近藤 克則

Elder abuse is a serious public health concern that increases the risks of negative health outcomes globally. It is well known that abuse in older adults is associated with depression; however, longitudinal studies investigating the causal relationship between these events are scarce. Because the cause precedes the result over time, the temporal relationships between abuse and depression should be verified from each direction. This longitudinal study, therefore, investigated and clarified whether depression causes or results from elder abuse among older Japanese adults. Two longitudinal analyses were conducted using data derived from the Japan Gerontological Evaluation Study. The data were collected in 2010 and 2013 through a mail survey of 1,737 people (983 females, 754 males) across Japan. Of those who did not experience abuse in 2010, 38 (5.0%) males and 53 (5.4%) females newly experienced abuse in 2013. Among respondents who did not have depressive symptoms in 2010, 60 (8.0%) males and 61 (6.2%) females newly reported depressive symptoms in 2013. After adjusting for demographic factors in Analysis 1, people who experienced abuse were 2.28-fold (95% confidence interval [CI] = 1.68–3.09) more likely to have depressive symptoms three years later than those who were not abused. In Analysis 2, respondents who had mild or severe depression in 2010 were 2.23-fold (95% CI = 1.61–3.10) more likely to have experienced abuse after three years than those who did not have depression. After adjusting for several demographic factors, the results showed that abuse can lead to depression and that depression can be a cause of abuse. Therefore, preventing abuse should be considered from both directions.

The Great East Japan Earthquake created health hazards for many people. Using Panel Data gathered in Iwanuma city, Japan, at two points in time (in 2010 before the quake, and in 2013 after the quake), we found that the high degree of housing damage negatively affected victims’ self rated health (SRH) (direct effect), and decreased the levels of their social connections, which in turn also had a harmful effect on their SRH (indirect effect). We also found that although the direct impacts of earthquakes disappear relatively quickly, the harmful indirect effects associated with a decrease in social connections are slower to dissipate. We conducted a first-difference two-step GMM estimation to consider the possible problem of endogeneity. The results support the above conclusion, and show that in the short-term, the indirect impacts of the earthquake accounted for 55 % of all the impacts experienced.

Importance: Trust is a core component of social cohesion, facilitating cooperation and collective action in the face of adversity and enabling survivors to remain resilient. Residential stability is an important prerequisite of developing trusting relations among community members. However, little is known about whether the movement of internally displaced persons (IDPs) after a disaster might change community relations. Objective: We explored perceived changes in trust within 1 community directly impacted by the 2011 Great East Japan Earthquake and Tsunami. Design, Setting, and Participants: This prospective cohort study examined survey data from 3594 residents of Iwanuma City, Japan, aged 65 years or older. Data were obtained from the Iwanuma Study-part of the Japan Gerontological Evaluation Study, a nationwide cohort study established in 2010-approximately 7 months before the disaster. All Iwanuma City residents age 65 years or older (8576 residents) were eligible to participate in 2010. The response rate was 59.0% (5058 residents). A follow-up survey was conducted in 2013, approximately 2.5 years after the disaster. Of the 4380 remaining participants who answered the baseline survey, 3594 were recontacted (follow-up rate, 82.1%). Data analysis was performed from July 1, 2019, to January 9, 2020. Exposures: The number of temporarily relocated Iwanuma City survivors within 100 m and 250 m of a nonrelocated resident's home address. Main Outcomes and Measures: Perceived changes in particularized trust (ie, trusting people from the same community) and generalized trust (trusting people from other communities) measured on a 5-point Likert scale. Results: Among 3250 nonrelocated residents (1808 [55.6%] women; mean [SD] age, 76.5 [6.2] years) of Iwanuma City included in the analytic sample, multivariable-adjusted multinomial logistic regression analyses found that each standard deviation increase in the influx of internally displaced persons (1 SD = 11 IDPs) within 250 m of a resident's home address was associated with higher odds of a decrease in the resident's particularized and generalized trust (odds ratio, 1.17; 95% CI, 1.04-1.32). Conclusions and Relevance: The influx of IDPs in the host community appeared to be associated with an erosion of trust among locals. To avoid the erosion of social cohesion after a disaster, it may be crucial to provide opportunities for social interaction between old and new residents of communities.

