近藤 克則

Background: The current study aimed to investigate the contextual effect of volunteer group participation on subsequent depressive symptoms in older people. Methods: We analyzed the longitudinal data of 37,552 people aged 65 years and older in 24 municipalities surveyed in the Japan Gerontological Evaluation Study. Volunteer group participation of older people was assessed in 2013 by one question and depressive symptoms were assessed by the Geriatric Depression Scale 15 in 2016. To investigate a contextual effect, we aggregated individual-level volunteer group participation by each residence area as a community-level independent variable. We conducted a two-level multilevel Poisson regression analysis using the Random Intercepts and Fixed Slopes Model. Results: The average proportion of community-level volunteer group participation was 10.6%. The results of the Poisson regression analysis showed that community-level volunteer group participation reduced the risk for the onset of depressive symptoms by 13% with a 10 percentage point increase in participation, after adjusting for sex, age, population density, total annual sunshine hours and annual rainfall (incident rate ratio, 0.87; 95% confidence interval, 0.78–0.98). Conclusions: Older people living in areas with higher volunteer group participation had a lower risk of developing depressive symptoms regardless of whether or not they participated in a volunteer group.

OBJECTIVE: Inequalities exist between the 23-valent pneumococcal polysaccharide vaccination (PPSV23) rate in each municipality among Japanese older adults. Exploring individual-level and community-level intervenable factors is necessary to improve the vaccination rates. We examined the associations between community-level and individual-level social capital and the PPSV23 vaccination among older Japanese adults using multilevel Poisson regression analyses. DESIGN: Cross-sectional study. SETTING: We used data from the Japan Gerontological Evaluation Study, conducted between 3 October 2016 and 10 January 2017 in 631 districts, 39 municipalities and 18 prefectures. PARTICIPANTS: The target population comprised persons aged 65 years or older who are physically and cognitively independent (that is, not certified as needing long-term care). Further, 180 021 older adults from 39 Japanese municipalities were enrolled. PRIMARY OUTCOME MEASURE: The primary outcome was the PPSV23 vaccination among the Japanese older adults aged 65 years or older who did not have physical or cognitive disabilities. RESULTS: After adjusting for municipality-, community-, individual-levels effects with multiple imputation, 137 075 individuals who participated in one/more of the civic participation (participation of social groups), social cohesion (social tie), or reciprocity (mutual exchange of social support) were significantly associated with more vaccinations than those without the three social capitals among the 137 075 older adults (13.0% (95% CI 11.0% to 14.9%), 5.0% (95% CI 2.4% to 7.6%) or 33.9% (95% CI23.6% to 44.2%) increase, respectively, p>0.001 for all). The rich (≥+1 SD) community-level civic participation was significantly associated with 3.4% increase [95% CI 0.02% to 6.78%, p<0.05] of the PPSV23 vaccination among the older adults compared to those with the poor or standard one. CONCLUSIONS: Older adults with one/more of the three social capitals at the both levels received more PPSV23 vaccinations than those without those social capitals. Therefore, fostering of those social capitals may improve the inequality of the PPSV23 vaccination rate among older adults in each municipality.

OBJECTIVE: Recently, there has been an increase in the number of people with dementia. However, no study has examined the association between community-level social support and the onset of incident dementia using multilevel survival analysis. DESIGN: A prospective cohort study. PARTICIPANTS AND SETTING: We analysed data pertaining to 15 313 (7381 men and 7932 women) community-dwelling adults aged 65 years or older who had not accessed long-term care insurance and were living in Aichi Prefecture (seven municipalities) in Japan. PRIMARY AND SECONDARY OUTCOME MEASURES: The association between community-level social support and onset of incident dementia was examined using the Japan Gerontological Evaluation Study, a prospective cohort study introduced in Japan in 2003. Incident dementia was assessed using Long-term Care Insurance records spanning 3436 days from the baseline survey. RESULTS: During the 10-year follow-up, the onset of incident dementia occurred in 1776 adults. Among older people, a 1% increase in community-level social support (in the form of receiving emotional support) was associated with an approximately 4% reduction in the risk of developing dementia, regardless of socio-demographic variables and health conditions (HR=0.96; 95% CI=0.94 to 0.99). CONCLUSIONS: Receiving community-level social support in the form of emotional support is associated with a lower risk of developing incident dementia.

