Practice-Level Variation in Use of Recommended Medications Among Outpatients With Heart Failure

Abstract

Background— The objective of this study is to examine practice-level variation in rates of guideline-recommended treatment for outpatients with heart failure and reduced ejection fraction, and to examine the association between treatment variation and practice site, independent of patient factors. Methods and Results— Cardiology practices participating in the National Cardiovascular Disease Registry Practice Innovation and Clinical Excellence registry from July 2008 to December 2010 were evaluated. Practice rates of treatment with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and β-blockers and an optimal combined treatment measure were determined for patients with heart failure and reduced ejection fraction and no documented contraindications. Multivariable hierarchical regression models were adjusted for demographics, insurance status, and comorbidities. A median rate ratio was calculated for each therapy, which describes the likelihood that the treatment of a patient with given comorbidities would differ at 2 randomly selected practices. We identified 12 556 patients from 45 practices. The unadjusted practice-level prescription rates ranged from 44% to 100% for angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (median, 85%; interquartile range, 75%–89%), from 49% to 100% for β-blockers (median, 92%; interquartile range, 83%–95%), and from 37% to 100% for optimal combined treatment (median, 79%; interquartile range, 66%–85%). The adjusted median rate ratio was 1.11 (95% confidence interval, 1.08–1.18) for angiotensin-converting enzyme inhibitors/angiotensin receptor blockers therapy, 1.08 (95% confidence interval, 1.05–1.15) for β-blockers therapy, and 1.17 (1.13–1.26) for optimal combined treatment. Conclusions— Variation in the use of guideline-recommended medications for patients with heart failure and reduced ejection fraction exists in the outpatient setting. Addressing practice-level differences may be an important component of improving quality of care for patients with heart failure and reduced ejection fraction.