目的 超高齢社会において、認知症予防は重要な課題である。先行研究では、趣味を有する高齢者は認知症リスクが低く園芸、観光、スポーツ系の趣味を行っている者では認知症リスクが低いと報告されている。しかし、趣味の種類の数が増えれば効果も上乗せされるのか、またたとえばスポーツ系の中でも種類によって認知症の発症リスクが異なるのかは明らかでない。本研究の目的は、趣味の種類および数と認知症発症との関連を、約6年間の大規模縦断データを用いて明らかにすることである。方法 日本老年学的評価研究(JAGES)が2010年に実施した要介護認定を受けていない高齢者を対象とした調査の回答者で、年齢と性に欠損がない56,624人を6年間追跡した。趣味の質問に有効回答が得られた者のうち、追跡期間が365日未満の者を除く49,705人を分析対象者とした。アウトカムの認知症発症は、365日以降の認知症を伴う要介護認定の発生と定義した。実践者割合が5%以上の趣味の種類(男性14種類、女性11種類)およびその数(0～5種類以上)を説明変数とし、基本属性、疾患、健康行動、社会的サポート、心理・認知機能、手段的日常生活動作能力の計22変数を調整したCox比例ハザードモデルを用いハザード比(HR)を算出した。結果 追跡期間中に4,758人(9.6%)に認知症を伴う要介護認定が発生した。男女いずれも、認知症リスク(HR)はグラウンド・ゴルフ(男:0.80、女:0.80)、旅行(男:0.80、女:0.76)を趣味としている者において、それらが趣味ではない者と比較して低かった。さらに男性ではゴルフ(0.61)、パソコン(0.65)、釣り(0.81)、写真撮影(0.83)、女性では手工芸(0.73)、園芸・庭いじり(0.85)を趣味とする者で低かった。男女ともに趣味の種類の数が多くなるほど認知症発症リスクが低くなる有意なトレンドが確認された(男:0.84、女:0.78)。結論 男女ともグラウンド・ゴルフ、旅行が趣味の者では認知症リスクが低く、また趣味の種類の数が増えるほどリスクは低下することが示唆された。本研究で有意な関連が見られた趣味の種類を中心に、高齢者が多様な趣味を実践できる環境づくりが、認知症予防を効果的に進めるうえで重要であることが示唆された。(著者抄録)

© International & American Associations for Dental Research 2020. Despite their prevalence and burdens, oral diseases are neglected in universal health coverage. In Japan, a 30% copayment (out of pocket) by the user and a 70% contribution by Japan’s universal health insurance (JUHI) are required for dental and medical services. From the age of 70 y, an additional 10% is offered by JUHI (copayment, 20%; JUHI, 80%). This study aimed to investigate the effect of cost on dental service use among older adults under the current JUHI system. A regression discontinuity quasi-experimental method was used to investigate the causal effect of the JUHI discount policy on dental visits based on cross-sectional data. Data were derived from the 2016 Japan Gerontological Evaluation Study. This analysis contained 7,161 participants who used JUHI, were aged 68 to 73 y, and responded to questions regarding past dental visits. Analyses were controlled for age, sex, number of teeth, and equalized household income. Mean ± SD age was 72.1 ± 0.79 y for the discount-eligible group and 68.9 ± 0.78 y for the noneligible group. During the past 12 mo, significantly more discount-eligible participants had visited dental services than noneligible participants (66.0% vs. 62.1% for treatment visits, 57.7% vs. 53.1% for checkups). After controlling for covariates, the effect of discount eligibility was significant on dental treatment visits (odds ratio [OR], 1.36; 95% CI, 1.32 to 1.40) and dental checkups (OR, 1.49; 95% CI, 1.44 to 1.54) in the regression discontinuity analysis. Similar findings were observed in triangular kernel-weighted models (OR, 1.38 [95% CI, 1.34 to 1.44]; OR, 1.52 [95% CI, 1.47 to 1.56], respectively). JUHI copayment discount policy increases oral health service utilization among older Japanese. The price elasticity for dental checkup visits appears to be higher than for dental treatment visits. Hence, reforming the universal health coverage system to improve the affordability of relatively inexpensive preventive care could increase dental service utilization in Japan.

