Clinical InvestigationAcute Ischemic Heart DiseasePatient adherence to generic versus brand statin therapy after acute myocardial infarction: Insights from the Can Rapid Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the American College of Cardiology/American Heart Association Guidelines Registry
Section snippets
Data sources
We used data from the CRUSADE study, which was a national observational inpatient registry conducted from 2001 to 2006 with the goal of improving quality of care through promoting evidence-based treatment for patients with unstable angina and NSTEMI. The years during which the CRUSADE study was conducted encompass a period where both generic and brand statins were available, in addition to the period directly after publication of the PROVE IT–TIMI 22 trial, which demonstrated superiority of a
Results
Of 1,421 NSTEMI patients aged >65 years, 931 (65.5%) received brand statin therapy, whereas 490 (34.5%) received generic statin therapy. Patients who received brand statins were similar to those who received generic statins with regard to age, gender, and race (Table I). The distribution of medical comorbidities was generally similar across brand and generic statin groups. Patients who received generic statins also had similar values of high-density lipoprotein cholesterol, low-density
Discussion
We evaluated 1-year adherence rates among generic and brand name statin users in a cohort of older NSTEMI patients from a geographically diverse sample. Our major findings are as follows: (1) overall, adherence to statins at 1 year was suboptimal for all patients with >40% of patients not having optimal adherence (PDC >80%) and (2) use of a generic statin was not associated with higher 1-year adherence in either unadjusted or adjusted models.
Our results showing suboptimal adherence to statin
Limitations
Our study had several limitations. First, despite adjustment for detailed clinical and socioeconomic data, we cannot exclude the possibility of residual confounding. Second, although the PDC has been previously validated as a metric of adherence, it is a representation of prescription fills—not medication-taking behavior. Third, this study was primarily conducted before the widespread introduction of $4 generic programs, which were launched in late 2006; however, it is still possible that some
Conclusions
In a cohort of older NSTEMI patients enrolled in Medicare Part D, we found that overall adherence to statin therapy to 1 year was suboptimal, but we did not find evidence of improved adherence among patients prescribed generic versus brand statins. Future work assessing reasons for suboptimal statin adherence and associations between medication use patterns and long-term outcomes in cardiovascular disease populations is needed.
Conflict of interest disclosures
EC O'Brien: Dr O'Brien reports that she has received research funding from Merck. LM McCoy: Ms McCoy has no relevant disclosures to report. LE Thomas: Dr Thomas has no relevant disclosures to report. ED Peterson: Dr Peterson reports research funding from Eli Lilly & Company; Ortho-McNeil-Janssen Pharmaceuticals, Inc; Society of Thoracic Surgeons; American Heart Association; American College of Cardiology (all significant); consulting for AstraZeneca; Boehringer Ingelheim; Genentech; Johnson &
Acknowledgements
We thank the staff and participants of the CRUSADE Registry for their important contributions to this work.
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John K French, MB, PhD served as guest editor for this article.
Sources of funding: CRUSADE was funded by Millennium Pharmaceuticals, Schering-Plough Corporation, and the Bristol-Myers Squibb/Sanofi Pharmaceuticals Partnership. This work was supported internally by the Duke Clinical Research Institute, which donated support for these analyses. The authors would like to thank Erin Hanley, MS (Duke Clinical Research Institute), for editorial assistance and article preparation. She did not receive compensation for her assistance apart from her employment at the institution where the study was conducted.