Comparing Short Form 6D, Standard Gamble, and Health Utilities Index Mark 2 and Mark 3 utility scores: Results from total hip arthroplasty patients David Feeny 1,2,3 , Lieling Wu 4 & Ken Eng 1 1 Institute of Health Economics (E-mail: dfeeny@pharmacy.ualberta.ca); 2 Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta; 3 Health Utilities Incorporated, Dundas, Ontario; 4 Department of Medicine, University of Alberta, Edmonton, Alberta, Canada Accepted in revised form 20 December 2003 Abstract Objectives: The objectives are to compare SF-6D, standard gamble (SG), and Health Utilities Index (HUI) utility scores, compare change scores, and compare responsiveness. Methods: A cohort of osteoarthritis patients referred for total hip arthroplasty (THA) were evaluated at the time of referral and followed until 3 months after THA. Patients were assessed using the SF-36, HUI2, HUI3, and the SG. Agreement is assessed using the intra-class correlation (ICC). Responsiveness is assessed using effect size, standardized response mean, and paired t-test. Results: Data was available for 86 patients at baseline and for 63 at both pre- and post-surgery. At baseline mean SF-6D (0.61), SG (0.62), and HUI2 (0.62) scores were similar; the mean HUI3 score (0.52) was lower. Standard deviations were 0.10, 0.32, 0.19, and 0.22. At baseline, agreement between SF-6D and SG scores was 0.13, agreement between SF-6D and HUI2 was 0.47, and agreement between SF-6D and HUI3 was 0.28. Agreement at pre- and post-surgery was similar. The change in scores between post- and pre-surgery was 0.10 for SF-6D, 0.16 for SG, 0.22 for HUI2, and 0.23 for HUI3. Effect sizes were 1.10 for HUI2, 1.08 for HUI3, 1.06 for SF-6D, and 0.48 for the SG. Conclusions: Agreement between SG scores and SF-6D and HUI scores was low. The estimate of change in utility associated with THA was lowest for SF-6D. Additional longitudinal studies to compare utility measures appear to be warranted. Key words: HUI, Responsiveness, SF-6D, Standard Gamble, Utility Scores Introduction The Short-Form 36 Health Survey system (SF-36) is one of the most widely used measures of health status [1–3]. The SF-36 provides eight domain scores and two summary scores, one each for physical and mental health. SF-36 does not, however, generate a single overall summary score. Recently Brazier et al. [4] have provided a means to obtain preference-based single summary scores for health states as assessed using the SF-36 sys- tem. Brazier et al. have estimated a utility function for the SF-6D system which covers a seven of the eight domains included in the SF-36. The scoring function is based on regression results based on a random sample of community preferences scores obtained in the United Kingdom using the stan- dard gamble (SG) approach. How do SF-6D utility scores compare to direct and other multi-attribute utility scores? How does the responsiveness of the SF-6D compare to the other utility scores? This study will compare SF- 6D utility scores to utility scores derived from the Health Utilities Index Mark 2 (HUI2), Health Utilities Index Mark 3 (HUI3), and direct SG scores obtained from patients undergoing elective Quality of Life Research 13: 1659–1670, 2004. Ó 2004 Kluwer Academic Publishers. Printed in the Netherlands. 1659