© 2020 Elsevier Ltd The underlying mechanism for deterioration in cardiometabolic health after major natural disasters is unknown. We leveraged natural experiment data stemming from the 2011 Great East Japan Earthquake and Tsunami (n = 1165) to examine whether specific types of post-disaster accommodations explain the association between disaster-related property damage and objectively measured cardiometabolic profiles of older disaster survivors. Causal mediation analysis showed that relocation to trailer-style temporary shelters largely mediated the associations between home loss and unhealthy changes in anthropometric measures (72.6% of 0.65 kg/m2 for body mass index and 62.3% of 3.89 cm for waist circumference), but it did not mediate the associations with serum lipid measures. This study demonstrates that there are outcome-specific pathways linking disaster damage and health of survivors.

© 2020 The Authors Socioeconomic disadvantage is a risk factor for arthritis, but its causal relationship remains unclear. This study examined the causal relationship between socioeconomic circumstances and new-onset arthritis by taking advantage of the “natural experiment” that resulted from the Great East Japan Earthquake and Tsunami. The baseline survey was conducted in August 2010, 7 months before the disaster. Self-reported questionnaires were mailed to all eligible residents of Iwanuma City in Miyagi Prefecture. The earthquake and tsunami occurred on March 11, 2011. The follow-up survey was conducted in October 2013, as well as the gathering of information about disaster damage (housing damage and subjective deterioration of economic circumstances) and health-related information. We used a two-stage least squares instrumental variable model to analyze 2360 survivors who did not have arthrosis at baseline, of whom 95 (4.0%) developed arthritis over the 2.5-year follow-up period. We used the linear probability model for the estimations. Our results revealed that both the subjective deterioration of economic circumstances and housing damage were associated with the development of arthritis (95% confidence interval [CI], 0.08 [0.03–0.12] and 0.02 [0.01–0.04], respectively). In addition, we also found that the disruption of access to orthopedics was associated with the development of arthritis. Our findings added robust evidence of the causal relationship between worsening economic circumstances and the development of arthritis. Our study emphasized the importance of recovery as well as the establishment of the post-disaster orthopedic medical system in the aftermath of a disaster.

Background: The association between neighborhood environment and health may be biased due to confounding by residential self-selection. The displacement of disaster victims can act as a natural experiment that exposes residents to neighborhood environments they did not select, allowing for the study of neighborhood effects on health. Methods: We leveraged data from a cohort of older adults 65 years of age or older living in Iwanuma, Japan, located 80 km west of the 2011 Great East Japan Earthquake and Tsunami. Surveys were conducted 7 months before the disaster, as well as 2.5 and 5.5 years afterward, and linked with medical records. We classified each individual's type of exposure to neighborhood environment based on proximity to local food and recreation destinations and walkability. Results: Fixed-effect models indicated that change in the exposure type from low to high urban density was associated with increased body mass index (0.46 kg/m(2); 95% confidence interval [CI] = 0.20, 0.73), waist circumference (1.8 cm; 95% CI = 0.56, 3.0), low-density lipoprotein cholesterol (11 mg/dl; 95% CI = 5.0, 17), and decreased high-density lipoprotein cholesterol (-3.1 mg/dl; 95% CI = -5.0, -1.3). We observed similar trends when we analyzed only the individuals who experienced postdisaster relocation to temporary homes. Conclusions: Increased proximity to food outlets was simultaneously correlated with greater walkability and accessibility to recreational destinations; however, any protective association of physical activity-promoting built environment appeared to be offset by proximity to unhealthy food outlets, especially fast-food restaurants and bars.

