Long-Term Health and Cost Outcomes of a 24-Week Multicomponent Frailty Intervention in Older Adults.

Importance: While multicomponent frailty interventions have demonstrated short-term effectiveness, evidence on long-term health and cost outcomes is limited. Objective: To evaluate the 66-month health and cost outcomes of a multicomponent frailty intervention for older adults in rural Korea. Design, Setting, and Participants: This economic evaluation used data from the Aging Study of Pyeongchang Rural Area-Intervention Study, a nonrandomized clinical trial conducted from August 2015 to January 2017. Individual-level data were linked to National Health Insurance Service claims data through December 2021, and analyses were performed from June 2024 to August 2025. Participants were socioeconomically vulnerable adults aged 65 years and older living alone or receiving medical aid in a rural Korean community. Volunteers were enrolled in the intervention, while those who declined enrollment served as controls. Propensity score matching was performed using frailty, functional status, demographics, comorbidities, depression, and prior health service use. Intervention: A 24-week multicomponent program including structured exercise and nutrition, with depression management, deprescribing, and home hazard reduction provided by risk profile. Main Outcomes and Measures: Survival analyses assessed a composite of all-cause mortality or long-term care insurance eligibility over 66 months. Cost outcomes included cumulative health service-use costs and cost:benefit ratios, calculated as incremental costs relative to intervention costs. Results: Among 383 eligible adults, 187 volunteered to participate and 196 individuals served as controls; NHIS linkage was successful for 181 (96.8%) and 192 (98.0%) participants, respectively. Among 119 matched pairs (238 [68.9%] aged ≥75 years; 177 [74.4%] female), participants had longer composite outcome-free survival at 66 months (mean difference, 6.53 [95% CI, 1.38-11.68] months). Health service-use costs were consistently lower in the participants group, mainly from reduced hospitalizations and long-term care use, with per-person savings of $7688 (95% CI, 1197-14 615) at 66 months, representing a cost:benefit ratio of 8.82. Conclusions and Relevance: In this economic evaluation of a nonrandomized clinical trial, participants in a 24-week multicomponent intervention had longer survival free from death or long-term care eligibility and had lower health service-use costs over 66 months. These findings support consideration of broader implementation of community-based frailty interventions in older adults.