Strengthening the continuum of care and multisectoral action for non-communicable diseases in Chamarajanagar district, India: an implementation research protocol (IMPACT NCD).

BACKGROUND: Non-communicable diseases (NCDs), particularly hypertension and diabetes, represent a rising public health burden in India, driven by lifestyle changes and complex social determinants. In Karnataka's Chamarajanagar district, previous research identified a high NCD prevalence alongside systemic gaps in the continuum of care and multisectoral action. The IMPACT NCD project is an implementation research study that aims to strengthen the primary healthcare system's capacity and foster multisectoral collaboration for effective NCD prevention and management. Its primary scientific objective is to conduct a rigorous implementation evaluation. This evaluation examines the causal pathways and contextual factors that influence the success of these real-world interventions to understand what works, for whom, and why. METHODOLOGY: The study is guided by a theory-driven implementation research design. Interventions, developed using a participatory approach, include two main components: Capacity building and technical support for healthcare workers at Ayushman Arogya Mandirs (AAMs) on NCD screening, follow-up, and the continuum of care. Sensitisation workshops for local elected officials, police personnel, and students in grades 8 to 12. The effectiveness of these strategies will be evaluated using a sequential mixed-methods approach to understand the pathways and mechanisms of change. First, quantitative program data will be analysed using Principal Component Analysis (PCA) and cluster analysis to stratify primary units by performance. Subsequently, a purposive sample of high-performing and low-performing units will be selected for in-depth qualitative analysis through interviews and observations to test and refine the project's Theory of Change. DISCUSSION: The project's strong focus on implementation evaluation is critical. By moving beyond simply measuring outcomes to understanding the underlying processes and contextual factors, the study aims to identify mechanisms that drive implementation success and sustainability mechanisms of change, the study will generate crucial insights into how complex, multisectoral NCD programs can be effectively embedded within existing government systems.