Combinations of intrinsic capacity and frailty and their associations with self-rated health in community-dwelling older adults

Abstract

Background: Intrinsic capacity (IC) and frailty are distinct but complementary frameworks for understanding the heterogeneity of aging. Although both have been linked to self-rated health, little is known about how their combined status relates to older adults’ health perceptions. This cross-sectional study investigated how combinations of IC and frailty status were associated with self-rated health among community-dwelling older adults. Method: Data from 593 participants (mean age: 73.9 years, female: 62.2%) in the 2019 Tarumizu Study were analyzed. IC was evaluated across five key screening domains (cognition, vitality, sensory, locomotion, and psychological) using a 10-point scale, with scores ≥ 9 classified as high IC. Frailty was assessed using the Japanese version of the Cardiovascular Health Study criteria and dichotomized into robustness and frailty (pre-frailty or frailty). Self-rated health was assessed with a four-point item and dichotomized into good or poor. Participants were classified into four groups: robust with high IC, frailty with high IC, robust with low IC, and frailty with low-IC. Results: Group proportions were: 30.0% (robust with high IC), 23.1% (frailty with high IC), 15.9% (robust with low IC), and 31.0% (frailty with low IC). Multivariable logistic regression showed that only the frailty with low-IC group had significantly greater odds of poor self-rated health compared to the robust with high-IC group (OR = 3.55, 95% CI: 1.34–9.36). Conclusions: Co-occurrence of low IC and frailty was significantly associated with poor self-rated health. These findings suggest that considering IC and frailty may enhance understanding of self-rated health in later life.