Association between hospital process performance and outcomes among patients with acute coronary syndromes

Context  Selected care processes are increasingly being used to measure hospital quality; however, data regarding the association between hospital process performance and outcomes are limited. Objectives  To evaluate contemporary care practices consistent with the American College of Cardiology/American Heart Association (ACC/AHA) guideline recommendations, to examine how hospital performance varied among centers, to identify characteristics predictive of higher guideline adherence, and to assess whether hospitals' overall composite guideline adherence was associated with observed and risk-adjusted in-hospital mortality rates. Design, Setting, and Participants  An observational analysis of hospital care in 350 academic and nonacademic US centers of 64 775 patients enrolled in the CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the ACC/AHA Guidelines) National Quality Improvement Initiative between January 1, 2001, and September 30, 2003, presenting with chest pain and positive electrocardiographic changes or cardiac biomarkers consistent with non–ST-segment elevation acute coronary syndrome (ACS). Main Outcome Measures  Use of 9 ACC/AHA class I guideline-recommended treatments and the correlation among hospitals' use of individual care processes as well as overall composite adherence rates. Results  Overall, the 9 ACC/AHA guideline-recommended treatments were adhered to in 74% of eligible instances. There was modest correlation in hospital performance among the individual ACS process metrics. However, composite adherence performance varied widely (median interquartile range] composite adherence scores from lowest to highest hospital quartiles, 63% 59%-66%] vs 82% 80%-84%]). Composite guideline adherence rate was significantly associated with in-hospital mortality, with observed mortality rates decreasing from 6.31% for the lowest adherence quartile to 4.15% for the highest adherence quartile (P<.001). After risk adjustment, every 10% increase in composite adherence at a hospital was associated with an analogous 10% decrease in its patients' likelihood of in-hospital mortality (adjusted odds ratio, 0.90; 95% confidence interval, 0.84-0.97; P<.001). Conclusion  A significant association between care process and outcomes was found, supporting the use of broad, guideline-based performance metrics as a means of assessing and helping improve hospital quality.