Outcomes, health policy, and managed care: Relationships between patient-reported outcome measures and clinical measures in outpatients with heart failure

• Published in: The American heart journal 2009-10, Vol.158 (4), p.S64-S71
• Main Authors: Flynn, Kathryn E., PhD, Lin, Li, MS, Ellis, Stephen J., PhD, Russell, Stuart D., MD, Spertus, John A., MD, MPH, Whellan, David J., MD, MHS, Piña, Ileana L., MD, Fine, Lawrence J., MD, DrPH, Schulman, Kevin A., MD, Weinfurt, Kevin P., PhD
• Format: Article
• Language: English
• Subjects: Ambulatory Care - standards; Attitude to Health; Cardiomyopathy; Cardiovascular; Disease; Exercise; Exercise Test - statistics & numerical data; Exercise Tolerance; Female; Fitness equipment; Health Policy; Health Status; Heart failure; Heart Failure - diagnosis; Heart Failure - physiopathology; Heart Failure - therapy; Humans; Male; Managed Care Programs - standards; Medical prognosis; Middle Aged; Mortality; Older people; Outcome Assessment (Health Care) - statistics & numerical data; Oxygen Consumption - physiology; Patients; Physical fitness; Prognosis; Quality of Life; Surveys and Questionnaires; Ventricular Dysfunction, Left - diagnosis; Ventricular Dysfunction, Left - physiopathology; Ventricular Dysfunction, Left - therapy
• ISSN: 0002-8703; 1097-6744
• DOI: 10.1016/j.ahj.2009.07.010

Background Patient-reported outcomes are increasingly used to assess the efficacy of new treatments. Understanding relationships between these and clinical measures can facilitate their interpretation. We examined associations between patient-reported measures of health-related quality of life and clinical indicators of disease severity in a large, heterogeneous sample of patients with heart failure. Methods Patient-reported measures, including the Kansas City Cardiomyopathy Questionnaire (KCCQ) and the EuroQol Visual Analog Scale (VAS), and clinical measures, including peak V o2 , 6-minute walk distance, and New York Heart Association (NYHA) class, were assessed at baseline in 2331 patients with heart failure. We used general linear models to regress patient-reported measures on each clinical measure. Final models included for significant sociodemographic variables and 2-way interactions. Results The KCCQ was correlated with peak V o2 ( r = .21) and 6-minute walk distance ( r = .27). The VAS was correlated with peak V o2 ( r = .09) and 6-minute walk distance ( r = .11). Using the KCCQ as the response variable, a 1-SD difference in peak V o2 (4.7 mL/kg/min) was associated with a 2.86-point difference in the VAS (95% CI, 1.98-3.74) and a 4.75-point difference in the KCCQ (95% CI, 3.78-5.72). A 1-SD difference in 6-minute walk distance (105 m) was associated with a 2.78-point difference in the VAS (95% CI, 1.92-3.64) and a 5.92-point difference in the KCCQ (95% CI, 4.98-6.87); NYHA class III was associated with an 8.26-point lower VAS (95% CI, 6.59-9.93) and a 12.73-point lower KCCQ (95% CI, 10.92-14.53) than NYHA class II. Conclusions These data may inform deliberations about how to best measure benefits of heart failure interventions, and they generally support the practice of considering a 5-point difference on the KCCQ and a 3-point difference on the VAS to be clinically meaningful.