild care needs,
not only severe care level. Afterwards, we obtained receipt
data on LTCI benefits over a period of 11 years after thebaseline survey from government database of public LTCI.
After eliminating respondents who lacked information on
sex and age (n=42), who had moved out of their residence(n=38) and who had been certified for LTCI before thebaseline survey (n=26), 5377 respondents were linked to the
LTCI receipt data set (figure 1).
Measurements
Outcome variables: the costs of LTCI services
Primary outcome variable is the cumulative cost of LTCI
services at follow-up period. We obtained the LTC costs
of insured services across 44 points every 3 months (April,
2

Figure 1 Flow chart of respondent selection. LTCI, longterm care insurance.

July, October, January) over a period of 11 years. We
summed them up after tripling these monthly costs inorder to calculate an approximate value of the overall costfor the follow-up period. We used the currency exchange
rate of JP¥100 to US$1. As closely related variable, we
calculated the number of months which was eligible for
LTCI benefit across the whole population, from care level
5 which signifies the highest level of requirement for LTC
to any care or support level.
In addition, Japanese LTCI operates based on social
insurance principles. Only services are provided, not cash
allowances, and recipients can choose their services andproviders.24 The receipt data includes information about
using insured services such as home visits, day, short stay,residential or in-facility services. The data do not include
costs, which are not covered by insurance (such as food,housing and diaper expenses). In general, 10% of thesecosts are copayments (the municipality, which acts as aninsurer, pays 90%), although there is a upper limit to
the amount of monthly insurance benefits, which differs
depending on the needed level of care. People with certifications for LTC and who need (levels 1 to 5) or require
support (levels 1 or 2) can use LTCI services. Those
higher levels of care can use more LTCI services throughinsurance coverage. The cumulative cost of such care in
the following cases is zero: deceased individuals who did
not have functional disabilities, respondents who did nothave proper certification and non-service users.
Explanatory variables: social participation
As mentioned above, social participation is an ambiguous
concept. The indicator of social participation was taken
Saito M, et al. BMJ Open 2019;9:e024439. doi:10.1136/bmjopen-2018-024439

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kinds of information. Several international systematic
reviews and meta-analyses have reported on the physical,
psychological and social benefits of social participation
among older people.5–10 For instance, meta-analysis across
148 articles mentioned active engagement in social activities could reduce risk for mortality. In particular, previous
observational studies in Japan also found that collective
social participation activities such as volunteering, sports
clubs and hobbies among older adults lowered the risk ofdeveloping depressive symptoms,11–13 the incidence of functional disabilities,14–16 cognitive decline or dementia,17 18
falls19 and immature death.20–23
We hypothesise that if social participation extends healthy
life expectancy and reduces the time spent in intensive
nursing care, then the cumulative cost of LTCI services
might be lower among the participants; however, to ourknowledge, there is no evidence that social participation
lessens it. In addition, Japanese LTCI services are provided
mainly when people aged 65 and over come to requirecare or support, based on investigation for certificationand doctor’s written opinion. The cost of LTCI services is
one of the most important issues for the public sector as
an insurer. The evidence for contributing to cost-saving
has been useful for recent intervention financing schemesthat provide economic incentives to service providers, forinstance, social impact bonds. In this paper, using data froma follow-up study that took place over a period of 11 years
and tracked older Japanese adults, we assessed the differences of the duration period of requiring care level and of
the cumulative cost of LTCI services by frequency of social
participation in baseline survey.

