Assessing overall duration of cardiovascular medicines in veterans with established cardiovascular disease
Received 13 April 2009; accepted 3 June 2009.
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), β-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 β-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.
aQuality Use of Medicines and Pharmacy Research Centre, Sansom Institute, University of South Australia
bData Management and Analysis Centre, Discipline of Public Health, University of Adelaide, Australia
Correspondence to Associate Professor Elizabeth E. Roughead, PhD, Quality Use of Medicines and Pharmacy Research Centre, Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, Frome Road, GPO Box 2471, Adelaide, South Australia 5001, Australia Tel: +61 8 8302 1233; fax: +61 8 8302 1087;
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