Abstract
OBJECTIVES: To examine whether physical frailty onset before, after, or in concert with cognitive impairment is differentially associated with fall incidence in community-dwelling older adults. DESIGN: A longitudinal observational study. SETTING AND PARTICIPANTS: Data from 1337 older adults age ≥65 years and free of physical frailty or cognitive impairment at baseline were obtained from the National Health Aging Trends Study (2011‒2017), a nationally representative cohort study of US older adult Medicare beneficiaries. METHODS: Participants were assessed annually for frailty (physical frailty phenotype) and cognitive impairment (bottom quintile of clock drawing test or immediate and delayed recall; or proxy-report of diagnosis of dementia or AD8 score of ≥2). Incident falls were ascertained annually via self-report. Multinomial logistic regression was performed to estimate the association between order of first onset of cognitive impairment and/or frailty and incident single or repeated falls in the 1-year interval following their first onset. RESULTS: Of the 1,337, 832 developed cognitive impairment first (termed "CI first"), 286 developed frailty first (termed "frailty first") and 219 had co-occurrence of cognitive impairment and frailty within one year (termed "CI-frailty co-occurrence") over 5 years. Overall, 491 (34.5%) had at least 1 fall during the 1-year interval following the onset of physical frailty and/or cognitive impairment. After adjustment, "CI-frailty co-occurrence" was associated with a more than 2-fold increased risk of repeated falls than "CI first" (odds ratio 2.35, 95% confidence interval 1.51‒3.67; P < .001). No significant difference was found between participants with "frailty first" and "CI first" (P = .07). In addition, the order of onset was not associated with risk of a single fall. CONCLUSIONS AND IMPLICATIONS: Older adults experiencing "CI-frailty co-occurrence" had the greatest risk of repeated falls compared with those with "CI first" and "frailty first". Fall risk screening should consider the order and timing of onset of physical frailty and cognitive impairment.