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BACKGROUND: This study aimed to investigate whether care capacity for patients following stroke contributes to improved activities of daily living (ADL) at discharge from hospital based on the degree of stroke severity. DESIGN: Retrospective, observational, longitudinal study. SETTING: Acute phase hospitals. PARTICIPANTS: From 2005 to 2011, 5006 patients with stroke at acute phase hospitals were registered in a database. There were 2501 individuals from 11 hospitals who met the following four criteria: (1) a pre-stroke modified Rankin Scale (mRS) score of 0-3; (2) admission to hospital within 7 days of suffering a stroke; (3) ischemic or hemorrhagic stroke; and (4) staying in hospital for 8-60 days. MAIN OUTCOME MEASURES: The main outcome measure was the Functional Independence Measure (FIM, version 3.0) score at discharge. The FIM is an internationally used scale, which is used as an ADL outcome assessment scale for after rehabilitation. RESULTS: Among patients with stroke, those with care capacity had higher FIM scores at hospital discharge than did those without care capacity (unstandardized coefficient = 2.3, P = 0.015). Examination of this relationship by stroke severity showed that the FIM score at discharge was only significantly higher in patients who suffered from a moderate to severe stroke (unstandardized coefficient = 7.0, P = 0.040). No associations were observed in patients who suffered from minor, moderate, or severe stroke. CONCLUSIONS: These results suggest that care capacity facilitates total recovery of the FIM, especially among patients who suffer from a moderate to severe stroke.

Restrictions on going out, meeting other people, and participating in activities during the COVID-19 (coronavirus disease-2019) pandemic may have a prolonged effect on older people. This article discusses the importance of social relationships in the health of older people based on the results of the Japan Gerontological Evaluation Study (JAGES) that has conducted nationwide longitudinal studies. We selected cohort studies of JAGES, which investigated the relationships between social relationships and health, with more than 10 000 participants and published after 2010. The results showed that having contact with others, eating with others, and participating in social activities were negatively related to incident dementia, functional disability, depression, and premature death. A minimum of weekly contact with others, eating with others, and social participation by maintaining physical distancing are needed, even during the COVID-19 pandemic. For reducing the risks of transmission of coronavirus and its negative effects on health in the future, using the internet may be beneficial. The development of technological support networks for older people may be necessary.

AIM: Weight and height are usually self-reported in population-based epidemiological surveys. While the accuracy of self-reports has been extensively studied in younger populations, less is known in older populations. We investigated the accuracy of self-reported weight, height and body mass (BMI) in an older cohort in Japan, where overweight/obesity and underweight coexist. METHODS: We used data from older Japanese adults (≥65 years) participating in the Japan Gerontological Evaluation Study in 2016 to 2017 (7357 men and 9271 women). Self-report data were linked to objective data obtained from clinical examinations. RESULTS: The mean ± standard deviation (SD) age was 74.5 ± 5.8 years, mean ± SD weight, height and BMI were 55.7 ± 10.1 kg, 156.0 ± 8.9 cm and 22.8 ± 3.1, respectively. Results showed high intraclass correlation coefficients for self-reported and measured values (0.97 for weight; 0.96 for height). While weight/height were overestimated among men (weight by 0.096 kg; height by 0.27 cm) and women (weight by 0.18 kg; height by 0.27 cm), BMI tended to be slightly underestimated (-0.034 kg/m2 for men; -0.037 kg/m2 for women). However, the absolute differences between self-reported and measured values were not negligible; people had a higher risk for both under- and overestimation of their BMI category with increasing age. Lower education predicted BMI overestimation, whereas lower income predicted BMI underestimation. CONCLUSIONS: Overall accuracy of self-reported body habitus was higher in this cohort of older Japanese compared with previous reports. Nevertheless, misclassification of BMI due to the misreporting of their weight/height was more common among the oldest-old, as well as those with lower education and income. Geriatr Gerontol Int 2020; 20: 803-810.

Japan has the highest life expectancy in the world. However, this does not guarantee an improved quality of life. There is a gap between life expectancy and healthy life expectancy. This study aimed to reveal the features of healthy life expectancy across all secondary medical areas (n= 344) in Japan and examine the relationship among healthcare resources, life expectancy, and healthy life expectancy at birth. Data were collected from Japan's population registry and long-term insurance records. Differences in healthy life expectancy by gender were calculated using the Sullivan method. Maps of healthy life expectancy were drawn up. Descriptive statistics and correlation analysis were used for analysis. The findings revealed significant regional disparities. The number of doctors and therapists, support clinics for home healthcare facilities and home-visit treatments, and dentistry expenditure per capita were positively correlated with life expectancy and healthy life expectancy (correlation coefficients > 0.2). They also revealed gender differences. Despite controlling for population density, inequalities in healthy life expectancy were observed, highlighting the need to promote social policies to reduce regional disparities. Japanese policymakers should consider optimal levels of health resources to improve life expectancy and healthy life expectancy. The geographical distribution of healthcare resources should also be reconstituted.