We evaluated differences in the cumulative benefit costs of public long-term care (LTC) insurance services by employment status and frequency of community activities. A baseline survey was conducted on functionally independent older people from 12 municipalities as a nationwide survey from 2010 to 2011. Employment status was dichotomized, and community activity was assessed based on the frequency of participation in hobbies, sports clubs, or volunteering. We followed the respondents’ LTC service costs over a period of 6 years using public LTC claim records (n = 46,616). We adopted a classical linear regression analysis and an inverse probability weighting estimation with multiple imputation for missing values. Compared with non-participation in each community activity, the cumulative LTC costs among individuals who participated in hobbies or sports group activities at least twice a week were 1.23 (95% confidence interval: 0.73–1.72) to 1.18 (0.68–1.67) thousand USD lower per person over the 6-year period (28.7% to 30.1% lower, respectively). Similarly, the costs for employed persons were 0.55 (0.20–0.90) to 0.64 (0.29–0.99) thousand USD per person lower than among retirees (14.5% to 16.9% lower). Promoting employment opportunities and frequent participation in community activities among older adults may help reduce future LTC costs by around 20% as a result of extending healthy longevity.

This study aimed to determine the impact of physical activity on the cumulative cost of long-term care insurance (LTCI) services in a cohort of community-dwelling people (65 years and older) in Japan. Using cohort data from the Japan Gerontological Evaluation Study (JAGES) on those who were functionally independent as of 2010/11, we examined differences in the cumulative cost of LTCI services by physical activity. We followed 38,875 participants with LTCI service costs for 59 months. Physical activity was assessed by the frequency of going out and time spent walking. We adopted a generalized linear model with gamma distribution and log-link function, and a classical linear regression with multiple imputation. The cumulative LTCI costs significantly decreased with the frequency of going out and the time spent walking after adjustment for baseline covariates. LTCI’s cumulative cost for those who went out once a week or less was USD 600 higher than those who went out almost daily. Furthermore, costs for those who walked for less than 30 min were USD 900 higher than those who walked for more than 60 min. Physical activity among older individuals can reduce LTCI costs, which could provide a rationale for expenditure intervention programs that promote physical activity.

Background: Depression is a major health problem among older adults, for which previous studies have suggested tooth loss as a risk factor. This study examined the mediating effect of oral function and orofacial appearance in the relationship between tooth loss and depression. Methods: This three-year follow-up longitudinal study was based on a self-reported questionnaire targeting community-dwelling older adults aged ≥65 years. We used the incidence of depressive symptoms during follow-up as the outcome, the number of remaining teeth (≥20/≤19) as the exposure, and the deterioration of oral function and orofacial appearance (speaking, smiling, and eating) as mediators. We fitted the logistic regression model including confounders and calculated the natural indirect effect (NIE), natural direct effect, and the proportion mediated (PM) by the deterioration of oral functions by applying the causal mediation analysis framework. Results: The mean age of the 8,875 participants was 72.7 years (1SD=5.5) and 48.0% were male. Depressive symptoms developed during follow-up in 11.5% of the participants (n=1,024). The incidence for those with ≤19 and ≥20 remaining teeth was 13.1% and 9.2%, respectively. Total effect of fewer remaining teeth (≤19) on depressive symptoms was OR=1.30 (95%CI=1.12–1.51). Difficulty in speaking (NIE OR=1.03, 95%CI=1.00–1.06, PM=12.4%), problems in smiling (NIE OR=1.04, 95%CI=1.01–1.07, PM=16.9%), and difficulty in chewing (NIE OR=1.05, 95%CI=1.02–1.09, PM=21.9%) significantly mediated the relationship. Limitation: Selection bias due to dropout. Conclusion: Deterioration of oral function and orofacial appearance were mediating factors of the mechanism for the relationship between tooth loss and the incidence of depressive symptoms.

In Western countries, the most important part of the face in communication is the mouth, whereas it is the eyes in Asian countries; thus oral health could be more important in social interactions in Western countries. Our aim was to examine differences in the association between oral health status and social isolation among older people by comparing Japan and England. We used cross-sectional information obtained from adults aged 65+ in two ongoing prospective cohort studies: The Japan Gerontological Evaluation Study (JAGES, N = 120,195) and the English Longitudinal Study of Ageing (ELSA, N = 3,958). The dependent variable, social isolation score (SIS) was calculated from five factors (marital status, social support from children, social support from family, social support from friends, and social participation). The independent variables were self-reported number of remaining teeth (0, 1-9, 10-19, ≥20) and denture use (≥20 teeth, 10-19 teeth with denture, 10-19 teeth without denture, 0-9 teeth with denture, 0-9 teeth without denture), while the covariates in the model were: sex, age, educational attainment, self-rated health, number of comorbidities, household annual equivalized income, mental health status, daily living activities, and smoking status. We examined associations between oral health status and SIS by applying an ordered logit model by country. Compared to England, more Japanese participants were socially isolated (1.4% vs. 5.8%), but fewer were edentulous (13.1% vs. 7.7%). In both countries, poorer oral health further increased the odds of being socially isolated. Pooled analysis of the ordered logit model with an interaction term showed that the association of number of remaining teeth with SIS was stronger in edentulous participants and in England (odds ratio = 1.50, 95% Confidence interval:1.26-1.80). In both countries, oral health was associated with social isolation; this association could be stronger in England than in Japan.

