Background: Statin therapy has been shown to have a positive impact on patients with clinically evident coronary artery disease. Despite the benefit of statin therapy, many patients are nonadherent, with a substantial number being nonadherent by one year. Multiple studies have been performed and interventions have been established to reduce statin nonadherence. Of the various strategies, only multifaceted interventions have been consistently successful. Older studies identified which patients are at risk of poor adherence; however, they did not identify modifiable adherence determinants. Brookhart and associates assessed the effect of physician visits, cholesterol testing, and other encounters with the health care system on statin therapy adherence.

The Study: All adults in one Canadian province who began statin therapy between January 1, 1997, and June 30, 2004, were included in the study. All patient prescriptions were entered into a database that included data such as medication name, dosage, and quantity. Statin nonadherent patients were defined as those who had filled a prescription, but failed to get refills within 90 days. If patients filled their statin prescriptions before their previous prescription should have been completed, they were considered to have continued their statin therapy. In addition, data were collected on physician visits, physician contact, cholesterol testing, and hospitalizations. Analyses were performed on patients who were most likely to reinstate statin therapy after being nonadherent for at least 90 days.

Results: The total study population was 239,911 persons. More than 50 percent of those patients were nonadherent for at least 90 days; of nonadherent patients, 48 percent restarted statin therapy within one year, and 60 percent restarted within two years. Patients who had follow-up visits with the physician who initiated statin therapy were significantly more likely to restart statin therapy (odds ratio [OR], 6.1; 95% confidence interval [CI], 5.9 to 6.3), as were patients who had cholesterol testing (OR, 1.5; 95% CI, 1.4 to 1.5). Patients who had a myocardial infarction or who were hospitalized for other cardiovascular diseases were also more likely to restart statin therapy.

Conclusion: Physicians should understand that patients who are receiving statin therapy may have long periods of nonadherence. Cholesterol testing and follow-up visits with the physician who initiated therapy improved patient adherence. The authors conclude that the results of this study suggest that continuity of care combined with increased follow-up and cholesterol testing could increase long-term adherence.