Published Online
on April 9, 2007

A more recent version of this article appeared on April 24, 2007

This Article Full Text (PDF) Data Supplement All Versions of this Article: 115/16/2128    most recent CIRCULATIONAHA.106.665992v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schneeweiss, S. Articles by Glynn, R. J. Search for Related Content PubMed PubMed Citation Articles by Schneeweiss, S. Articles by Glynn, R. J. Related Collections Health policy and outcome research Primary prevention Secondary prevention Related Article

Submitted on September 20, 2006
Accepted on February 1, 2007

Adherence to Statin Therapy Under Drug Cost Sharing in Patients With and Without Acute Myocardial Infarction. A Population-Based Natural Experiment

Sebastian Schneeweiss MD, ScD^*, Amanda R. Patrick MS, Malcolm Maclure ScD, Colin R. Dormuth ScD, and Robert J. Glynn PhD, ScD

From the Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine (S.S., A.R.P., C.R.D., R.J.G.) and Division of Preventive Medicine (R.J.G.), Brigham and Women’s Hospital, Harvard Medical School, Boston, Mass; Department of Epidemiology (S.S., M.M.) and Department of Biostatistics (R.J.G.), Harvard School of Public Health, Boston, Mass; and Department of Health Information Sciences (M.M.), University of Victoria, British Columbia, Canada.

^* To whom correspondence should be addressed. E-mail: schneeweiss{at}post.harvard.edu.

Background--As medication spending grows, Medicare Part D will need to adapt its coverage policies according to emerging evidence from a variety of insurance policies. We sought to evaluate the consequences of copayment and coinsurance policies on the initiation of statin therapy after acute myocardial infarction and adherence to therapy in statin initiators using a natural experiment of all British Columbia residents aged 66 years and older.

Methods and Results--Three consecutive cohorts that included all patients who began statin therapy during full drug coverage (2001), coverage with a $10 or $25 copay (2002), and coverage with a 25% coinsurance benefit (2003-2004) were followed up with linked healthcare utilization data (n=51 561). Follow-up of cohorts was 9 months after each policy change. Adherence to statin therapy was defined as 80% of days covered. Relative to full-coverage policies, adherence to new statin therapy was significantly reduced, from 55.8% to 50.5%, under a fixed copayment policy (-5.4% points; 95% CI, -6.4% to -4.4%) and the subsequent coinsurance policy (-5.4% points; 95% CI, -6.3% to -4.4%). An uninterrupted increase in the proportion of patients initiating statin therapy after an acute myocardial infarction (1.7% points per quarter) was observed over the study period, similar to a Pennsylvania control population with full coverage. Sudden changes to full out-of-pocket spending, similar to Medicare’s Part D "doughnut hole," almost doubled the risk of stopping statins (adjusted odds ratio, 1.94, 95% CI, 1.82 to 2.08).

Conclusions--Fixed patient copayment and coinsurance policies have negative effects on adherence to statin lipid-lowering drug therapy but not on their initiation after myocardial infarction.

Key words: statins • health care costs • drugs • economics, pharmaceutical

Related Article:

Issue Highlights
Circulation 2007 115: 2087. [Extract] [Full Text]

This article has been cited by other articles:

				P. M. Ho, C. L. Bryson, and J. S. Rumsfeld Medication Adherence: Its Importance in Cardiovascular Outcomes Circulation, June 16, 2009; 119(23): 3028 - 3035. [Abstract] [Full Text] [PDF]

				M. A. Hlatky and P. A. Heidenreich The Year in Epidemiology, Health Services Research, and Outcomes Research J. Am. Coll. Cardiol., April 21, 2009; 53(16): 1459 - 1466. [Full Text] [PDF]

				J. D. Piette Cost-Related Medication Underuse: A Window Into Patients' Medication-Related Concerns Diabetes Spectr, April 1, 2009; 22(2): 77 - 80. [Abstract] [Full Text] [PDF]

				S. Schneeweiss, A. R. Patrick, A. Pedan, L. Varasteh, R. Levin, N. Liu, and W. H. Shrank The Effect Of Medicare Part D Coverage On Drug Use And Cost Sharing Among Seniors Without Prior Drug Benefits Health Aff., March 1, 2009; 28(2): w305 - w316. [Abstract] [Full Text] [PDF]

				N. K. Choudhry Copayment Levels and Medication Adherence: Less Is More Circulation, January 27, 2009; 119(3): 365 - 367. [Full Text] [PDF]

				J. A. Doshi, J. Zhu, B. Y. Lee, S. E. Kimmel, and K. G. Volpp Impact of a Prescription Copayment Increase on Lipid-Lowering Medication Adherence in Veterans Circulation, January 27, 2009; 119(3): 390 - 397. [Abstract] [Full Text] [PDF]

				G. H. Gislason, J. N. Rasmussen, S. Z. Abildstrom, T. K. Schramm, M. L. Hansen, P. Buch, R. Sorensen, F. Folke, N. Gadsboll, S. Rasmussen, et al. Persistent Use of Evidence-Based Pharmacotherapy in Heart Failure Is Associated With Improved Outcomes Circulation, August 14, 2007; 116(7): 737 - 744. [Abstract] [Full Text] [PDF]