Community social support and onset of dementia in older Japanese individuals: a multilevel analysis using the JAGES cohort data

• Main Authors: Jun Aida, Taishi Tsuji, Yuri Sasaki, Yasuhiro Miyaguni
• Format: Article
• Language: English
• Published: BMJ Publishing Group 2021-06-01
• Series: BMJ Open
• Online Access: https://bmjopen.bmj.com/content/11/6/e044631.full

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.