Open accessCovariates
Demographic variables included sex, age, educational
attainment, equivalent income (US$), marital status andliving situation at the baseline survey. It is well known thatthese are basic variables as social determinants of health.
Age was a continuous variable (73.4±6.2). Years of education was categorised as <6, 6–9, 10–12 and 13+. We equalised
household income by the square root of the numbers andclassified it as <20.0, 20.0–39.9 and 40.0+ thousand USD.
Marital status consisted of married, widowed, divorced andnever married. Living situation was categorised as living
alone, with one’s spouse only, with a child or with otherssuch as grandchildren, siblings and relatives.
In order to account for the health status at the baseline, the presence of disease or impairment and selfrated health were considered. The presence of disease or
impairment was based on self-reported medical condition(no illness, having illness but need no treatment, having
illness but discontinued treatment and receiving sometreatment). We dichotomised it, that is, no illness or not.
We assessed self-rated health using four categories: excellent, good, fair and poor.
Statistical analysis
After calculating the descriptive statistics, we conductedfour regression analyses. First, we adopted a classicallinear regression (ordinary linear squares [OLS]) model,
controlling covariates at baseline survey. We handled themissing value in each control variable as a dummy variable. Second, as one of robustness check, we predicted
the marginal effects, adopting a generalised linear model(GLM)30 with Gamma distribution, as well as the log
link and robust variance estimator, because our dependent variable (the cumulative cost of LTCI services) is
not normally distributed. Next, we performed a multiple
imputation technique by chained equations underthe missing at random assumption, which means there
might be systematic differences between the missing andobserved values. We created 20 imputed data sets. Usingeach data set, we first estimated the OLS model with the
Saito M, et al. BMJ Open 2019;9:e024439. doi:10.1136/bmjopen-2018-024439

robust variance estimator. Finally, in order to estimate
the potential outcomes after conditioning on the covariates, we adopted the inverse probability weighting (IPW)model31 32 using the imputed data sets. We calculated thegeneralised propensity scores using multinomial regression analysis, employing all previously listed covariates. For
reference, we only examined the same model among thedeceased, who passed away during the follow-up period.
The LTCI costs for the deceased indicates the ‘lifetimecost’ of LTCI because they did not use LTCI services atthe baseline. We performed analyses using STATA V.15.1(STATA Corp LP, College Station, Texas, USA).
Patient and public involvement
No patient or the public was involved in the developmentof research question and design of this study. The resultsof this research will be disseminated to stakeholders
such as local and central health government after being
published in a scientific journal.

Results
Table 1 shows the characteristics of the respondents;
the mean age at the baseline was 73.4; 52.0% of the
respondents were men. Out of this amount, 30.4% had
used LTCI services at least once, and 28.4% passed away
during the follow-up period. The average of the cumulative cost of LTCI services during the follow-up period was
US$13.7 thousand. The distribution of that was skewed
right. There were significant differences in the average
duration for the level of care required for social participation across the whole population during the follow-up
period (table 2). Non-participants in groups for hobbies,
sports and volunteering had a longer duration of certification for LTC at all care levels. For example, among
participants who took part in the group for hobbies, theaverage duration for non-participants was 14.1 (SD=25.8)
months, whereas that of those who participated ‘once aweek or more’ was 10.6 (SD=21.6) months.
The classical regression model showed that in comparison to non-participants, respondents who participatedin the group for hobbies once a week produced a cost
containment in US$3.6 (95% CI 6.0 to 1.3) thousand,which was lower per person for LTCI cumulative costs
over the 11-year period (table 3). Likewise, participating
in a sports club was also significantly associated with lower
LTCI costs: the category of those who took part ‘once aweek or more’ was US$4.9 (95% CI 6.9 to 2.8) thousandless per person. However, in the volunteer group, only
less frequent participation was associated with lower costs;
for individuals in the category of ‘a few times a year’, thisfigure was US$4.1 (95% CI 7.1 to 1.0) thousand less perperson. When we changed the estimation method to
GLM, and when we adopted OLS after multiple imputation, the major results and trends were similar to theabove, although some point estimations in GLM werehigher in the categories that had a small sample size
(please see online supplementary table S1).
3

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from the Japanese General Social Survey,25 and categorised organisations into following eight types as collective
social participation activities: hobby activities group, sports
group or club, volunteer group, neighbourhood association, senior citizen club/firefighting team, religious group,
political organisation or group, industrial or trade association and citizen or consumer group. We focused on thethree groups/organisations previously identified as being
associated with lower risks for functional disabilities: hobby
activities group,17 23 sports group or club15 23 and volunteer
group.26 27 According to principal components analysis,
these community activities were categorised to horizontalorganisations.28 29 Respondents were asked how often they
took part in these activities. We categorised them to the four
frequencies, respectively: never, a few times a year, once or
twice a month and once a week or more.

