Association between patient beliefs and medication adherence following hospitalization for acute coronary syndrome

Background: Patient adherence to medications is crucial for reducing risks following acute coronary syndrome (ACS). We assessed the degree to which medication beliefs were associated with patient adherence to β-blockers, angiotensin-converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB), and lipid-lowering medications (LL) 3 months following ACS hospitalization.

Methods: We enrolled eligible ACS patients from 41 hospitals to participate in a telephone survey. The Beliefs in Medication Questionnaire-Specific was administered to assess perceived necessity for and concerns about heart medications. Three cohorts were identified for analysis: β-blockers, ACEI/ARBs, and LL. Patients discharged on or starting the medication class after discharge were included in the cohort. The primary outcome was self-reported nonadherence to the medication class 3 months following hospitalization. Factors associated with nonadherence to each medication class were determined using logistic regression analysis.

Results: Overall, 973 patients were surveyed. Of these, 882 were in the β-blocker cohort, 702 in the ACEI/ARB cohort, and 873 in the LL cohort. Nonadherence rates at 3 months were 23%, 26%, and 23%, respectively. In adjusted analyses, greater perceived necessity for heart medications was significantly associated with lower likelihood of nonadherence in all cohorts (β-blocker: odds ratio 0.94, 95% CI 0.91-0.98; ACEI/ARB: OR 0.94, 95% CI 0.90-0.98; LL: OR 0.96, 95% CI 0.92-1.00). A greater perceived concern was significantly associated with a higher likelihood of nonadherence in all cohorts (β-blocker: OR 1.08, 95% CI 1.04-1.13; ACEI/ARB: OR 1.07, 95% CI 1.02-1.11; LL: OR 1.09, 95% CI 1.05-1.14).

Conclusions: Patients' perceived necessity for and concerns about heart medication were independently associated with adherence to 3 medication classes. Assessment of patient beliefs may be useful in clinical practice to identify those at greatest risk for nonadherence and to stimulate development of individualized interventions to change beliefs and improve adherence.