Association of long-term adherence to evidence-based combination drug therapy after acute myocardial infarction with all-cause mortality. A prospective cohort study based on claims data

Abstract

To determine long-term adherence to evidence-based secondary preventive combination pharmacotherapy in survivors of acute myocardial infarction (AMI) and to investigate the association between adherence to recommended therapy and all-cause mortality in claims data. Prospective cohort study based on claims data of an 18.75% random sample of all persons insured with the local statutory health insurance fund AOK Hesse. Study population included patients with hospital discharge diagnoses of AMI between 2001 and 2005 excluding those who died within the first 30days after AMI or who had been hospitalised with an AMI in the previous 2years. A total of 3,008 patients were followed up until death, cancellation of insurance, or the end of the study period on 31 December 2007, whichever came first (median follow-up: 4.2years). Drug adherence to single drug groups as determined by proportion of days covered ≥80% was 21.8% for antiplatelet drugs, 9.4% for beta-blockers, 45.6% for ACE inhibitors or angiotensin II receptor blockers and 45.1% for lipid-lowering drugs. A total of 924 (39.7%) patients met our definition of guideline adherence: Drugs available from three of four relevant drug groups on the same day for at least 50% of the observation time. Of the patients adhering to the guidelines, 17.3% died and of the non-adherents, 32.4% died. All-cause mortality was 28% lower for guideline-adherent patients than for the non-adherent group (adjusted HR 0.72, 95% CI 0.60-0.86). In everyday practice, post AMI patients benefit from guideline-oriented treatment, but the percentage of adherent patients should be improved.