Pneumonia is a leading cause of mortality among older adults worldwide. Recently, several studies reported that frailty was associated with mortality among older adults hospitalized due to respiratory infectious diseases, including pneumonia. However, it is unknown whether frailty is associated with susceptibility to and severity of pneumonia in functionally-independent community-dwelling older adults. In this study, we examined whether frailty increased the susceptibility to pneumonia and hospitalization in older adults. We used cross-sectional data from the Japan Gerontological Evaluation Study; the data was collected by using mail-based, self-reported questionnaires from 177,991 functionally-independent community-dwelling older adults aged ≥ 65 years. Our results showed that frailty was significantly associated with both occurrence of and hospitalization due to pneumonia after adjustments with covariates; (Preference ratio {PR} 1.92, 95% confidence interval {95% CI} [1.66-2.22] and PR 1.80, 95% CI [1.42-2.28], respectively, p < 0.001 for the both). Pre-frailty was associated only with the occurrence of pneumonia. Besides, the instrumental activity of daily living, physical strength, nutrition status, oral function, homeboundness, and depression status in frail older adults were associated with either or both occurrence of and hospitalization due to pneumonia. Our results suggest that frailty influenced the susceptibility to and severity of pneumonia in older adults.

AIM: There is a large discrepancy between people's preferred and actual place of death in Japan. To manage this discrepancy, this study aimed to identify the variability in preferred places of death and their associated factors among Japanese older people. METHODS: Cross-sectional survey data were collected in 2016 as part of the Japan Gerontological Evaluation Study, in which 20 204 participants were asked about their preferred place of death. Logistic regression analyses were conducted to examine the final determinants for home as the preferred place of death. RESULTS: Based on survey data, 35.8% of respondents preferred home as the place of death, 42.7% preferred some sort of facility and 21.5% were unsure. Those who preferred to be at home when receiving end-of-life care were more likely to be older in age, live with others, be employed, be homeowners, have lived in their current residence for a longer period, not be vaccinated for influenza in the past year, engage in physical work or intense sports, not have participated in end-of-life discussions regarding preferred place of death, have experienced relatives dying at home, practice norms of reciprocity, have a sense of attachment to their neighborhood, receive instrumental social support, interact with neighbors and live in a rural area. CONCLUSIONS: Factors related to community attachment were associated with choosing home as the preferred place of death. To fulfill the preferences of Japanese older people, a broad range of demographic, health, behavioral, social, cultural and environmental factors should be considered. Geriatr Gerontol Int 2021; 21: 345-352.

Two frequently encountered but underrecognized challenges for causal inference in studying the long-term health effects of disasters among survivors include: (a) time-varying effects of disasters on a time-to-event outcome and (b) selection bias due to selective attrition. We review approaches to overcome these challenges and show application of the approaches to a real-world longitudinal data of older adults who were directly impacted by the 2011 earthquake and tsunami (n=4,857). To illustrate the problem of time-varying effects of disasters, we examined the association between degree of damage due to the tsunami and all-cause mortality. We compared results from Cox regression assuming proportional hazards versus adjusted parametric survival curves allowing for time-varying hazard ratios. To illustrate the problem of selection bias, we examined the association between proximity to the coast (a proxy for housing damage from the tsunami) and depressive symptoms. We corrected for selection bias due to attrition in the two post-disaster follow-up surveys (conducted in 2013 and 2016) using multivariable adjustment, inverse probability censoring weighting, and survivor average causal effect estimation. Our results demonstrate that the analytic approaches ignoring time-varying effects on mortality and selection bias due to selective attrition may underestimate the long-term health effects of disasters.

