Objective:To assess the effects of intervention measures on the quality control of health examination institutions in Dalian City.Methods:This cross-sectional study encompassed a comprehensive evaluation of 40 physical examination institutions in Dalian City. Interrupted time series analysis was employed to examine the changes in level and slope of processing rates for significant abnormal health examination results, chief inspection physician qualification rates, and completion rates of basic health examination items before (January 2020 to July 2021) and after (August 2021 to July 2022) intervention. An interrupted time series analysis diagram was generated.Results:After the implementation of intervention measures, the processing rate of significant abnormal results in public physical examination institutions reached 93.52%, while the qualification rate of chief inspection physicians was as high as 98.86%. And completion rate of basic health examination items was 93.86%. The rates of handling important abnormal results in health check-ups at private healthcare institutions before intervention, 1 month after intervention, and long-term intervention showed an upward trend of 1.374%, 0.229%, and 0.664%, respectively ( t=8.61, 12.21, and 108.61, all P<0.05). The qualification rate of chief inspection physicians in public physical examination institutions exhibited an increase of 0.227% and 0.155% before and after the intervention respectively ( t=6.74 and 617.67, all P<0.05). The completion rates of basic health check-up items in public healthcare institutions showed an upward trend before intervention, 1 month after intervention, and long-term intervention, with a rate of 0.446%, 0.067%, and 0.745%, respectively ( t=24.95, 3.25, 138.80, all P<0.05). Conclusions:The implementation of quality control intervention measures for health check-ups has significantly improved the quality control of health examination institutions in Dalian City.