Open access

Total

Cumulative cost of LTCI services
in11 years (US$1000)*%

Mean±SDP valueSex† Male52.0

7.7±24.8 Female48.0

18.7±44.8<0.001Age† (Mean±SD)(73.4±6.2) 65–7461.3

6.3±25.2 75–8433.3

23.0±47.2

 85+

5.4

39.1±56.4<0.001

Disease and/or impairment†* None27.2

10.9±35.5 Presence *64.6

14.3±37.8 Missing

8.3

17.7±39.7

 <6

2.7

30.7±57.6

 6–9

41.9

12.4±34.9 10–1224.8

13.1±37.2

 13+

32.2

11.1±33.3 Missing

10.7

23.2±48.8

0.001

Years of education†<0.001

Equivalent income (US$1000)† <20.0

36.0 20.0–39.927.3

9.5±30.5 40.0+6.8

12.0±35.5 Missing

29.9

19.6±43.6

12.2±36.5<0.001

Marital status† Married

69.2

9.2±29.7 Widowed

21.4

24.8±50.2 Divorced

1.7

11.0±27.9 Never married

2.0

27.4±60.1 Missing

5.7

22.7±45.9 Living alone

10.7

23.8±50.9 With spouse only

36.5

9.6±30.1 With child

22.7

12.9±35.9 With others

25.6

14.6±39.7 Missing

4.6

21.3±41.6<0.001

Living situation†<0.001

Self-rated health† Excellent

6.0

7.9±30.5 good61.7

11.5±34.5 Fair22.5

18.2±43.0 Poor5.1

21.7±45.6 Missing

4.7

18.9±39.9

100.0

13.7±37.4

Total<0.001*A breakdown of proportion was as follows: one=32.1%, two=15.2%,
three=4.2%, four and over=1.9%, unknown=11.2%. These variables are basedon baseline questionnaire survey.
†These variables are based on baseline questionnaire survey.
LTCI, long-term care insurance.

The estimations of IPW showed similar outcomes. In
comparison to non-participants, going to a group for
hobbies once a week or more resulted in a cost that4

was reduced by approximately US$3.5 (95% CI 6.2 to0.8) thousand; for sports clubs, this lowered figure wasapproximately US$6.1 (95% CI 9.3 to 2.8) thousand. The
significant relationship with less frequent participationin the volunteer group disappeared, but the directionof the association and point estimations did not largely
change (the C statistics in these models are shown inonline supplementary table S2).
In addition, in comparison to non-participants, fordeceased individuals during the follow-up period, joininga group for hobbies (once a week+) or sports (once a
week+) led to a reduced cost of approximately US$3.9 to
US$5.7 thousand and US$9.4 to US$11.4 thousand, respectively (please see online supplementary table S3). These
outcomes are preliminary because there were very few analysed subjects (especially the sports and volunteer groups).
Discussions
According to the 11-year prospective cohort study ofhealthy Japanese older adults, compared with non-participants, respondents who took part in hobby groups orsports activities once a week incurred lower costs for LTCI
services (approximately US$3.5 and US$6.1 thousand,respectively, per person), even after demographic variables and health status at baseline were controlled.
These findings are consistent with those of previous
research in which several longitudinal studies have shownthat older adults who participate in social activities havelower risks of disability,33 functional declines34 35 andmobility declines.36 37 Moreover, it has been suggested thatparticipation in hobby groups, sports clubs and volunteer groups might contribute to reducing the incidenceof physical disability risks.15 17 23 26 27 In an intervention
study examining the effect of community salons in Japan,
it was reported that the incidence of physical disability
risks among participants fell by 51% over 5 years38 andthat cognitive disability risks declined by around 30%
over 7 years.39 Several trajectory analyses have shown that
attending leisure activities is related to ‘functional maintenance,’40 while a low frequency of going outside thehome was related to being ‘persistently disabled.’41
This study adds evidence to the current literaturesuggesting that social participation may be effective not only
for preventing functional deterioration but also in terms of
reducing LTC costs. Our findings also illustrate that themore the respondents took part in each type of community
activity, the less time they spent in intensive nursing care.
Although the mechanisms behind the relationship between
collective social participation and LTCI costs are not fully
understood, participating in community activities might
contribute to the promotion of physical activities, the maintenance of social role and social networks and the acquisition of important health-related information. Therefore,
differences in LTCI costs may have arisen due to extensions
to healthy life expectancy or reductions in the periods offunctional disability, rather than restrictions on the useof the required services. Lifetime LTCI costs, which were
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Table 1 Characteristics of respondents