BACKGROUND: Farmers may have an increased risk for poor mental health. In connection with this, factors specific to the neighborhood environment such as farm density and the type of agriculture, might be important for mental wellbeing. In this study we aimed to clarify the cross-level interaction on depressive symptoms between farm density at the neighborhood level by type of agriculture and the longest occupation of individuals (farmer or non-farmer). METHODS: Data came from the 2016 wave of the Japan Gerontological Evaluation Study (JAGES) that were linked to governmental agricultural data. Information was analyzed from 147,549 respondents aged 65 years or older, residing in 1024 neighborhoods in 39 municipalities. We calculated farm (crop or animal husbandry) density at the neighborhood level, dividing the number of agricultural management entities by the population. Three-level (individual, neighborhood, and municipality) Poisson regression analysis was used to calculate the prevalence rate ratios of depressive symptoms. RESULTS: The prevalence of depressive symptoms was higher among individuals whose longest occupation was farmer compared to non-farmer. The estimated probability of depressive symptoms by a cross-level interaction analysis showed that among farmers of both genders, those who were residing in neighborhoods where the farm density was low had a higher prevalence of depressive symptoms, regardless of the type of agriculture. The slope of the relationship between depressive symptoms and animal husbandry farm density varied by occupation, with a higher prevalence of depressive symptoms observed in male farmers compared to male non-farmers. CONCLUSIONS: The high prevalence of depressive symptoms among farmers in neighborhoods with a low farm density may reflect a scarcity of formal and informal social support in such communities. The health effects of the neighborhood environment on farmers, such as farm density, which may vary by the type of agriculture, should be further researched.

目的 積雪寒冷地域である北海道6町に在住する高齢者の近隣環境の認識と冬季における1日平均歩数の目標達成との関連を明らかにする。対象と方法 要介護認定を受けていない69〜78歳、569人を対象に、環境に関する自記式質問紙調査と、3軸加速度活動量計による活動量調査を行い、データの得られた457人を解析対象者とした。1日の平均歩数を厚生労働省の示す目標値によって、目標達成群(男性7,000歩以上、女性6,000歩以上)と目標未達成群に分類し分析を行った。結果 目標達成群には男性の13.1%、女性の17.2%が分類された。運動や散歩に適した公園や歩道があることはないことに比べ冬季の歩数の性別、年齢で調整した目標達成割合比は1.86(95% CI:0.92-3.74)、生鮮食料品が手に入る商店・施設・移動販売が身近にあることは、ないことに比べ0.90(95% CI:0.57-1.45)だった。考察 積雪寒冷地域であっても運動や散歩に適した公園や歩道があることで、冬季においても歩数を維持できる可能性が示唆された。(著者抄録)

目的 積雪寒冷地域である北海道6町に在住する高齢者の近隣環境の認識と冬季における1日平均歩数の目標達成との関連を明らかにする。対象と方法 要介護認定を受けていない69〜78歳、569人を対象に、環境に関する自記式質問紙調査と、3軸加速度活動量計による活動量調査を行い、データの得られた457人を解析対象者とした。1日の平均歩数を厚生労働省の示す目標値によって、目標達成群(男性7,000歩以上、女性6,000歩以上)と目標未達成群に分類し分析を行った。結果 目標達成群には男性の13.1%、女性の17.2%が分類された。運動や散歩に適した公園や歩道があることはないことに比べ冬季の歩数の性別、年齢で調整した目標達成割合比は1.86(95% CI:0.92-3.74)、生鮮食料品が手に入る商店・施設・移動販売が身近にあることは、ないことに比べ0.90(95% CI:0.57-1.45)だった。考察 積雪寒冷地域であっても運動や散歩に適した公園や歩道があることで、冬季においても歩数を維持できる可能性が示唆された。(著者抄録)