OBJECTIVE: To compare the change in the prevalence of social isolation from 2010 to 2016 between older populations in Japan, the most aging and socially isolated country, and England, a country known for advanced social isolation measures. METHODS: Surveys from the Japan Gerontological Evaluation Study (JAGES) and the English Longitudinal Study of Aging (ELSA) included 70,751 and 4134 participants, respectively, aged 65 years or older in 2010 and 94,228 and 4295 participants in 2016. We assessed the social isolation of respondents on a scale from 0 to 5 points based on lack of social interactions with a spouse or partner, children, relatives, or friends and nonparticipation in any organization. RESULTS: Results of two-way analysis of variance confirmed significant interactions (nation × period) in men and women aged 65-74 years and women aged 75 years or older. In JAGES, all had higher scores in 2016 compared to 2010 (1.64-1.76, 1.28-1.36, and 1.55-1.60 points, respectively). Furthermore, the proportions of those with lack of interaction with relatives increased (52.7%-58.9%, 31.5%-41.1%, and 25.2%39.2%, respectively). In ELSA, women aged 75 years or older demonstrated a significantly lower mean score in 2016 than in 2010 (1.40 vs. 1.21). No significant changes were observed in other groups. CONCLUSION: Social isolation among older adults is more severe in Japan than in England. The difference has widened, especially for women and younger older adults. This is attributed to the weakening relationships with relatives in Japan.

BACKGROUND: Existing evidence suggest that those who are socially isolated are at risk for taking up or continuing smoking. This study investigated country-based differences in social isolation and smoking status. METHODS: We performed a repeated cross-sectional study using two waves of data from two ongoing aging studies: the English Longitudinal Study of Ageing and the Japan Gerontological Evaluation Study. Participants from both studies aged ≥65 years old were included. We applied a multilevel Poisson regression model to examine the association between social isolation and smoking status and adjusted for individual sociodemographic characteristics. We used the social isolation index which comprises the following domains: marital status; frequency of contact with friends, family, and children; and participation in social activities. Interaction terms between each country and social isolation were also entered into the mode. RESULTS: After exclusion of never smokers, we analyzed 75,905 participants (7,092 for ELSA and 68,813 for JAGES, respectively). Taking ex-smokers as the reference, social isolation was significantly associated with current smoking; the prevalence ratios (PRs; 95% credible intervals [CrIs]) were 1.06 (1.05-1.08) for men and 1.08 (1.04-1.11) for women. Taking Japan as a reference, the interaction term between country and social isolation was significant for both sexes, with increased PRs (95% CrIs) of 1.32 (1.14-1.50) for men and 1.30 (1.11-1.49) for women in England. CONCLUSIONS: Older people who were less socially isolated were more likely to quit smoking in England than in Japan, possibly explained by the strict tobacco control policies in England.

Widowhood and living alone are linked to increased risk of depression. We examined prospectively whether community-level social capital can mitigate the adverse impact of widowhood and living alone on depressive symptoms. We used data of the Japan Gerontological Evaluation Study of functionally independent adults aged 65 years or older. Three waves of surveys were collected in 2010, 2013 and 2016. We conducted gender-stratified multilevel linear regression to examine the moderating effects of community-level social capital on depressive symptoms (as assessed by the 15-point Geriatric Depression Scale) associated with widowhood and living alone. Widowhood in the past 12 months in combination with living alone was associated with a marked worsening in depressive symptoms among men (beta coefficient = 1.67; 95% confidence interval: 1.38, 1.95). Community-level civic participation, but not social cohesion or reciprocity, was associated with lower depressive symptoms in men and women. In addition, community-level civic participation moderated the association between depressive symptoms and recent widowhood/living alone among men (coefficient per 1 standard deviation = -0.30; 95% confidence interval: -0.59, -0.02). We found no significant effect modification of community-level social capital on depressive symptoms associated with widowhood and living alone among women. Communities with greater civic participation appear to mitigate the onset of depressive symptoms among recently widowed men living alone. Promotion of community activities might be an effective community-level intervention to promote mental health in this vulnerable group.

