Abstract
BACKGROUND: The increasing prevalence of multimorbidity represents a significant public health challenge, particularly in an ageing global population. This is particularly evident in patients with type 2 diabetes mellitus (T2DM), yet the management of lifestyle factors remains suboptimal. The objective of this study was to evaluate the efficacy, feasibility and cost-effectiveness of proactive health behaviour intervention strategies based on digital health technology and the multi-theory model at the primary care level. METHODS: A cluster randomised controlled trial with a 24-month follow-up period will be conducted to evaluate the effectiveness of the proactive health behaviour intervention strategies. The strategies comprises three components, including free multi-sign monitoring bracelets and a mobile application, proactive health behaviour education delivered via short video format, and goal setting and support through shared decision-making. These elements can be readily integrated into routine outpatient practice. A minimum of 420 older T2DM patients with multimorbidity and exhibiting suboptimal proactive health behaviours will be recruited from 14 primary healthcare centres (PHCs) and randomly assigned on a PHC basis. The primary outcomes will be whether the participants have achieved at least one goal at six months, whether they have achieved glycemic control, and their cardiometabolic health scores at six months. The effectiveness of the intervention strategies will be assessed using the intention-to-treat dataset and mixed effect models. Additionally, implementation assessments and cost-effectiveness analyses will be conducted. Ethical approval for the protocol was obtained from the Ethics Committee of Shanghai East Hospital (No. 2024YS-083). DISCUSSION: This article presents the methodology of a pragmatic cluster randomised controlled trial utilising a hybrid effectiveness-implementation type 2 design. The objective is to assess the potential applicability of the proactive health behaviour intervention strategies in primary care for older T2DM patients with multimorbidity. TRIAL REGISTRATION: The study protocol has been registered prospectively in the Chinese Clinical Trial Registry (ChiCTR2400088374, assigned on 16/08/2024). Recruitment is ongoing at the time of manuscript submission. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12875-026-03216-6.