Applicability of patient utilities as measures of overall quality of life in rheumatoid arthritis clinical trials

Abstract

Objective. The aim was to determine whether the time trade-off (TTO) and standard gamble utilities can detect treatment-related improvement in overall quality of life in patients with active RA.Methods. We measured TTO and standard gamble utilities in 192 patients before and after escalation of anti-rheumatic treatment in a prospective longitudinal study. We also examined associations between changes in utilities and patient-reported improvement during the study, and with EULAR responses.Results. Mean TTO at baseline was 0.68 (median 0.82) and mean standard gamble 0.80 (median 0.93). Both utilities improved significantly with treatment. Standardized response means, a measure of responsiveness, were 0.37 for the TTO and 0.20 for the standard gamble, and comparable to those of two mental health measures and the CRP, but lower than other RA activity measures. Changes in utilities were not significantly associated with patient-reported improvement. The standard gamble, but not the TTO, had a graded association with EULAR responses. Conclusion.Utilities by the TTO and standard gamble were able to detect improvement in overall quality of life with anti-rheumatic treatment in patients with active RA, suggesting applicability in clinical trials. The standard gamble was associated with reference measures of improvement, although not as strongly as measures of RA activity, as expected with its generic orientation.