BACKGROUND: Although adverse childhood experiences (ACEs) have been linked to negative health behaviors in adulthood, few studies have investigated if the impact continues until late adulthood. We examined the association between ACEs and fruit and vegetable intake (FVI) among older adults in Japan. METHODS: Data came from the Japan Gerontological Evaluation Study (JAGES), 2013 in which 24,271 individuals aged ≥65 years participated. The number of ACEs was calculated (0, 1 and ≥2) while low FVI was defined as consuming fruit and vegetables less than once a day. A sex-stratified multilevel Poisson regression analysis was used to investigate the association between ACEs and low FVI. RESULTS: Among men, 35.4% reported at least one ACE while the corresponding figure for women was 30.6%. Compared to those without ACEs, the prevalence ratios for low FVI among those who reported ≥2 ACEs were 1.51 (95% confidence interval [CI] = 1.30-1.75) for women and 1.28 (95% CI = 1.14-1.44) for men after adjusting for age and childhood economic hardship. Although these associations were attenuated after adjusting for socio-demographic and health-related variables, the link between ACEs and low FVI remained statistically significant among women. Of the seven individual forms of ACE, psychological neglect was significantly associated with low FVI (PR = 1.16, 95% CI = 1.03-1.31) among women in the final model. CONCLUSIONS: ACEs are associated with low FVI among older Japanese adults. Our results suggest that the detrimental effect of ACEs on health behavior may stretch across the life course.

This cohort study examines the long-term trajectories of posttraumatic stress and depressive symptoms among older, community-living adults who were affected by the 2011 Great East Japan earthquake and tsunami.Question What is the persistence of mental illness symptoms among individuals affected by the 2011 Great East Japan earthquake and tsunami 5.5 years after the disaster? Findings In a cohort study of 2781 community-dwelling older adults, approximately half of the individuals who reported posttraumatic stress symptoms and depression after the disaster had recovered by 5.5 years. The overall prevalence of depression remained stable between predisaster and postdisaster data. Meaning In this study, although mental illness symptoms persisted for more than 5 years among half of disaster survivors, the community-wide prevalence of depression remained unchanged, suggesting that the community itself was resilient.Importance Posttraumatic stress symptoms (PTSS) and depressive symptoms are common among survivors of a major disaster, yet few longitudinal studies have documented their long-term persistence at the community level. Objective To examine the trajectories of PTSS and depressive symptoms for as long as 5.5 years after the 2011 Great East Japan earthquake and tsunami. Design, Setting, and Participants This cohort study used data from 2781 participants in 3 waves of the Iwanuma Study (2010, 2013, and 2016), a cohort of community-dwelling older adults (>= 65 years in August 2010) in Iwanuma, Japan, who were directly affected by the 2011 disaster. The baseline assessment of mental health predated the disaster by 7 months, and survivors were followed up for 5.5 years after the disaster. Data analysis was performed from October 2019 to February 2020. Exposures The March 11, 2011, Great East Japan earthquake and tsunami. Main Outcomes and Measures PTSS were measured by 9 questions on the Screening Questionnaire for Disaster Mental Health, while depressive symptoms were measured by 15 items on the Geriatric Depression Scale short form. Results The analytic samples for trajectories of PTSS and depressive symptoms included 2275 and 1735 respondents, respectively. In the study population at baseline, there were slightly more women (1262 of 2275 [55.5%] and 882 of 1735 [50.8%]), and most participants were aged 65 to 74 years (1533 [67.4%] and 1224 [70.5%]) and married (1664 [76.2%] and 1319 [77.7%]). Overall, there was a 13.6% (95% CI, 11.7%-15.6%) incidence of depression among individuals who did not have depression before the disaster, while a further 11.1% (95% CI, 9.8%-12.4%) reported PTSS after the disaster. By 5.5 years of follow-up, approximately half of the survivors with new depressive symptoms in 2013 (85 of 168 [50.6%]) and PTSS (147 of 253 [58.1%]) had recovered. The prevalence of depression in the community remained remarkably stable (between 504 participants [29.0%] and 506 participants [29.2%]) comparing predisaster and postdisaster data. Conclusions and Relevance In this study, mental illness symptoms persisted for more than 5 years among half of disaster survivors, but the community-wide prevalence of depression remained stable, suggesting that the community itself was resilient.

