Association of community-level social capital with dementia: A multilevel nine-year longitudinal study using data from the Japan Gerontological Evaluation Study

Satoko Fujihara; Taishi Tsuji; Atsushi Nakagomi; Yasuhiro Miyaguni; Masamichi Hanazato; Go Muto; Katsunori Kondo

doi:10.1016/j.socscimed.2023.116316

Association of community-level social capital with dementia: A multilevel nine-year longitudinal study using data from the Japan Gerontological Evaluation Study

Soc Sci Med. 2023 Dec:338:116316. doi: 10.1016/j.socscimed.2023.116316. Epub 2023 Oct 14.

Authors

Satoko Fujihara¹, Taishi Tsuji², Atsushi Nakagomi³, Yasuhiro Miyaguni⁴, Masamichi Hanazato³, Go Muto⁵, Katsunori Kondo⁶

Affiliations

¹ Tokyo Metropolitan Institute for Geriatrics and Gerontology, Itabashi City, Tokyo, Japan; Center for Preventive Medical Sciences, Chiba University, Chiba City, Chiba, Japan. Electronic address: fujihara.s0821@gmail.com.
² Center for Preventive Medical Sciences, Chiba University, Chiba City, Chiba, Japan; Faculty of Health and Sport Sciences, University of Tsukuba, Bunkyo City, Tokyo, Japan.
³ Center for Preventive Medical Sciences, Chiba University, Chiba City, Chiba, Japan.
⁴ Department of Social Welfare, Nihon Fukushi University, Chita-gun, Aichi, Japan; Department of Gerontological Evaluation, Center for Gerontology and Social Science, Research Institute, National Center for Geriatrics and Gerontology, Obu City, Aichi, Japan.
⁵ Center for Preventive Medical Sciences, Chiba University, Chiba City, Chiba, Japan; Department of Hygiene, Kitasato University School of Medicine, Sagamihara City, Kanagawa, Japan.
⁶ Center for Preventive Medical Sciences, Chiba University, Chiba City, Chiba, Japan; Department of Gerontological Evaluation, Center for Gerontology and Social Science, Research Institute, National Center for Geriatrics and Gerontology, Obu City, Aichi, Japan.

PMID: 37875055
DOI: 10.1016/j.socscimed.2023.116316

Abstract

Background: Individual-level social capital prevents cognitive decline. However, a few studies have focused on the effects of community-level social capital on dementia. Therefore, we investigated the association between community-level social capital and dementia onset based on longitudinal study data on older adults in Japan.

Methods: We used longitudinal data from the Japan Gerontological Evaluation Study, obtained over nine years (2010-2019). In total, 35,921 physically and cognitively independent individuals (16,848 males and 19,073 females) aged ≥65 years and nested within 308 communities in seven municipalities participated in the study. Dementia onset was assessed using the public long-term care insurance registration. Social capital was assessed using three dimensions: civic participation, social cohesion, and reciprocity. We performed a two-level multilevel survival analysis stratified by sex, calculated hazard ratios (HRs), and 95% confidence intervals (CIs).

Results: During the follow-up, 6245 (17.4%) dementia onset cases were identified. The cumulative incidence of dementia was 16.2% in males and 18.4% in females. After adjusting for covariates, individual-level civic participation was associated with a lower incidence of dementia in both males and females (HR, 0.84; 95% CI, 0.77-0.92; HR, 0.78; 95% CI, 0.73-0.84). Community-level civic participation and social cohesion were associated with a lower incidence of dementia among females (HR, 0.96; 95% CI, 0.93-0.99; HR, 0.93; 95% CI, 0.88-0.98) and cross-level interaction on social cohesion among females (HR, 0.95; 95% CI, 0.90-0.99).

Conclusions: Living in a community with high civic participation and social cohesion is associated with a lower incidence of dementia among older females. Therefore, promoting civic participation and social cohesion in the community may be a useful population-based strategy to delay or prevent the onset of dementia.

Keywords: Dementia; Multilevel survival models; Older adults; Social capital.

MeSH terms

Aged
Dementia* / epidemiology
Female
Humans
Interpersonal Relations
Japan / epidemiology
Longitudinal Studies
Male
Social Capital*
Social Participation / psychology