Payment reform, remuneration incentives, and changes in service utilization and institutional revenue composition: an interrupted time-series analysis from Sanming, China

Hospital-centred service delivery and underused primary care can reduce health-system efficiency. We examined changes in service utilization, provider distribution, and institutional revenue composition during Sanming’s health reform. We analysed 144 monthly observations from January 2013 to December 2024 using a single-group segmented interrupted time-series design with interruptions in August 2015, January 2018, and October 2021. Only genuinely missing values were model-imputed; observed zero and statistically extreme values were retained. Newey-West standard errors used a three-month lag, with alternative lags and seasonal specifications assessed in sensitivity analyses. The design did not include a comparison area. Mean monthly primary care outpatient and emergency visits increased from 160,018 in 2013 to 516,885 in 2024, while the primary care visit share increased from 27.5% to 47.7%. After August 2015, the monthly trends in total visits and primary care visits increased by 8,451 (95% CI 4,773 to 12,129) and 7,284 (95% CI 3,820 to 10,747), respectively, and the primary care visit-share trend increased by 0.442% points (95% CI 0.245 to 0.640; all P < 0.001). After January 2018, trends in inpatient admissions, total visits, provider-specific visits, the hospitalization rate, and the primary care visit share declined. After October 2021, the primary care visit-share trend increased, while later-stage inpatient findings were attenuated after COVID-19 adjustment. Results were broadly stable across transition-window, lag-order, and seasonal-specification analyses. Successive reform stages in Sanming were associated with changes in service utilization, provider distribution, and institutional revenue composition. These temporal associations are consistent with, but do not demonstrate, a role for aligned payment accountability, remuneration arrangements, and primary care capacity.