Effect of multicomponent exercise intervention on multidimensional frailty in older adults with mild cognitive impairment: a secondary analysis of the MIND-STEP randomised clinical trial

BACKGROUND: Frailty is common among older adults with mild cognitive impairment (MCI) and encompasses physical, cognitive, psychological and social domains, yet randomised evidence on theory-informed multicomponent exercise interventions targeting multidimensional frailty remains limited. This secondary analysis of the MIND-STEP RCT evaluated intervention effects across frailty domains. METHODS: MIND-STEP was a single-blind, parallel-group RCT conducted in nursing homes in China. Participants were randomised (1:1) to a 12-week group-based multicomponent exercise programme incorporating peer interaction and self-efficacy strategies, or to usual care. Eligible participants were adults with MCI aged ≥60 years who did not engage in regular physical exercise. Frailty domains, including physical, cognitive, psychological, social and multidimensional, were assessed at baseline, 6, 12 and 24 weeks. Generalised estimating equations within a difference-in-differences framework were used to estimate between-group risk differences. FINDINGS: Among 156 randomised participants [mean age, 69.19 years; 108 women (69.23%)], baseline prevalence was 19.23% for physical/cognitive frailty, 27.56% psychological frailty, 56.41% social frailty and 51.28% multidimensional frailty. At 12 weeks, the intervention group showed greater reductions than usual care in physical frailty (RD = -13.23%; 95% CI: -21.68% to -4.78%; P = .002), psychological frailty (RD = -13.87%; 95% CI: -25.04% to -2.69%; P = .015), cognitive frailty (RD = -18.98%; 95% CI: -28.17% to -9.79%; P < .001), and multidimensional frailty (RD = -17.79%; 95% CI: -29.21% to -6.36%; P = .002), whereas social frailty did not differ between groups. Reductions were also observed at 24-week follow-up within the study period, particularly for cognitive frailty. INTERPRETATION: In older adults with MCI, a theory-informed multicomponent exercise programme incorporating peer interaction and self-efficacy strategies was associated with improvements across multiple frailty domains at 12 weeks. Improvements were maintained at 24-week within the study period. These findings suggest a promising approach for addressing multidimensional frailty in this population, although longer-term effects require further investigation.