Development and feasibility of a theory-driven multidomain intervention for community-dwelling older adults with mild cognitive impairment: a quasi-experimental pilot study based on the Multi-Theory Model

Abstract Background Mild cognitive impairment (MCI) is a critical stage for dementia prevention, and multidomain interventions are recommended to delay cognitive decline. However, implementing these interventions in community settings remains challenging because of difficulties in initiating health behaviours and maintaining long-term adherence. Theory-based interventions can facilitate the initiation of behaviors and sustained engagement. This study aimed to develop a multidomain intervention guided by the Multi-Theory Model (MTM) for community-dwelling older adults with MCI and to evaluate its feasibility and preliminary effectiveness. Methods This study comprised two sequential phases: intervention development and feasibility evaluation. The intervention was developed through evidence synthesis, semi-structured interviews with older adults with MCI guided by the Multi-Theory Model (MTM), and multidisciplinary expert consultation. A 12-week quasi-experimental pilot study with a historical non-equivalent control group was subsequently conducted. Participants in the control group (n = 20) received a conventional multidomain intervention, whereas those in the intervention group (n = 22) received the MTM-guided multidomain intervention. Feasibility outcomes included recruitment and adherence. The primary outcome was feasibility, assessed by recruitment and adherence. Secondary outcomes included cognitive function, physical performance, frailty, depressive symptoms, instrumental activities of daily living, and social participation. Results Forty participants completed the study (intervention, n = 21; control, n = 19). Recruitment was significantly higher in the intervention group than in the control group (73.3% vs. 40.0%, P = 0.024), and overall adherence was also significantly better (P = 0.007). Compared with the control group, participants receiving the MTM-guided intervention demonstrated significantly greater improvements in global cognitive function, physical performance, instrumental activities of daily living, and social participation (all P < 0.05), together with greater reductions in frailty and depressive symptoms (both P < 0.001). Conclusions The MTM-guided multidomain intervention was feasible and acceptable for community-dwelling older adults with MCI, with higher recruitment and adherence than a conventional programme. These findings suggest that integrating behaviour change strategies that explicitly target behaviour initiation and maintenance may facilitate the implementation of multidomain interventions in community settings. Larger multicentre randomised controlled trials with longer follow-up are warranted to confirm the intervention's effectiveness and scalability. Trial registration This study was registered with the Chinese Clinical Trial Registry (ChiCTR2500112119; registered on 10 November 2025. https://www.chictr.org.cn/showproj.html?proj=289572).