Physical Frailty and Risk of Needing Long-Term Care in Community-Dwelling Older Adults: a 6-Year Prospective Study in Japan

Abstract

Objective: To examine the association between physical frailty and risk of needing long-term care, and compare the predictive value and clinical usefulness of a simple frailty scale (FRAIL) with that of the original Cardiovascular Health Study (CHS) criteria.

Design and setting: A 6-year prospective cohort study of community-dwelling older adults in a west Japanese suburban town.

Participants: 1,554 older adults aged 65 years and over who were initially free of long-term care needs at baseline.

Measurements: Physical frailty was defined by the CHS criteria and the FRAIL scale. The onset of needing long-term care was ascertained using national records of certification of long-term care needs. Cox proportional hazard models were used to estimate the association between physical frailty and risk of needing long-term care. Decision curve analysis was performed to compare the clinical usefulness of the two physical frailty criteria.

Results: During a median follow-up of 5.8 years, 244 were ascertained as needing long-term care. Baseline physical frailty was significantly associated with elevated risk of needing long-term care, with a multivariable-adjusted hazard ratio (HR) of 2.00 (95% confidence interval [CI], 1.32-3.02) for being frail and 1.50 (95% CI, 1.10-2.03) for being pre-frail as defined by the CHS criteria, compared with being robust (p for trend = 0.001). Similar results were found for physical frailty defined by the FRAIL scale, with a multivariable-adjusted HR (95% CIs) of 2.11 (1.25-3.56) for being frail and 1.73 (1.28-2.35) for being pre-frail vs. being robust (p for trend < 0.001). The two physical frailty criteria had similar net benefits in identifying individuals at high risk for needing long-term care.

Conclusions: Physical frailty is significantly associated with an increased risk of needing long-term care in community-dwelling older adults in Japan. Compared with the original CHS criteria, the simple FRAIL scale has comparable predictive value and clinical usefulness for identifying individuals at risk for needing long-term care.

Keywords: Physical frailty; elderly; long-term care needs; prospective study.

Figure 1

Cumulative incidence for long-term care needs by physical frailty phenotype based on the CHS criteria and the FRAIL scale CHS, Cardiovascular Health Study

Figure 2

Decision curve analysis for 6-year risk of the onset of needing long-term care Gray thin line: assuming treatment of all subjects; horizontal line (on Y=0): assuming treatment of no subjects; black thick line: prediction based on CHS model; dotted line: prediction based on the FRAIL scale. Threshold probability refers to the cut-offs of predicted 6-year risk of needing long-term care for use in the decision to initiate intervention/treatment. CHS, Cardiovascular Health Study