Background: This study aimed to determine persistence, adherence, and time without therapy with cardiovascular medicines over all episodes of use among veterans following hospitalization for ischemic heart disease.
Methods: Retrospective cohort study using Department of Veterans' Affairs database including 9635 veterans with a hospitalization for acute myocardial infarction, angina, or ischemic heart disease, and who had been dispensed cardiovascular medicines in the 3 months posthospitalization. The main outcome measures were duration of first treatment episode, duration of overall treatment episode, and adherence with recommended therapies: angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), lipid-lowering therapy, calcium channel blockers (CCBs), beta-blockers, and antiplatelet therapy.
Results: The median duration of overall treatment was 6.2 years [95% confidence interval (CI): 6.0-6.4] for lipid-lowering therapy, 5.4 years (95% CI: 5.1-5.5) for ACE inhibitors/ARBs, 5.0 years (95% CI: 4.8-5.1) for antiplatelets, 3.4 years (95% CI: 3.3-3.6) for beta-blockers, and 2.8 years (95% CI: 2.6-3.0) for CCBs. Adherence was 72% for CCBs, 75% for ACE inhibitors/ARBs, 84% for lipid-lowering therapy, and 84% for antiplatelets other than aspirin. The median time without therapy was 4.5 months or less for ACE inhibitors/ARBs, antiplatelets, and lipid-lowering therapy.
Conclusion: Problems with medication adherence can relate to either persistence or compliance during treatment. This novel method provides a way to determine which of these factors is most problematic when considering chronic therapies. We found that Australian veterans with established cardiovascular disease are persistent with their cardiovascular therapy, with only small gaps in therapy.