Utility Assessment in Cancer Patients

Abstract

The standard gamble (SG) and the time tradeoff (TTO), two frequently used methods of utility assessment, have often been found to lead to different utilities for the same health state. The authors investigated whether adjustment of TTO scores for the utility of life years (risk attitude) eliminated this difference. In addition, the association between risk attitude and sociodemographic and medical variables was studied. In 30 disease-free testicular cancer patients, SG and TTO were used to assess the utilities of four health profiles relevant to testicular cancer. Utility of life years was estimated from certainty equivalents (CEs). SG scores were significantly higher than unadjusted TTO scores for all profiles. As the majority of patients (85%) were risk-averse, CE-adjusted TTO scores were higher than unadjusted scores, and were not significantly different from those obtained from the SG for three of the four profiles. However, adjusted scores were still slightly but consistently lower than SG scores. Possible explanations for this discrepancy are discussed. An association was found between risk aversion and medical treatment: patients who had received chemotherapy for their cancers were more risk-averse than were patients who had been in a surveillance protocol only. As risk aversion can have an impact on treatment decisions, it is important to assess the risk posture of the patient to whom the decision pertains. Key words: utility assessment; QALY; risk aversion; oncology; treatment preferences. (Med Decis Making 1994;14:82-90)