<sec><title>Objective</title>Social isolation is a risk factor for depression in older age. However, little is known regarding whether its impact varies depending on country-specific cultural contexts regarding social relationships. The present study examined the association of social isolation with depression onset among older adults in England, which has taken advanced measures against social isolation, and Japan, a super-aged society with a rapidly increasing number of socially isolated people. </sec><sec><title>Design</title>Prospective longitudinal study. </sec><sec><title>Setting</title>We used data from two ongoing studies: the English Longitudinal Study of Ageing (ELSA) and the Japan Gerontological Evaluation Study (JAGES). </sec><sec><title>Participants</title>Older adults aged ≥65 years without depression at baseline were followed up regarding depression onset for 2 years (2010/2011–2012/2013) for the ELSA and 2.5 years (2010/2011–2013) for the JAGES. </sec><sec><title>Primary outcome measure</title>Depression was assessed with eight items from the Centre for Epidemiologic Studies Depression Scale for the ELSA and Geriatric Depression Scale for the JAGES. Multivariable logistic regression analysis was performed to evaluate social isolation using multiple parameters (marital status; interaction with children, relatives and friends; and social participation). </sec><sec><title>Results</title>The data of 3331 respondents from the ELSA and 33 127 from the JAGES were analysed. Multivariable logistic regression analysis demonstrated that social isolation was significantly associated with depression onset in both countries. In the ELSA, poor interaction with children was marginally associated with depression onset, while in the JAGES, poor interaction with children and no social participation significantly affected depression onset. </sec><sec><title>Conclusions</title>Despite variations in cultural background, social isolation was associated with depression onset in both England and Japan. Addressing social isolation to safeguard older adults’ mental health must be globally prioritised. </sec>

Sidewalks are indispensable environmental resources for daily life in that they encourage physical activity. However, the percentage of sidewalks installation is low even in developed countries. We examined the association between neighborhood sidewalk environment and dementia in Japan. We conducted a 3-year follow-up (2010-2013) among participants in a Japan Gerontological Evaluation Study, a population-based cohort study of community-dwelling older adults. We ascertained the incidence of dementia for 76,053 participants from the public long-term care insurance system. We calculated sidewalk coverage (sidewalk area as a percentage of road area) within 436 residential neighborhood units using the geographic information system. Multilevel survival models were used to estimate hazard ratios (HR) for the incidence of dementia. During the follow-up, 5310 dementia cases were found. In urban areas, compared with the lowest quartile for sidewalk coverage, the HR was 0.42 (95% confidence interval (CI): 0.33-0.54) for the highest quartile, adjusting for individual covariates. After successive adjustments for other neighborhood factors (land slope, numbers of hospitals, grocery stores, parks, stations and bus stops, education level, and unemployment rate), the HR remained statistically significant (HR=0.75, 95% CI: 0.59-0.94). Living in neighborhoods with high sidewalks installation was associated with low dementia incidence in urban areas.

BACKGROUND: Increasing the coverage of vaccinations recommended by the World Health Organization in the older adult population is an urgent issue, especially in the context of avoiding co-epidemics during the current coronavirus disease 2019 crisis. The aim of this study was to examine factors associated with the quality of perceived patient-physician communication and whether this variable was associated with increased odds of vaccination. METHODS: We used cross-sectional data from the Japan Gerontological Evaluation Study conducted from October 2016 to January 2017. The participants were 22,253 physically and cognitively independent individuals aged 65 or older living in 39 municipalities in Japan. Multilevel logit models were used to estimate the odds of vaccination. RESULTS: Among the participants, 40.0% and 58.8% had received pneumococcal and influenza vaccinations as per the recommended schedule, respectively. People with low educational levels were more likely to have a family physician but rate their experience in asking questions lower than those with higher educational levels. Having a family physician and high rating for physicians' listening attitude were positively associated with increased odds of pneumococcal and influenza vaccinations. High rating for patients' questioning attitude and shared decision-making, compared to an ambiguous attitude toward medical decision-making, were positively associated with increased odds of pneumococcal vaccination. CONCLUSION: The results suggest that promotion of having a family physician, better patient-physician communication, and shared decision-making may encourage older adults to undergo recommended vaccinations.

BACKGROUND: Difficulties in communication due to vision, hearing and tooth loss have a serious impact on health. We compared the association between and attribution of each of these factors on social interaction. METHODS: This cross-sectional study examined data from the 2016 Japan Gerontological Evaluation Study (n=22 295) on community-dwelling people aged ≥65 years in Japan. The dependent variable was the frequency of meeting friends as a measure of social interaction, and less-than-monthly was defined as fewer social interactions. The independent variables were self-reported degrees of vision, hearing (5-point Likert scale) and tooth loss (five categories), with 'poor' or '0 teeth' defined as the worst category. Sex, age, educational attainment, comorbidity and residential area were used as covariates. Poisson regression analysis with multiple imputations was used to estimate the prevalence ratios (PRs) of fewer social interactions by each status. Subsequently, the population attributable fraction (PAF) was calculated to assess the public health impact. RESULTS: The number of participants with fewer social interactions was 5622 (26.9%). Proportions of fewer social interactions among those with the worst vision, hearing and number of teeth categories were 48.7%, 40.1% and 32.0%, respectively. Their corresponding PRs of fewer social interactions were 1.72 (95% CI 0.97 to 3.05), 1.35 (95% CI 0.99 to 1.85) and 1.23 (95% CI 1.10 to 1.37), respectively. The total PAF for vision, hearing and number of teeth was 8.3%, 5.0% and 6.4%, respectively. CONCLUSION: Self-reported vision, hearing and tooth loss were associated with fewer social interactions. The magnitude of these impairments was largest in vision, followed by tooth and hearing loss.

