Predicting patients' utilities from quality of life items: an improved scoring system for the UBQ-H

The Utility-based Quality of Life - Heart Questionnaire (UBQ-H) is a cardio vascular extension of the Health Measurement Questionnaire. It is a multidi mensional instrument that can be scored to yield a utility estimate using t he Rosser Index and a classification algorithm developed for the Health Mea surement Questionnaire. The aim of this study was to employ a statistical m odelling approach to devise an improved scoring system. A sample of 201 car diovascular patients completed the UBQ-H and assessed the utility of their own health state using standard gamble and time trade-off questions in an i nterview. Two new scoring methods were devised by regressing the UBQ-H data against patients' self-assessed utilities. The new methods gave utility es timates that correlated with angina/dyspnoea grades, life satisfaction scor es and General Health Questionnaire (GHQ) scores. In a second sample of 1,1 12 cardiovascular patients, the UBQ-H utilities were able to distinguish be tween patients who had/had not experienced an adverse event (e.g. myocardia l infarction) and were responsive to changes in health over time. The new s coring methods were not particularly more sensitive to quality of life effe cts than the original method based on the Rosser Index. However, they produ ced significantly lower estimates and more accurately reflected patients' s elf-assessed utilities.