Intrinsic capacity and recent falls in adults 80 years and older living in the community: results from the ilSIRENTE Study

Abstract

Background Falls in older adults significantly impact overall health and healthcare costs. Intrinsic capacity (IC) reflects functional reserve and is an indicator of healthy aging. Aims To explore the association between IC and recent falls (≤ 90 days) in community-dwelling octogenarians from the Aging and Longevity in the Sirente geographic area (IlSIRENTE) study. Methods The Minimum Data Set for Home Care (MDS−HC) and supplementary questionnaires and tests were used to assess the five IC domains: locomotion, cognition, vitality, psychology, and sensory. Scores in each domain were rescaled using the percent of maximum possible score method and averaged to obtain an overall IC score (range 0−100). Results The study included 319 participants (mean age 85.5 ± 4.8 years, 67.1% women). Mean IC score was 80.5 ± 14.2. The optimal IC score cut-off for predicting the two-year risk of incident loss of at least one activity of daily living (ADL) was determined and validated in a subset of 240 individuals without ADL disability at baseline (mean age 84.7 ± 4.4 years, 67.1% women). Participants were then stratified into low (< 77.6) and high (≥ 77.6) IC categories. Those with high IC (63.9%) were younger, more often males, and had lower prevalence of recent falls, disability, multimorbidity, and polypharmacy. Logistic regression models including IC as a continuous variable revealed a significant association between higher IC and lower odds of falls. This association was significant in the unadjusted (odds ratio [OR] 0.96, 95% confidence interval [CI] 0.94–0.98, p < 0.001), age- and sex-adjusted (OR 0.96, 95% CI 0.94–0.98, p < 0.001), and fully adjusted models (OR 0.96, 95% CI 0.93–0.99, p = 0.003). When considering IC as a categorical variable, unadjusted logistic regression showed a strong association between high IC and lower odds of falls (OR 0.31, 95% CI 0.16–0.60, p < 0.001). This association remained significant in both the age- and sex-adjusted (OR 0.30, 95% CI 0.15–0.59, p < 0.001) and fully adjusted models (OR 0.33, 95% CI 0.16–0.82, p = 0.007). The locomotion domain was independently associated with falls in the unadjusted (OR 0.98, 95% CI 0.97–0.99, p < 0.001), age- and sex-adjusted (OR 0.97, 95% CI 0.96–0.99, p < 0.001), and fully adjusted model (OR 0.98, 95% CI 0.96–0.99, p < 0.001). Discussion This is the first study using an MDS−HC-derived instrument to assess IC. Individuals with higher IC were less likely to report recent falls, with locomotion being an independently associated domain. Conclusions Lower IC is linked to increased odds of falls. Interventions to maintain and improve IC, especially the locomotion domain, may reduce fall risk in community-dwelling octogenarians.