Adherence to statins, beta-blockers and angiotensin-converting enzyme inhibitors following a first cardiovascular event: a retrospective cohort study

Can J Cardiol. 2005 May 1;21(6):485-8.


Background: Population studies of statin adherence are generally restricted to one to two years of follow-up and do not analyze adherence to other drugs.

Objectives: To report long-term adherence rates for statins, angiotensin-converting enzyme (ACE) inhibitors and beta-blockers in patients who recently experienced a first cardiovascular event.

Methods: Linked administrative databases in the province of Saskatchewan were used in this retrospective cohort study. Eligible patients received a new statin prescription within one year of their first cardiovascular event between 1994 and 2001. Adherence to statins, beta-blockers and ACE inhibitors was assessed from the first statin prescription to a subsequent cardiovascular event.

Results: Of 1221 eligible patients, the proportion of patients adherent to statin medications dropped to 60.3% at one year and 48.8% at five years. The decline in the proportion of adherent patients was most notable during the first two years (100% to 53.7%). Several factors were associated with statin adherence, including age (P = 0.012), number of physician service days (P = 0.037), chronic disease score (P = 0.032), beta-blocker adherence (P < 0.001) and ACE inhibitor adherence (P < 0.001). Adherence to beta-blockers and ACE inhibitors was very similar to adherence to statin medications at each year of follow-up.

Conclusions: Patients who exhibit optimal adherence over one to two years after their initial cardiovascular event generally remain adherent over subsequent years. Also, adherence to beta-blockers and ACE inhibitors is significantly associated with statin adherence in a subset of patients; however, overall adherence to all three drugs was similarly poor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic beta-Antagonists / therapeutic use*
  • Age Factors
  • Angina, Unstable / drug therapy
  • Angioplasty, Balloon, Coronary
  • Angiotensin-Converting Enzyme Inhibitors / therapeutic use*
  • Cohort Studies
  • Coronary Artery Bypass
  • Databases as Topic
  • Drug Prescriptions / statistics & numerical data*
  • Female
  • Humans
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / therapeutic use*
  • Linear Models
  • Male
  • Middle Aged
  • Myocardial Infarction / drug therapy
  • Patient Compliance / statistics & numerical data*
  • Retrospective Studies
  • Saskatchewan
  • Severity of Illness Index
  • Time Factors


  • Adrenergic beta-Antagonists
  • Angiotensin-Converting Enzyme Inhibitors
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors