DO PATIENTS EVALUATIONS OF A FUTURE HEALTH STATE CHANGE WHEN THEY ACTUALLY ENTER THAT STATE

Fundamental to using utilities for future health states for clinical d ecision analysis is the assumption that the utilities are stable. The purpose of this study was to determine if cancer patients' prior evalu ations of a treatment-induced health state remain stable when they lat er experience that state. Before a four-week course of radiation thera py, 66 laryngeal cancer patients evaluated three common treatment-indu ced outcome scenarios (mild/moderate/severe) using rating scales and t he time trade-off, and provided self-assessments of voice symptoms, vo ice function, and general health. Evaluations and self-assessments wer e repeated at the end of therapy, and respondents indicated which outc ome scenario described their actual end-of-therapy state. Twenty-four patients identified the mild scenario as their outcome state, 36 the m oderate, and 6 the severe. No across-time differences in evaluations w ere detected, although significant (P <.0001) downward shifts in score s for voice symptoms (t = 5.67), voice function (t = 5.10), and genera l health (t = 6.69) indicated that actual change in health status had occurred. These results imply that patients' evaluations of imagined s hort-term health states encountered during radiation therapy for laryn geal cancer remain consistent when those states are experienced at a l ater time. The design of this project provides a model for determining if this consistency appears in other clinical situations.