Supplementary Material for: Engagement in the community-based going-out programs and the association with physical frailty assessed by the Kihon Checklist: A cohort study

Introduction: In efforts to address the public health concern of physical frailty prevention, community-based programs without supervision are anticipated, yet efficacy has not been shown. We aimed to investigate the association of engaging in an unsupervised, community-based going-out program on the incidence of physical frailty among older adults.
Methods: A cohort observational study was employed. Following a baseline assessment during 2015 and 2017 in Japan, we observed 1,350 older adults engage in a community-based going-out program for 12 months. Participants were categorized into either a non-engaged or engaged group via propensity score matching. A follow-up survey (mean period = 920 ± 76 days) was conducted to investigate the occurrence of physical frailty using the Kihon Checklist. The incidence of frailty, absolute risk reduction, and number needed to treat for program engagement were calculated. The odds ratio (OR) in engaged group compared with the non-engaged group was determined in a logistic regression model.
Results: Incidence of frailty was 15.1% in non-engaged group (n = 107 out of 628) and 8.3% in the engaged group (n = 53 out of 628). The number needed to treat and its 95% confidence interval were 21 (12–63) after matching. Compared with matched non-engaged group (OR 1.0), the OR and 95% confidence interval of matched engaged group for occurrence of physical frailty were 0.61 (0.42–0.87).
Conclusions: Engaging in the unsupervised community-based going-out program could prevent one incidence of physical frailty in every 21 participants and may thus contribute to preventing physical frailty at the population level.