Changes over six years in administration of aspirin and beta blockers on arrival and timely reperfusion and in in-hospital and 30-day postadmission mortality in patients with acute myocardial infarction

Abstract

There is conflicting evidence regarding the impact of improving quality-of-care measures on patient outcomes. From July 2002 through June 2008, compliance with 3 in-hospital acute myocardial infarction quality-of-care measures (administration of aspirin and β blockers on arrival, timely reperfusion) and mortality were assessed in consecutive patients eligible for ≥1 of the measures at 8 hospitals (n = 6,826). Adjusted odds ratios for in-hospital and 30-day postadmission mortality and rate ratios for compliance with the 3 quality-of-care measures were calculated using marginal structural models to assess differences over time. Compliance with the 3 in-hospital quality-of-care measures improved significantly over the 6-year period. Adjusted odds ratios (95% confidence intervals) revealed significant decreases in in-hospital mortality in cohorts eligible for aspirin at arrival (year 6 vs baseline 0.37, 0.22 to 0.65), β blockers at arrival (year 6 vs baseline 0.24, 0.11 to 0.52), and an "all-eligible" measure comprising aspirin at arrival, β blockers at arrival, and timely reperfusion (year 6 vs baseline 0.41, 0.24 to 0.69). Significant decreases in 30-day postadmission mortality followed the same pattern (aspirin at arrival 0.53, 0.35 to 0.80; β blockers at arrival 0.43, 0.26 to 0.73; all-eligible measure 0.54, 0.36 to 0.81). In conclusion, over the 6-year study period, the health care system's compliance with the 3 in-hospital quality-of-care measures and 30-day mortality improved significantly.