Adherence With Statin Therapy in Elderly Patients With and Without Acute Coronary Syndromes

Jackevicius, Cynthia A. BScPhm, MSc, FCSHP
Mamdani, Muhammad PharmD, MA, MPH
Tu, Jack V. MD, PhD, FRCPC

Department of Health Policy, Management, and Evaluation (Ms Jackevicius and Drs Mamdani and Tu), Department of Medicine (Dr Tu), Pharmacy Department and Women's Health Program, University Health Network-Toronto General Hospital; Institute for Clinical Evaluative Sciences (Ms Jackevicius and Drs Mamdani and Tu), University of Toronto; and Division of General Internal Medicine, Sunnybrook and Women's College Health Sciences Centre (Dr Tu), Toronto, Ontario.

Corresponding Author and Reprints: Cynthia A. Jackevicius, BScPhm, MSc, FCSHP, Pharmacy Department, Toronto General Hospital, 200 Elizabeth St, Toronto, Ontario, Canada M5G 2C4 (e-mail: [email protected]).

Financial Disclosure: Ms Jackevicius receives honoraria for continuing education from Merck, Pfizer, and Bayer.

Author Contributions:Study concept and design: Jackevicius, Mamdani.

Acquisition of data: Mamdani.

Analysis and interpretation of data: Jackevicius, Mamdani, Tu.

Drafting of the manuscript: Jackevicius.

Critical revision of the manuscript for important intellectual content: Jackevicius, Mamdani, Tu.

Statistical expertise: Jackevicius, Mamdani.

Obtained funding: Tu.

Administrative, technical, or material support: Jackevicius.

Study supervision: Tu.

Funding/Support: This study was supported by an operating grant to the Canadian Cardiovascular Outcomes Research Team from the Canadian Institutes of Health Research and the Heart and Stroke Foundation. Dr Tu is supported by a Canada Research Chair in Health Services Research.

Disclaimer: The results and conclusions are those of the authors and should not be attributed to any of the sponsoring agencies.

JAMA: The Journal of the American Medical Association 288(4):p 462-467, July 24/31, 2002.

Context

Landmark clinical trials have demonstrated the survival benefits of statins, with benefits usually starting after 1 to 2 years of treatment. Research prior to these trials of older lipid-lowering agents demonstrated low levels of 1-year adherence.

Objective

To compare 2-year adherence following statin initiation in 3 cohorts of patients: those with recent acute coronary syndrome (ACS), those with chronic coronary artery disease (CAD), and those without coronary disease (primary prevention).

Design and Setting

Cohort study using linked population-based administrative data from Ontario.

Patients

All patients aged 66 years or older who received at least 1 statin prescription between January 1994 and December 1998 and who did not have a statin prescription in the prior year were followed up for 2 years from their first statin prescription. There were 22 379 patients in the ACS, 36 106 in the chronic CAD, and 85 020 in the primary prevention cohorts.

Main Outcome Measures

Adherence to statins, defined as a statin being dispensed at least every 120 days after the index prescription for 2 years.

Results

Two-year adherence rates in the cohorts were only 40.1% for ACS, 36.1% for chronic CAD, and 25.4% for primary prevention. Relative to the ACS cohort, nonadherence was more likely among patients receiving statins in the chronic CAD (relative risk [RR], 1.14; 95% CI, 1.11–1.16) and primary prevention cohorts (RR, 1.92; 95% CI, 1.87–1.96).

Conclusions

Elderly patients with and without recent ACS have low rates of adherence to statins. This suggests that many patients initiating statin therapy may receive no or limited benefit from statins because of premature discontinuation.