Hospital Variation in Use of Secondary Preventive Medicine after Discharge for First Acute Myocardial Infarction during 1995-2004

Objective: To examine temporal trends in hospital use of secondary preventive medicine after discharge for first acute myocardial infarction (AMI) in Denmark. Design: Observational study from national administrative databases of 60,339 patients who survived a first AMI at 73 acute-care hospitals during 1995-2004. Outcome Measures: At least 1 prescription claim for angiotensinconverting enzyme (ACE) inhibitors, β-blockers, or statins within 90 days of discharge for AMI. Findings: The odds ratios between hospitals in the highest and lowest deciles, adjusted for age, gender, period, income, comorbidity, concomitant, and prior pharmaceutical therapy, in 1995 were 8.5 [95% confidence interval (CI), 5.5-12.2] for β-blockers, 3.0 (2.3-3.7) for ACE inhibitors, and 6.2 (4.1-8.8) for statins. By 2004, the hospital variation had decreased for β-blockers (3.2; 2.3-4.0) and statins (4.2; 3.0-5.5) but had increased for ACE inhibitors (3.8; 2.7- 4.9). All the changes over time were significant (P < 0.001). Geographical characteristics of the hospital explained 32% of the variation in use of β-blockers in 2004 and 27% in 1995, 39% of the variation in use of ACE inhibitors in 2004 and 3% in 1995, and 29% of the variation in use of statins and 19% in 1995. Conclusions: Hospital use of secondary preventive medicine after discharge for AMI varied substantially. Hospital variation in use of β-blockers and statins decreased with time whereas variation in use of ACE inhibitors increased. This may be attributed to gradually better agreement for the use of β-blockers and statins and lesser agreement for the use of ACE inhibitors.