Relationship between self-rated health, physical frailty, and incidence of disability among Japanese community-dwelling older adults: A longitudinal prospective cohort study

Abstract

Objective: Poor self-rated health (SRH) and physical frailty are both significant predictors of disability in older adults, but their joint association on health outcomes remain unclear. This study aimed to examine the relationship between SRH, physical frailty, and incidence of disability among community-dwelling older adults.

Methods: This longitudinal cohort study included 2838 older adults aged 65 years or older (mean age, 73.1 ± 5.9 years) living in Takahama, Japan, who participated in the baseline assessment from September 2015 to February 2017. Participants were followed prospectively until June 2021. SRH was assessed on a four-point scale, and frailty was evaluated using the Japanese version of the Cardiovascular Health Study criteria. Participants were categorized into four groups based on SRH (Good or Poor) and frailty status (Robust or Frail). Cox proportional hazard models were used to assess the association between these categories and the incidence of disability over a 5-year follow-up.

Results: During the median follow-up of 60 months, 349 of the 2838 participants developed a disability. The risk of disability was significantly higher in the Poor/Robust (HR 1.64, 95 % CI 1.20-2.25), Good/Frail (HR 2.58, 95 % CI 1.91-3.49), and Poor/Frail (HR 2.03, 95 % CI 1.37-3.01) groups than in the Good/Robust reference group.

Conclusions: Frail older adults who report good health were associated with the risk of disability, suggesting that discrepancies between subjective and objective health assessments may lead to adverse outcomes. Recognizing and addressing these discrepancies is crucial to promote successful aging.

Keywords: Discrepancy; Frailty; Functional disability; Long-term care insurance; Self-rated health.