Patient and Practice Factors Associated With Improvement in Use of Guideline-Recommended Therapies for Outpatients With Heart Failure (from the IMPROVE HF Trial)

Abstract

Diverse factors are associated with variations in evidence-based treatment of outpatients with heart failure (HF). However, patient and practice characteristics associated with improved use of guideline-recommended therapies over time have not been well studied. The Registry to Improve the Use of Evidence-Based Heart Failure Therapies in the Outpatient Setting (IMPROVE HF) is a prospective evaluation of a performance improvement initiative conducted at 167 practices treating outpatients with diagnosed HF or previous myocardial infarction and left ventricular ejection fraction ≤35%. Patient characteristics and care practice data were collected by chart abstraction at baseline and 24 months for 14,236 patients. Seven individual care measures and a composite measure were assessed. Practices were stratified by tertiles of composite measure improvement, and significant, independent patient and practice factors associated with improvement in the composite measure at 24 months were examined. The baseline composite performance measure was 68.4%, which increased to 80.1% at 24 months (+11.6%, p <0.001). The composite measure improvement tertiles were ≤8%, >8% to 15%, and >15%. Multivariate analyses revealed greater improvements associated only with lower practice baseline composite measure rates (p <0.001). Logistic regression showed that 2 additional variables were inversely associated with practices in the highest tertile in composite measure improvement (>15%): southern practice location (p = 0.0239) and edema (p = 0.0047). In conclusion, few patient and practice factors were associated with greater or lesser overall improvements over time in the use of guideline-recommended HF therapies. Other factors may be more important determinates of the magnitude of care improvements over time among cardiology practices participating in a performance improvement initiative.