Factors for the change in frailty status during the COVID-19 pandemic: A prospective cohort study over six- and 12-month periods in Japan

We aimed to verify the frailty status and the factors associated with the change in frailty status during the COVID-19 pandemic. A three-wave cohort study was conducted every six months, 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. Multivariate generalized linear mixed-effects models were used to determine whether changes in frailty status were associated with health conditions and lifestyle. The 404 survey forms were analyzed. Decline in chewing 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. 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.