BackgroundAlthough the feasibility of randomized trials for investigating the long-term association between oral health and cognitive decline is low, deriving causal inferences from observational data is challenging. We aimed to investigate the association between poor oral status and subjective cognitive complaints (SCC) using fixed-effects model to eliminate the confounding effect of unobserved time-invariant factors.MethodsWe used data from Japan Gerontological Evaluation Study (JAGES) which was conducted in 2010, 2013, and 2016. β regression coefficients (95% confidence intervals) were calculated using fixed-effects models to determine the effect of deteriorating oral status on developing SCC. Onset of SCC was evaluated using the Kihon Checklist-Cognitive function score. Four oral status variables were used: awareness of swallowing difficulty, decline in masticatory function, dry mouth, and number of teeth.Results13,594 participants (55.8% women) without SCC at baseline were included. The mean age was 72.4 (SD = 5.1) for men and 72.4 (SD=4.9) for women. Within the 6-year follow-up, 26.6% of men and 24.9% of women developed SCC. The probability of developing SCC was significantly higher when participants acquired swallowing difficulty (β= 0.088; 0.065-0.111 for men, β= 0.077; 0.057-0.097 for women), decline in masticatory function (β=0.039; 0.021-0.057 for men, β= 0.030; 0.013-0.046 for women), dry mouth (β= 0.026; 0.005-0.048 for men, β= 0.064; 0.045-0.083 for women), and tooth loss (β= 0.043; 0.001-0.085 for men, β= 0.058; 0.015-0.102 for women).ConclusionsThe findings suggest that good oral health needs to be maintained to prevent the development of SCC, which increases the risk for future dementia.

Studies examining the long-term health consequences of residential displacement following large-scale disasters remain sparse. Following the 2011 Japan Earthquake and Tsunami, victims who lost their homes were resettled by two primary means: 1) group relocation to public housing or 2) individual relocation, in which victims moved into public housing by lottery or arranged for their own accommodation. Little is known about how the specific method of residential relocation affects survivors’ health. We examined the association between residential relocation and long-term changes in mental and physical well-being. Our baseline assessment predated the disaster by 7 mo. Two follow-up surveys were conducted ∼2.5 y and 5.5 y after the disaster to ascertain the long-term association between housing arrangement and health status. Group relocation was associated with increased body mass index and depressive symptoms at 2.5-y follow-up but was no longer significantly associated with these outcomes at 5.5-y follow-up. Individual relocation at each follow-up survey was associated with lower instrumental activities of daily living as well as higher risk of cognitive impairment. Our findings underscore the potential complexity of long-term outcomes associated with residential displacement, indicating both positive and negative impacts on mental versus physical dimensions of health.

PURPOSE: Oral health has been reported to have an impact on the activities of daily life such as chewing, eating, and laughing, while psychological factors such as depression and loneliness have been reported to affect oral health. Little is known, however, about the association between laughter and oral health in older adults. This study examined the bidirectional association between the frequency of daily laughter and oral health in community-dwelling older Japanese adults. METHODS: Our cross-sectional study employed data from the 2013 Japan Gerontological Evaluation Study's self-reported survey, which included 11,239 male and 12,799 female community-dwelling independent individuals aged 65 years or older. We defined the oral health status by the number of remaining teeth. The association between the self-reported frequency of laughter (almost every day, 1-5 days per week, 1-3 days per month, or almost never) and oral health was examined using logistic regression analysis. RESULTS: The participants with 10 or more teeth were significantly more likely to laugh compared with the edentulous participants, after adjusting for all covariates. Compared with those who almost never laughed, those who laughed 1-5 days per week were significantly less likely to be edentulous. After stratifying by sex, similar results were found only in the men for both analyses. CONCLUSION: There was a significant bidirectional association between frequency of laughter and oral health that was independent of socioeconomic and lifestyle factors among older adults.

