Variation in initiating secondary prevention after myocardial infarction by hospitals and physicians, 1997 through 2004

PURPOSE: Myocardial infarction (MI) survivors benefit from receiving secondary prevention, including beta-blockers, angiotensin-blocking agents, and statins, as recommended by guidelines. Compliance with these guidelines is suboptimal. We sought to describe the initiation of secondary prevention in MI survivors, and to describe the variation in initiation by discharging the hospital, the physician, and the physician "responsible" for secondary prevention prescribing decisions in British Columbia in 1997-2004. METHODS: We assembled a cohort of 28,613 patients discharged alive from the hospital after their first MI and were not readmitted within 30 days. Physicians responsible for prescribing post-MI secondary prevention medications were identified as the physicians prescribing the greatest number of cardiac medications (post-discharge cardiac prescribers). We used multilevel logistic regression to assess the variation in drug initiation at discharging hospital, discharging physician, and post-discharge cardiac prescriber levels, which were adjusted for patient and provider characteristics during the study period. RESULTS: Beta-blockers initiation increased from 56 to 71% over the 8-year study period; angiotensin-converting enzyme/angiotensin II receptor blocker initiation increased from 37 to 70%, and statin initiation increased from 22 to 66% (0-28% for high-potency statins). The probability for initiating an average patient with the study drugs varied widely in age-sex-adjusted models at the hospital and physician levels. Further adjustment did not meaningfully change findings. The variation was largest for statins. The maximum between-provider variance was found for high-potency statins in 2003-2004 at the post-discharge cardiac prescriber level. CONCLUSIONS: Study-drug initiation is increasing among MI survivors, but the variation in initiation is wide between discharging hospitals and physicians.