Clinical Research Hospital- and Patient-Level Analysis of Quality Indicators in Acute Coronary Syndrome Care: A Nationwide Database Study

Background: This study aimed to clarify the variations in the quality of care provided to patients with acute coronary syndrome (ACS) and to investigate the association between quality of care and mortality at both hospital and patient levels with the use of a nationwide database. Methods: Patients with ACS who underwent percutaneous coronary intervention (PCI) from April 2014 to March 2018 were included from the National Database of Health Insurance Claims and Specific Health Checkups of Japan. Twelve quality indicators (QIs) available from administrative data and the association of the QIs with all-cause mortality were investigated. Results: From the analysis of 216,436 patients from 1215 hospitals, adherence to PCI on admission day, aspirin use on arrival, P2Y12 in-hibitor use, and left ventricular function assessment were high (me-dian proportion > 90%), and adherence to outpatient cardiac rehabilitation was low (median proportion < 10%). At the hospital level, acute-phase composite QI score was associated with reduced risk-adjusted 30-day mortality (b = -0.92 [95% confidence interval -1.19 to -0.65]; P < 0.001). At the patient level, all acute-phase and subacute-phase QIs were inversely associated with 30-day and 2-year mortalities, respectively (all P < 0.001). Conclusions: Substantial variations in ACS care were observed in the current nationwide database. High adherence to the QI sets was associated with significant survival gains at both hospital and patient levels. Multilevel approach in QI assessment may be effective for improvement of survival in this population.