Frailty and cognitive impairment are major challenges in aging populations. Multidomain interventions targeting physical, cognitive, and nutritional health show promise; however, evidence on rural-urban differences in efficacy remains limited.

To evaluate the impact of rural-urban disparities on the clinical efficacy of a 12-month multidomain intervention for cognitive and physical outcomes in older adults.

Cluster-randomized controlled trial.

Community clusters in five cities/counties across Taiwan.

A total of 1,082 adults aged ≥65 years from 40 community clusters were randomized to intervention or control groups.

The intervention group received a 12-month program including physical exercise (45 minutes/session), cognitive training (1 hour/session), and nutritional guidance (15 minutes/session). The control group received telephone-based health education. This trial was registered at ClinicalTrials.gov (NCT03056768)

Outcomes included walking speed, grip strength, physical activity (METs), frailty (CHS score), and cognitive function (MoCA), assessed at baseline, 6, and 12 months.

Urban participants showed significantly greater gains in visuospatial/executive function at the 12 month (rural-urban difference 0.63, 95% CI: 0.26 -1.03), and walking speed at the 12 month (rural-urban difference 0.12 m/s, 95% CI: 0.05 – 0.19). Rural participants demonstrated better improvements in grip strength at the 12 month (rural-urban difference -2.59 kg, 95% CI: -3.91 - -1.27) and language function (rural-urban difference -0.38, 95% CI: -0.68 - -0.09). Frailty reduction was more pronounced in urban areas at the 12 month (−0.21, 95% CI: -0.38 - -0.03, p = 0.025), but showed minimal change in the rural participants.

Rural-urban disparities influence the effectiveness of multidomain interventions. Tailored strategies are needed to optimize health outcomes across diverse settings.