The relationship between health perception and utility in heart failure patients in a clinical trial: results from an OVERTURE substudy

Abstract

Background Cost-effectiveness analyses should be based on incremental years of life gained adjusted with a health status measure known as a utility. Measuring utilities for all subjects in a large-scale randomized trial, however, would be prohibitively cumbersome. We therefore sought to estimate utilities for all subjects from results obtained in a subset of patients. Methods and results We studied a subset of patients enrolled in a randomized trial of omapatrilat for the treatment of heart failure. Survey instruments (a time trade-off questionnaire, a visual analog scale [VAS] score of overall health perception, and the Duke Activity Status Index [DASI]) were administered to patients by mail and by telephone interviews. There was a significant ( P < .0001) relationship between VAS score and utility described by the power function u = 1–(1–v)q, where q = 2.17 (95% CI 1.76 to 2.58). There was a significant positive correlation (r = .17, P < .04) between the DASI and utility, and a significant negative correlation (r = –.26, P < .001) between utility and New York Heart Association functional class. Conclusion There is a significant relationship between the relatively easily obtainable health perception score by VAS with the more complex utility by time tradeoff for a subset of patients in a multicenter randomized clinical trial. This relationship may be helpful in examining the cost-effectiveness of new treatments for heart failure.