Open access

n

ALL*

Care Lv1+

Care Lv2+

Care Lv3+

Care Lv4+

Care Lv5

Mean (SD)

Mean (SD)

Mean (SD)

Mean (SD)

Mean (SD)

Mean (SD)

Hobby activities group  Never2833

14.1 (25.8)

9.8 (21.4)

7.1 (17.6)

4.0 (12.5)

2.2 (8.5)

0.8 (4.6) A few times a year259

9.0 (19.4)

5.6 (15.7)

3.5 (9.9)

1.8 (6.4)

1.2 (5.3)

0.6 (4.1) Once or twice a month524

10.7 (21.8)

6.1 (16.6)

4.6 (14.4)

2.7 (10.2)

1.6 (7.5)

0.6 (3.7) Once a week +972

10.6 (21.8)

6.2 (16.6)

4.1 (13.2)

2.2 (9.3)

1.0 (6.0)

0.4 (3.0)

p<0.001p<0.001p<0.001p<0.001p=0.019p=0.0263716

13.7 (25.1)

9.3 (20.7)

6.6 (17.0)

3.8 (12.1)

2.1 (8.4)

0.8 (4.6) A few times a year91

7.5 (19.6)

5.6 (18.4)

4.8 (16.5)

2.8 (12.0)

1.2 (5.5)

0.8 (5.0) Once or twice a month125

6.0 (17.3)

3.3 (13.4)

2.7 (12.5)

1.4 (6.9)

0.5 (2.6)

0.2 (1.4) Once a week +572

7.2 (18.1)

3.8 (12.8)

2.4 (9.8)

1.0 (5.4)

0.5 (3.4)

0.1 (1.0)

p<0.001p<0.001p<0.001p<0.001p<0.001p=0.005

Sports group or club  NeverVolunteer group  Never3899

12.9 (24.4)

8.6 (20.0)

6.1 (16.4)

3.5 (11.6)

1.9 (7.9)

0.7 (4.3) A few times a year194

7.1 (17.3)

3.9 (12.8)

2.9 (11.1)

1.6 (8.3)

1.1 (7.7)

0.7 (5.6) Once or twice a month193

9.9 (21.6)

6.1 (17.0)

4.3 (13.3)

2.0 (8.9)

1.1 (7.2)

0.4 (2.7) Once a week +122

6.4 (17.5)

3.9 (12.4)

3.1 (10.9)

1.6 (6.9)

0.8 (3.2)

0.2 (1.5)

p<0.001p<0.001p<0.001p<0.001p=0.019p=0.165*This is including certification for long-term care level from support level one to care level 5.
Unit: month.

