Adherence to beta-blocker therapy under drug cost-sharing in patients with and without acute myocardial infarction

Am J Manag Care. 2007 Aug;13(8):445-52.


Objective: To evaluate the effects of patient copayment and coinsurance policies on adherence to therapy with beta-adrenergic blocking agents (beta-blockers) and on the rate of initiation of beta-blocker therapy after acute myocardial infarction (MI) in a population-based natural experiment.

Study design: Three sequential cohorts included British Columbia residents age 66 years and older who initiated beta-blocker therapy during time intervals with full drug coverage (2001), a $10 or $25 copayment (2002), and 25% coinsurance (2003-2004). We used linked data on all prescription drug dispensings, physician services, and hospitalizations. Follow-up of each cohort was 9 months after the policy changes.

Methods: We measured the proportion of subjects in each cohort who were adherent to beta-blocker therapy over time, with adherence defined as having >80% of days covered. We also measured the proportion of patients initiating beta-blocker therapy after acute MI. Policy effects were evaluated using multivariable regression.

Results: Adherence to beta-blocker therapy was marginally reduced as a consequence of the copayment policy (-1.3 percentage points, 95% confidence interval [CI] = -2.5 , -0.04) or the coinsurance policy (-0.8 percentage points, 95% CI = -2.0, 0.3). The proportion of patients initiating beta-blockers after hospitalization for acute MI remained steady at about 61% during the study period, similar to that observed in a control population of elderly Pennsylvania residents with full drug coverage.

Conclusions: Fixed patient copayment and coinsurance policies had little negative effect on adherence to relatively inexpensive beta-blocker therapy, or initiation of beta-blockers after acute MI.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acute Disease
  • Adrenergic beta-Antagonists / economics*
  • Adrenergic beta-Antagonists / therapeutic use
  • Aged
  • Aged, 80 and over
  • British Columbia
  • Case-Control Studies
  • Cohort Studies
  • Comorbidity
  • Cost Sharing*
  • Deductibles and Coinsurance
  • Diabetes Complications
  • Female
  • Health Policy / trends
  • Humans
  • Male
  • Medical Record Linkage
  • Myocardial Infarction / drug therapy*
  • Myocardial Infarction / economics
  • Patient Compliance / statistics & numerical data*
  • Prescription Fees*
  • Vascular Diseases


  • Adrenergic beta-Antagonists