Association of evidence-based care processes and outcomes among patients with acute coronary syndromes: performance matters.

The American College of Cardiology and American Heart Association publishes evidence-based guideline recommendations, yet the degree to which these guidelines are followed and the association between hospital guideline adherence and patient outcomes are unknown. Using data from 350 US centers participating in the "Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the American College of Cardiology/American Heart Association Guidelines" Quality Improvement Initiative, we evaluated the in-hospital treatment and outcomes from 64,775 patients with non-ST-segment elevation acute coronary syndromes. Overall, guideline-recommended treatments were followed in 74% of eligible instances. However, hospitals varied considerably in their composite adherence rates (median lowest to highest adherence hospital quartiles 63% to 82%). We also noted significant age, gender, and racial disparities in the use of guideline-recommended therapies as well as significant facility type and regional variability in care. Composite guideline adherence rates were significantly associated with in-hospital mortality. After risk adjustment, every 10% increase in composite adherence at a hospital was associated with a 10% reduction in its patients' likelihood of in-hospital mortality. Our findings support the use of broad, guideline-based performance metrics as a means of assessing and helping improve hospital quality.