National patterns and predictors of β-blocker use in patients with coronary artery disease

Background: Prior studies suggest underuse of β-blockers in patients with coronary artery disease, but these studies have been based on selected populations of recently hospitalized patients. Objective: To describe national patterns and determinants of β-blocker use in the ambulatory setting. Methods: We analyzed 11 745 visits by patients with coronary artery disease to randomly selected, office-based physicians in the National Ambulatory Medical Care Surveys for 1980, 1981, 1985, and 1989 through 1996. We used multiple logistic regression to determine the independent effect of sociodemographic and clinical factors on β-blocker use. Outcome Measure: β- Blocker use at patient visits. Results: β-Blocker use was reported in only 20.9% of office visits by patients with coronary artery disease and no strong contraindications between 1993 and 1996. In multivariate analyses, age younger than 75 years, residence in the Northeast, and visits to cardiologists and internists compared with family and general practitioners predicted greater use of β-blocker therapy. White race and private insurance also were significant predictors of β-blocker use between 1980 and 1996. Longitudinal analyses revealed a significant decline in β-blocker use from 1980 to 1990, followed by a gradual increase in recent years. Conclusions: β-Blockers appear to be underused in ambulatory patients with coronary artery disease. Our data suggest that nonclinical factors may influence rates of use, indicating the need for closer scrutiny of variations in physician prescribing practices.