Factors Associated With Regional Differences in Healthcare Quality for Patients With Acute Myocardial Infarction in Japan

ABSTRACT Objectives Regional medical coordination is essential for health-system reform in Japan, and the quality of healthcare at the regional level is of great interest. Regional differences in the quality of healthcare for cardiovascular diseases have been pointed out in previous research, and we aimed to clarify regional factors that influence the quality. Design Insurance claims database study. Setting Patients of acute care in Japan. Participants Japanese patients included in the national Diagnosis Procedure Combination (DPC) databases who admitted to hospitals with diagnosis of acute myocardial infarction (AMI) from April 2016 to March 2019. Main outcome and measures Using the national DPC databases, risk-adjusted mortality (RAM) in each secondary medical area (SMA) was derived as an indicator for the quality of the healthcare for patients with AMI. Factors associated with RAM were analysed using the partial least squares (PLS) regression model. Results There is a wide variation in RAM in the SMAs; the maximum value was 0.593 and the minimum value was 1.445. The PLS regression identified two components positively correlated with RAM. The first component (Component 1) positively correlates with the proportion of the elderly within the population and negatively correlates with the number of medical facilities per area, the population density, and the intra-SMA access to centres with a high volume of emergency percutaneous coronary interventions (ePCI). The second component (Component 2) positively correlates with the number of medical facilities per area and negatively correlates with the number of physicians per person and the intra-SMA access to centres with a high volume of ePCI. Conclusion There was wide regional variation in the quality of in-hospital AMI treatments. Results suggested the degree of rurality, the sufficiency of medical resources, the access to high-volume ePCI centres, and coordination of healthcare delivery were associated with healthcare quality for AMI patients.