Tailored implementation of multidomain intervention to prevent cognitive impairment in community-dwelling older adults (Timi-Cog): A study protocol for a hybrid type 2 trial effectiveness-implementation study.

Abstract

Background & objectives: Despite growing recognition of multidomain non-pharmaceutical interventions (NPIs) for preventing cognitive impairment, their scalable implementation remains underdeveloped in China. This hybrid type 2 effectiveness-implementation study aims to bridge this gap by identifying implementation determinants, developing tailored strategies, and evaluating both implementation or health outcomes for multidomain NPIs and tailored strategies.

Methods: This protocol describes the design of an ongoing study. The formative phase has been completed: guided by Consolidated Framework for Implementation Research (CFIR), we integrated the COM-B model from the Behaviour Change Wheel (BCW) and the Theoretical Domains Framework (TDF) into an interview guide. Key informant interviews and focus groups identified barriers/facilitators, and the CFIR-ERIC matching tool finalized the implementation strategies. Subsequently, a hybrid type 2 cluster RCT will be conducted (or is currently underway) across 13 districts in Changxing County, Zhejiang. A total of 1170 older adults and 273 community health workers (CHWs) - including general practitioners, social workers, and volunteers - will be randomized into three study arms: Arm 1 will receive evidence-based practices (EBP) combined with intrinsic motivation; Arm 2, EBP with implementation strategies; and Arm 3 (control), health education with implementation strategies. The EBP package includes cardio-metabolic risk management, cognitive training, physical activity, and nutritional counseling. Implementation uses three bundles: (1) Capacity Building and Professional Support, (2) Collaborative Implementation and Network Building, and (3) an AI-enabled WeChat mini-program (Timi-Cog). Outcomes will be assessed using the Re-AIM framework over 18 months. Statistical analysis will employ mixed-effects linear models, adjusted for baseline characteristics and clustering effects.

Conclusions & implications: This theory-informed initiative addresses the dementia prevention implementation gap in China. By combining BCW/TDF frameworks with implementation science methods and employing a hybrid design, the study will generate robust evidence on both clinical effectiveness and practical implementation, informing the integration of multidomain NPIs into China's primary care system.

Trial registration: Chinese Clinical Trial Registry (ChiCTR2500098587).