This study validates the relationship between community-level sports group participation and the frequency of leaving the house and transtheoretical model stages of behavior change for exercise among older individuals who did not participate in a sports group. We used cross-sectional data from the 2016 Japan Gerontological Evaluation Study. The proportion of sports group participants at the community level was calculated using the data from 157,233 older individuals living in 1000 communities. We conducted a multilevel regression analysis to examine the relationship between the proportion of sports group participants and the frequency of leaving the house (1 day/week or less) and the transtheoretical model stages of behavior change for exercise. A statistically significant relationship was observed between a high prevalence of sports group participation and lower risk of homeboundness (odds ratio: 0.94) and high transtheoretical model stages (partial regression coefficient: 0.06) as estimated by 10 percentage points of participation proportion. Older individuals, even those not participating in a sports group, living in a community with a high prevalence of sports group participation are less likely to be homebound; they are highly interested and have numerous opportunities to engage in exercise.

Depression among older adults is one of the most critical public health issues. The proximity of elementary schools has been positively associated with neighborhood social cohesion and quality of life. However, no studies have identified an association between the proximity of elementary school and older adults' mental health. Therefore, this study aimed to examine the association between the proximity of elementary schools, one of the core facilities of neighborhood communities in Japan, and depression in older adults. A total of 131,871 participants (63,430 men 73.7 ± 6.1 years, 68,441 women 73.8 ± 6.2 years) were analyzed from the Japan Gerontological Evaluation Study (JAGES) 2016 survey. Logistic regression analysis showed that there was no association between distance to elementary school and depression among males. However, among females, compared with the participants living within 400 m from the nearest elementary school, the odds ratio of depression for those living between 400 and 799 m and more than 800 m away were 1.06 (95% confidence interval (CI) 1.00-1.12) and 1.07 (95% CI 1.00-1.15), respectively. The findings may be useful when considering the design of communities around elementary schools and the planning of facilities as a population-based approach to promote mental health of older women.

OBJECTIVE: Several studies have reported that laughter is associated with health benefits. In addition, social interactions, such as social relationships, social participation and so forth, have shown the association with not only health but also individual emotion. In this study, we conducted a cross-sectional study to examine the association between variety of social interactions and the frequency of laughter. DESIGN: Cross-sectional study. SETTING: Sampled from 30 municipalities in Japan. PARTICIPANTS: Non-disabled Japanese men (n=11 439) and women (n=13 159) aged ≥65 years using data from the Japan Gerontological Evaluation Study, which was conducted during October to December in 2013. PRIMARY OUTCOME MEASURES: Laughing almost every day by self-reported questionnaire. RESULTS: Poisson regression analysis with robust error variance was used to calculate prevalence ratios (PRs) for laughing almost every day according to each social relationship and its potential community-level environmental determinants. The prevalence of laughing almost every day tended to increase with increased variety in each social interaction after adjusting, instrumental activities of daily living, number of living together, working status, depression, self-reported economic status and residence year. Among men and women, multivariate-adjusted PRs (95% CIs) by comparing participants with the highest and lowest categories were 1.18 (1.04 to 1.35) and 1.16 (1.04 to 1.29) in positive life events; 1.26 (1.10 to 1.45) and 1.09 (0.96 to 1.24) in perceived positive changes in the area; 1.15 (1.04 to 1.28) and 1.17 (1.07 to 1.28) in social participations; 2.23 (1.57 to 3.16) and 1.47 (1.02 to 2.12) in social relationships and 1.25 (1.08 to 1.45) and 1.29 (1.15 to 1.45) in positive built environments. These associations were also preserved after the restriction of participants who were not in depression. CONCLUSIONS: This study shows that a greater variety of each social relationships and the potential community-level environmental determinants are associated with higher frequencies of laughter in Japan.

Some modifiable risk factors for dementia are closely related to oral health. Although eating and speaking abilities are fundamental oral functions, limited studies have focused on the effect of malnutrition and lack of social interaction between oral health and dementia. We investigated the mediating effects of nutritional and social factors on the association between the number of teeth and the incidence of dementia. This 6-y cohort study used data from the Japan Gerontological Evaluation Study targeting older adults aged 65 y and above. The number of teeth (exposure) and covariates in 2010 (baseline survey), mediators (weight loss, vegetable and fruit intake, homeboundness, social network) in 2013, and the onset of dementia (outcome) between 2013 and 2016 were obtained. The Karlson–Holm–Breen mediation method was applied. A total of 35,744 participants were included (54.0% women). The mean age at baseline was 73.1 ± 5.5 y for men and 73.2 ± 5.5 y for women. A total of 1,776 participants (5.0%) had dementia during the follow-up period. There was a significant total effect of the number of teeth on the onset of dementia (hazard ratio, 1.14; 95% CI, 1.01–1.28). Controlling for nutritional and social mediators, the effect of the number of teeth was reduced to 1.10 (95% CI, 0.98–1.25), leaving an indirect effect of 1.03 (95% CI, 1.02–1.04). In the sex-stratified analysis, the proportion mediated by weight loss was 6.35% for men and 4.07% for women. The proportions mediated by vegetable and fruit intake and homeboundness were 4.44% and 4.83% for men and 8.45% and 0.93% for women, respectively. Furthermore, the proportion mediated by social networks was 13.79% for men and 4.00% for women. Tooth loss was associated with the onset of dementia. Nutritional and social factors partially mediated this association.

