Use of statins and beta-blockers after acute myocardial infarction according to income and education

Objective: To study the initiation of and long-term refill persistency with statins and beta-blockers after acute myocardial infarction (AMI) according to income and education. Design and setting: Linkage of individuals through national registers of hospitalisations, drug dispensation, income and education. Participants: 30 078 patients aged 30-74 years surviving first hospitalisation for AMI in Denmark between 1995 and 2001. Main outcome measures: Initiation of statin or beta-blocker treatment (out- patient claim of prescriptions within 6 months of discharge) and refill persistency (first break in treatment lasting at least 90 days, and reinitiation of treatment after a break). Results: When simultaneously estimating the effect of income and education on initiation of treatment, the effect of education attenuated and a clear income gradient remained for both drugs. Among patients aged 30-64 years, high income (adjusted hazard ratio (HR) 1.27; 95% confidence interval (CI) 1.19-1.35) and medium income (HR 1.13; 95% CI 1.06-1.20) was associated with initiation of statin treatment compared with low income. The risk of break in statin treatment was lower for patients with high ( HR 0.73; 95% CI 0.66-0.82) and medium (HR 0.82; 95% CI 0.74-0.92) income compared with low income, whereas there was a trend in the opposite direction concerning a break in beta-blocker treatment. There was no gradient in reinitiation of treatment. Conclusion: Patients with low compared with high income less frequently initiated preventive treatment post-AMI, had worse long-term persistency with statins, but tended to have better persistency with beta-blockers. Low income by itself seems not to be associated with poor long-term refill persistency post-AMI.