Factors for the Change in Frailty Status During the COVID-19 Pandemic: A Prospective Cohort Study Over Six- and 12-Month Periods in Japan

Purpose: We aimed to verify the frailty status and the factors associated with the change in frailty status every six months during the COVID-19 pandemic.Methods: A prospective cohort study was conducted every six months. The survey forms were distributed to 1,953 community-dwelling older adults. The baseline was obtained from May to July 2020, November 2020 to January 2021, and again from May to July 2021. The frailty status was assessed using the frailty screening index. The Questionnaire for Medical Checkup of the Old-Old and the Questionnaire for Change for Life were used to assess health conditions and lifestyle. Multivariate generalized linear mixed-effects models were used to determine whether changes in frailty status were associated with health conditions and lifestyle.Results: The 404 survey forms were analyzed. Approximately 41.1% and 48.7% of the participants experienced worsened robustness after six and 12 months, respectively. Among the pre-frail participants at baseline, 18.5% and 15.4% experienced improvement, and 12.7% and 16.3% experienced worsening six and 12 months later, respectively. Among frail participants at baseline, 63.6% and 48.5% experienced improvement six and 12 months later, respectively. Decline in swallowing function (beta = 0.552) and leg muscle strength weakness (beta = 0.515) were significantly associated with the change in frailty status over six months, and leg muscle strength weakness (beta = 0.512) was significantly associated over 12 months.Conclusions: Risk factors associated with worsening health should be assessed for appropriate support. It is especially important to assess subjective leg muscle weakness in older adults.