To motivate the role for preference assessment in women’s health and to report pilot data addressing the performance of automated time-trade-off (TTO) valuations of current health, which were developed to estimate quality-adjusted life years (QALYs) in the women’s health setting.
Values for current health relative to perfect health and death were assessed using an annual time trade-off (1-year horizon and sleep as the trading metaphor), a lifetime time trade-off, and a visual analog scale (VAS). All instruments were administered twice within a 12- to 14-day window among a convenience sample of 27 women.
Valuation of health was similar for both time trade-offs (mean of 0.95 for both), but was significantly lower for the VAS (mean of 0.84, Wilcoxon signed-rank p-value < 0.001). Reliability using the intraclass correlation coefficient was 0.67 ± 0.09 and 0.75 ± 0.07 for the annual and lifetime time trade-offs, respectively, and 0.89 ± 0.03 for the VAS. Construct validity was supported by consistent trends in time-trade-off utilities across tertiles of the Short Form 36 (SF-36) general health subscale (trend test p-value < 0.001).
Automated time trade-offs for current health provide a promising approach for use in women’s health studies where impact on QALYs must be measured. Natural areas of application include the economic evaluation of preventive interventions in postmenopausal women.