Objective: The time trade-off is a health-related quality of life instrument that measures valuations for health states (utilities) by asking patients to value their health state anchored on a scale between death (0) and perfect health (1). Dying earlier is not perceived as a realistic worst-case consequence of the disease by RA patients. Of the previous focus groups study on RA patients, five worst-case future scenarios emerged. The aim of this study was to examine which potential worst-case scenario was the most appropriate for RA patients to use in utility calculation.
Methods: In a cross-sectional study of 74 consecutive RA patients visiting the rheumatology outpatient clinic, participants were presented with descriptions of the five worst-case future scenarios. In pairwise comparisons, patients had to choose the scenario that would be the worst to experience. The worst-case future scenario was defined by the scenario that was chosen by a significantly greater proportion of participants than could be expected based on chance (20%). Therefore, analysis based on a single fraction ( ) was used and 95% CI was calculated.
Results: The scenario being dependent on others was chosen most often as the worst to experience [by 35% of participants (95% CI 24%, 46%)] and significantly more often than could be expected based on chance ( = 0.35, z = 6.45, P = 0.00).
Conclusion: The scenario being dependent on others is likely to be the most appropriate worst-case future scenario for RA patients. Using an alternative anchor could improve the validity and responsiveness of the time trade-off in RA patients.