Relating quality of care to clinical outcomes in heart failure: In search of the missing link

Abstract

As heart failure becomes an increasingly important public health problem in the aging population, all avenues continue to be sought toward improving clinical outcomes among patients with this condition. From the perspective of clinical care, this process most appropriately begins with the demonstration of a significant treatment effect within a randomized clinical trial. Drawing upon such information, uniform guidance must be provided to the practitioner, defining a consensus view of optimal quality of care. Such guidance, in the form of clinical practice guidelines, has reached beyond the realm of randomized clinical trial evidence, drawing from multiple sources of information, often with weak or absent documentation of linkage between the clinical process being advocated and the outcome being sought. Polanczyk et al (1) in this issue of the Journal of Cardiac Failure provide some of this linkage by examining correlation between indices of quality of care for patients hospitalized with heart failure and the important clinical outcome of hospital readmission. Krumholz et al (2) recently reviewed quality measures in heart failure. They reported characteristics of guideline recommendations that are most appropriately translated into measures to judge the quality of care delivery, including 1) strong process-outcome linkage, 2) wide applicability to a well-defined patient population, and 3) amenability to measurement based on existing or readily adapted documentation standards. At present, few recommendations meet these rigorous requirements. The Centers for Medicare and Medicaid Services (previously the Health Care Finance Administration) in an effort to improve quality of care in heart failure have adapted 2 measures that come close to meeting these standards: measurement of left ventricular function and prescription of angiotensin-converting enzyme (ACE) inhibitors. In contrast, Polanczyk et al explored an instrument based on a wide variety of quality measures for inhospital management, including criteria for 1) admission work-up, 2) evaluation and treatment during hospitalization, and 3) readiness for discharge. They correlated scores on the various components of this instrument with the likelihood of rehospitalization for heart failure during 3 months of follow-up in 200 patients discharged alive after index hospitalization for heart failure. Using a multivariate model that included both clinical characteristics and quality criteria, the investigators observed that a low score for evaluation and treatment independently predicted readmission. Patients meeting 50% of the evaluation and treatment criteria were 2.5 times more likely to be readmitted for heart failure than the remaining population. The frequency of 1) performing any diagnostic evaluation, 2) performing echocardiography in patients with an unknown ejection fraction, and 3) treatment with an ACE inhibitor differed significantly between patient groups with and without readmission. Although the precise mechanism for linkage between the diagnostic evaluation, including echocardiography, and readmission is uncertain, these findings bring us a step closer to documenting that improvement in clinical practice, based on established quality standards, yields improved clinical outcomes in patients with heart failure. Readmission after a hospitalization for heart failure is common, estimated as 44% at 6 months within the Medicare population (3). Reduction in heart failure hospitalizations is an appropriate goal for treatment modalities and quality improvement strategies because hospitalization impacts adversely on both sides of the cost-effectiveness equation. On the cost side, hospitalization is the principal component of the high cost of care for patients with heart failure, representing 70% to 75% From the Division of Cardiology, Department of Medicine, New England Medical Center and Tufts University School of Medicine, Boston, MA. Reprint requests: Marvin A. Konstam, MD, Hospital Box 108, New England Medical Center, 750 Washington St, Boston, MA 02111. Copyright © 2001 by Churchill Livingstone 1071-9164/01/0704-0004$35.00/0 doi:10.1054/jcaf.2001.30132 Journal of Cardiac Failure Vol. 7 No. 4 2001