Countries with different oral health care systems may have different levels of oral health related inequalities. We compared the socioeconomic inequalities in oral health among older adults in Japan and England. We used the data for adults aged 65 years or over from Japan (N = 79,707) and England (N = 5115) and estimated absolute inequality (the Slope Index of Inequality, SII) and relative inequality (the Relative Index of Inequality, RII) for edentulism (the condition of having no natural teeth) by educational attainment and income. All analyses were adjusted for sex and age. Overall, 14% of the Japanese subjects and 21% of the English were edentulous. In both Japan and England, lower income and educational attainment were significantly associated with a higher risk of being edentulous. Education-based SII in Japan and England were 9.9% and 26.7%, respectively, and RII were 2.5 and 4.8, respectively. Income-based SII in Japan and England were 9.2% and 14.4%, respectively, and RII were 2.1 and 1.9, respectively. Social inequalities in edentulous individuals exist in both these high-income countries, but Japan, with wider coverage for dental care, had lower levels of inequality than England.

We examined prospectively whether community-level social capital can mitigate the adverse effects of natural disaster on cognitive decline in the aftermath of the 2011 Great East Japan Earthquake and Tsunami. The baseline for our natural experimental study was established seven months before the disaster in a survey of older community-dwelling adults who lived in Iwanuma City, Japan, located 80 km west of the epicenter. Two and a half years after the disaster, we conducted a follow-up survey of survivors to gather information about their personal experiences during the disaster (n = 3560; 82.1% follow-up rate). Our primary outcome was the level of cognitive disability (measured on an 8-level scale) assessed within people's homes. Factor analysis established two subscales of community social capital: a cognitive dimension (perceptions of community social cohesion) and a structural dimension (informal socializing and social participation). The prevalence of cognitive decline at follow-up (11.5%) was three times higher than at baseline (4.2%). Our multiple membership multilevel model indicated that pre-versus post-disaster increases in community-level informal socializing and social participation were associated with lower risk of cognitive decline (coefficient = -0.12, 95% confidence interval: -0.20 to -0.04). In addition, social capital mitigated the risk of cognitive decline due to housing damage (interaction effect coefficient = -0.07, 95% confidence interval: -0.14 to -0.01). Community-level informal socializing and social participation buffers the impact of housing damage on cognitive decline in the aftermath of natural disaster. Relocating residents together with other community members may help to preserve community social capital and improve the cognitive resilience of older survivors.

AIM: To examine whether patterns of social participation vary in their associations with functional disability. METHODS: Data from 44 978 participants (22 750 men and 22 228 women) who participated in the 2010 Japan Gerontological Evaluation Study were analyzed; a study of those aged ≥65 years from 23 municipalities in eight prefectures. Social participation information was obtained at baseline with an eight-item questionnaire. Incidence of functional disability from 2010 to 2013 was defined as a new certification of eligibility for municipal public long-term care insurance. Social participation patterns were analyzed using exploratory factor analysis and participants were classified into quartiles of factor scores of social participation patterns. A competing risk model was used to calculate the hazard ratios and 95% confidence intervals for the incidence of functional disability in 3 years of follow-up. RESULTS: Two social patterns were identified: sports groups/clubs and hobby groups, and political groups/organizations and industry/trade associations. For both patterns, compared with participants in the lowest quartile, participants in the highest quartile were more likely to be male, college educated, high-income and current drinkers. Both patterns were associated with reduced incidence of functional disability (adjusted hazard ratios for top quartile of sports and hobby pattern: 0.66, 95% confidence interval: 0.59, 0.74; for political and industry/trade pattern: 0.81, 95% confidence interval: 0.72, 0.90; P for trend <0.001 for both). CONCLUSIONS: Those whose social participation patterns were characterized by frequent participation in sports groups/clubs and hobby groups or political groups/organizations and industry/trade associations were less likely to develop a functional disability. Geriatr Gerontol Int 2020; ••: ••-••.