Strengthening China's National Essential Public Health Services Package for hypertension and diabetes care: protocol for an interrupted time series study with mixed-methods process evaluation and health economic evaluation

Background: Despite major primary health care (PHC) reforms in China with the 2009 launch of the National Essential Public Health Service Package, the country experiences many challenges in improving the management of non-communicable diseases in PHC facilities. "EMERALD" is a multifaceted implementation strategy to strengthen the management of hypertension and type-2 diabetes mellitus (T2DM) in PHC facilities. The study aims to: (1) examine the effectiveness of EMERALD in improving hypertension and T2DM management; (2) evaluate the implementation of the interventions; and (3) use the study findings to model the long-term health economic impact of the interventions. Methods: The EMERALD intervention components include: (1) empowerment for PHC providers through training and capacity building; (2) empowerment for patient communities through multi-media health education; and (3) empowerment for local health administrators through health data monitoring and strengthening governance of local PHC programs. An interrupted time series design will be used to determine the effectiveness of the interventions based on routinely collected health data extracted from local health information systems. The primary effectiveness outcome is the guideline-recommended treatment rates for people with hypertension and T2DM. Secondary effectiveness outcomes include hypertension and T2DM diagnosis and control rates, and enrolment and adherence rates to the recommended care processes in the National Essential Public Health Service Package. A mixed-methods process evaluation will be conducted to evaluate the implementation of the interventions, including the reach of the target population, adequacy of adoption, level of implementation fidelity, and maintenance. Qualitative interviews with policy makers, health administrators, PHC providers, and patients with hypertension and/or T2DM will be conducted to further identify factors influencing the implementation. In addition, health economic modelling will be performed to explore the long-term incremental costs and benefits of the interventions. Discussion: This study is expected to generate important evidence on the effectiveness, implementation, and health economic impact of complex PHC interventions to strengthen the primary care sector's contribution to addressing the growing burden of non-communicable diseases in China. Trial registration: The study has been registered on Chinese Clinical Trial Registry at https://www.chictr.org.cn/ (Registration number ChiCTR2400082036, on March 19th 2024).