OBJECTIVES: The purpose of this study was to examine the relationship between social participation (type/pattern) and mortality according to company size of the longest-held job among older men in Japan who have worked in the company. METHODS: Longitudinal data from the Japan Gerontological Evaluation Study were used in this study. Functionally independent individuals aged 65 years and older in Japan were surveyed. Work and community organizations (local community, hobbies, and sports) were used as social participation. A Cox proportional hazards model was used to calculate mortality hazard ratios. RESULTS: Analysis was carried out on 19 260 participants. A total of 2870 deaths occurred during the 6-year follow-up period. Those in companies with 49 or fewer employees had the highest prevalence of work participation and the lowest participation in any community organization. Regardless of company size, the mortality risk was significantly lower for participants in any social participation (eg, the hazard ratio for participation in a hobby organization among those with a company size of 49 employees or fewer was 0.74, 95% CI: 0.65-0.85) compared to nonparticipants whose company size was 49 or fewer employees. CONCLUSIONS: In Japan, although older men who have worked for small companies may have fewer benefits, their social participation may reduce their mortality risks. To avoid increasing health inequalities, it is necessary to create an environment in which they are more likely to participate in social activities.

In Japan, many adults prefer to die at home; however, few have their preferences actually come true. While discussions regarding place of death preferences (DPDPs) are important for older adults, they are poorly documented. Therefore, we investigated the factors associated with older Japanese men and women having DPDPs. We used cross-sectional survey data collected for the Japan Gerontological Evaluation Study (JAGES). We applied multivariable logistic regression analysis to calculate the odds ratio (ORs) of having DPDPs separately between men (n = 2,770) and women (n = 3,038) aged ≥ 75 years. We considered 17 potential factors associated with having DPDPs, which were classified as either demographic, healthcare, family, or community factors. Among participants, 50.1% had DPDPs: 1,288 men (44.3%) and 1,619 women (55.7%). Older adults, DPDPs were associated with 5 additional factors; e.g. having a primary care physician (ORs = 1.47 [men] and 1.45 [women]), as were those who gave family and friends advice (ORs = 1.26 [men] and 1.62 [women]), and having people who listened to their concerns (ORs = 1.70 [men] and 1.81 [women]). Among men, DPDPs were associated with 3 additional factors; e.g. humorous conversations with their spouse (OR = 1.60). Among women, only one factor-reading newspapers (OR = 1.43) was associated with having DPDPs. Social networks with primary care physicians, family members, and friends may be important factors in promoting DPDPs. These gender-based differences in older adults relating to DPDPs should be considered when developing interventions to promote advance care planning that includes DPDPs.

Depression in older adults is a public health challenge. We aimed to clarify the relationship between depression in older adults and three types of neighborhood greenspaces: trees, grasslands, and fields. We utilized data from the Japan Gerontological Evaluation Study (JAGES) performed in 2016. Multilevel logistic regression analysis was used for non-stratified and stratified analyses for the urban-rural regions. The target population comprised 126,878 older adults (age ≥ 65 years) who responded to the depression questions and were living in 881 neighborhoods in Japan. Depression was diagnosed based on a Geriatric Depression Scale score ≥5, and 20.4% of the study population had depression. In the pre-stratification analysis, areas with more greenspaces revealed lower odds of depression (odds ratio (OR) 0.95, 95% confidence interval (CI) 0.85-0.95). In urban areas, more trees correlated with lower odds of depression (OR 0.94, 95% CI 0.89-1.00). In rural areas, moderate amounts of grassland were associated with lower odds of depression compared to areas with fewer grasslands (OR 0.91, 95% CI 0.83-1.00). We found that urban areas with higher tree density and rural areas with moderate amounts of grassland were associated with lower odds of depression.