Paper Standard Gamble Is a Useful Utility and Patient Reported Outcome Measure in Crohnʼs Disease

Abstract

Introduction: There is increasing emphasis on patient reported outcomes and quality of life (QOL) measures in assessment of patients with Crohn's disease (CD). Descriptive QOL measures often require time-consuming questionnaires comprised of multiple QOL domains. Utility assessment is an attractive alternative measure because it provides a single global measure of overall QOL. The paper standard gamble (PSG) is a 1-page questionnaire in which patients are offered a hypothetical pill that confers a specific risk of either perfect health or death and has been shown to be a simple and reliable measure of patient utility. In this study we compared patients in different CD health states with respect to their generic health measure (EQ5D), health rating (EQ5D visual analog scale (VAS)), and utility (PSG). Methods: We prospectively surveyed adults with CD seen for outpatient gastroenterology clinic evaluation. Patients provided informed consent and filled out both the EQ5D and PSG. A gastroenterologist blinded to questionnaire results reviewed the clinic visit and classified the patient's health state based on symptoms (symptomatic or asymptomatic) and objective assessment (active disease, inactive disease, or no testing if none had been done within 6 months of the clinic visit). Results: 219 CD patients (mean age 41.9 years; range 18-77) were recruited. Disease duration was 16.5 + 12.9 years and 57% had prior CD abdominal surgery. The EQ5D index score, EQ5D VAS and the PSG all differentiated between asymptomatic and symptomatic patients but did not differentiate between inactive and active disease states (Tables 1 and 2). When comparing the most extreme of the four health states, asymptomatic inactive (“remission”) versus the symptomatic active groups, all 3 scales differentiated between states (Table 3). The Spearman rank correlation between the utility and other measures was weak. Conclusion: While symptomatic patients had lower health ratings and generic health measures, their utilities were not significantly different from asymptomatic patients. Disease activity was not associated with changes in any measure. Symptomatic patients with objective active inflammation appear willing to take a 7.3% greater risk of death in exchange for perfect health compared to patients with no symptoms and no active disease. Given the limited correlation between utility and other measures, the PSG, a simple one question utility, can be an important tool for clinical trials and QOL studies.689_A Figure 1. Correlation of symptoms and disease activity with EQ5D and PSG689_B Figure 2. Comparison of asymptomatic inactive patients to symptomatic active patients