estimated among deceased individuals, showed similar
trends. This suggests that postponing the onset of functional disabilities or death did not cause the differences incosts.
On the other hand, for volunteer activities, less frequent(rather than very frequent) participation resulted inlower LTCI costs. In Japan, it has often been mentionedthat a portion of those participating in volunteer activities
shoulder excessive burdens in terms of supporting those
activities, and official Japanese statistics have revealed
that half of older adults preferred volunteer activities that
do not constrain their time.42 Our results also suggest thatbeing forced to take part in volunteer activities, which iscounter to the intended meaning of volunteering, might
not necessarily protect the participant’s health, eventhough participating in and of itself has preventive effects.
It is clear that this study has public health implications.
For example, one systematic review mentioned that most
local and national public health interventions are aimed
at cost saving,43 and our results suggest that promoting
participation in community activities might have a non-ignorable cost-containment effect. More specifically, 21.8%
and 12.7% of the respondents, or about 2240 and 1300
people, in this municipality may have been participatingin hobby or sports groups at least once a week. If thosenumbers were 10% higher (approximately 220 and 130
people), it may have been possible to reduce the cumulative cost of LTCI services by approximately US$780 to
US$800 and US$630 to US$790 thousand, respectively,
Saito M, et al. BMJ Open 2019;9:e024439. doi:10.1136/bmjopen-2018-024439

over an 11-year period. It is important to note thateach activities discussed in this paper are not special
programmes, and that all of them are already common
in Japan. Hence, the additional expenditures to be borneby the public sector would be comparatively minor. It isalso suggested that an accumulation of cost impact analyses might be meaningful in terms of public health andcommunity work research. Furthermore, our findings
might even be an underestimation because less frequent
categories for each type of social participation tend toresult in higher mortality rates.
Our study has several limitations and strengths. First,
due to restricted data accessibility, we could not analyse
medical care costs, which is significant because a previous
study mentioned that medical care and LTC expenditures
have a weak, but negative, relationship.44 However, to thebest of our knowledge, our study is the first to demonstratethat social participations among older adults might help
lower subsequent LTCI costs. Second, we assessed social
participation variables and covariates only at the baseline.
More specifically, our study only analysed healthy older
adults, excluding those with physically and cognitively
disabilities. We also controlled for multiple health dimensions and other covariates by adopting several statisticaltechniques. However, since the baseline survey was basedon a self-reported questionnaire, we cannot deny the possibility of reverse causation. Third, generalisability might belimited by the fact that our study was conducted in one
municipality, even though the proportions of older adults
5

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Table 2 Average duration of care giving at follow-up period by social participation*

Open access

OLS ‡§

IPW with MI ¶††

n

Mean

Coef. (95% CI)

Coef. (95% CI)

Mortality

Hobby activities group  Never

2833

14.6

ref.

ref.

30.8

 A few times a year

259

6.6

−3.2† (−6.7 to 0.2)

−3.5 (−8.1 to 1.2)

28.0

 Once or twice a month

524

10.2

−2.8† (−5.8 to 0.7)

−2.2 (−5.6 to 1.2)

21.7

 Once a week +

972

9.4

−3.6** (−6.0 to −1.3)−3.5* (−6.2 to −0.8)

19.5

3716

13.9

ref.

ref.

29.1

91

9.3

2.5 (−4.9 to 9.9)

1.8 (−5.8 to 9.4)

18.7

Sports group or club  Never A few times a year
 Once or twice a month

125

4.8

−3.3 (−7.6 to 9.4)

−4.2 (−10.7 to 2.3)

16.1

 Once a week +

572

5.2

−4.9*** (−6.9 to −2.8)−6.1*** (−9.3 to −2.8)

18.6  Never

3899

12.7

ref.

ref.

28.4

 A few times a year

194

4.8

−4.1** (−7.1 to −1.0)−3.9 (−9.1 to 1.3)

20.7

 Once or twice a month Once a week +

193
122

10.0
5.9

1.9 (−2.9 to 6.7)
−0.7 (−4.5 to 3.1)

1.5 (−3.8 to 6.7)
−1.4 (−7.9 to 5.1)

12.7
11.5

Volunteer group*p<0.05, **p<0.01, ***p<.001, †p<0.10. Unit: US$1000.
‡Missing values in control variables were included as a dummy variable.
§The result was controlled by sex, age, disease and/or impairment, years of education, equivalent income, marital status, living situation, selfrated health at baseline.
¶Multiple imputation by chained equations was performed using sex, age, disease and/or impairment, years of education, equivalent income,marital status, living situation, self-rated health at baseline (m=20).
††The generalised propensity scores were calculated using multinominal regression analysis using all previously listed potential confounders:sex, age, disease and/or impairment, years of education, equivalent income, marital status, living situation, self-rated health.
IPW, inverse probability weighting; MI, multiple imputation; OLS, ordinal least squares.

and certified LTC levels between the subject area and thenational average are roughly the same. Furthermore, selection bias might have occurred because the response rate
in our baseline survey was not high (53.4%). However,there are important conclusions that can be drawn from ananalysis of merged individual data from this questionnaire
regarding social life and public receipt data as they pertain
to LTC services. Fourth, there might be measurement bias
regarding the actual social participation levels because thedata were derived solely from responses to the self-reported
questionnaire. Although our indicators have often beenused in previous surveys, it is possible that the self-reported
activities do not reflect actual participation levels. To assess
the frequency and role of these groups, future researchshould examine interactions among participating members
using more objective indicators.
Author affiliations
1
Faculty of Social Welfare, Nihon Fukushi University, Chita-gun, Aichi, Japan
2
Center for Well-being and Society, Nihon Fukushi University, Nagoya, Aichi, Japan3
Department of International and Community Oral Health, Tohoku University
Graduate School of Dentistry, Sendai, Miyagi, Japan
4
Department of Health Education and Health Sociology, School of Public Health,
TheUniversity of Tokyo, Bunkyo-ku, Tokyo, Japan
5
Graduate School of Business Administration, Keio University, Yokohama, Kanagawa,Japan
6
QOL 84 Plus Inc., Nagoya, Aichi, Japan
7
Center for Preventive Medical Science, Chiba University, Chuo-ku, Chiba, Japan

6

8

Center for Gerontology and Social Sciences, National Center for Geriatrics andGerontology, Obu, Aichi, Japan

Acknowledgements The authors thank public and private sector staff in thiscommunity and other JAGES group members for their helpful suggestions.
Contributors All authors contributed to the conception and design of this study.
Data collection was primarily conducted by MS, YO and KK. Analyses were
performed by MS and supported by JA, NK, JS and HK. MS prepared the initialmanuscript and JA, NK, JS, HK, AA and KK significantly contributed to revising it. All
authors read and approved the final manuscript.
Funding This study was supported in part by JSPS KAKENHI (16K13443,
18H00953, 18H04071), the Research and Development Grants for Longevity
Science from AMED (Japan Agency for Medical Research and development,
JP18dk0110027, JP18ls0110002, JP18le0110009). The baseline survey data fromthe Aichi Gerontological Evaluation Study (AGES), were conducted by the Center for
Well-being and Society, Nihon Fukushi University as one of their research projects.
This study was supported in part by MEXT-Supported Program for the Strategic
Research Foundation at Private Universities, 2009-2013 and Grant-in-Aid for
Scientific Research (KAKENHI) (23243070, 18390200).
Disclaimer The funders had no role in study design, data collection and analysis,
decision to publish, or preparation of the manuscript. Any credits, analyses,interpretations, conclusions, and views expressed in this paper are those of theauthors, and do not necessarily reflect those of the institutions.
Competing interests None declared.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement Data are not open for public due to ethical concerns.
Data are from the JAGES study whose authors may be contacted at data
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Table 3 Differences of cumulative cost in LTCI services in an 11-year follow-up period by social participation

Open access

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permits others to distribute, remix, adapt, build upon this work non-commercially,and license their derivative works on different terms, provided the original work is
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management committee: ​dataadmin@​jages.​net. The data set has ethical or legal
restrictions because it includes human participants.