A time tradeoff method for eliciting partner's quality of life due to patient's health states in prostate cancer.

Background: Cost-effectiveness analyses may better reflect the full costs and benefits of medical interventions if they incorporate the effects of patients' health on their family members.

Objective: To develop and apply a time tradeoff (TTO) technique to measure the impact of potential prostate cancer-related health states of the patients on the quality of life (QOL) of their partners.

Methods: We developed modified TTO questions and applied them in a pilot study in which we asked the partner of the patient to tradeoff his or her own life in order to reduce the burden that he himself or she herself expects to experience if the patient developed one of the prostate cancer-related health states. We reviewed the theoretical justification for this question and carefully framed the question so as to reduce measurement error and also to avoid possible double counting with the effect on the partner's health.

Results: We collected data from 26 partners about their preferences for their own health, which is influenced by the patient's health condition. The mean QOL weights for the partners when the patients are the following states are healthy, 0.81; impotent, 0.66; incontinent, 0.68; have metastatic disease, 0.50; and dead, 0.28. Partners' responses varied by how close they felt to the patients. Low correlations between partners' and patients' QOL ratings (n = 15) suggest that the partners were not responding as proxies for the patient.

Conclusions: A new TTO method is proposed to measure a partner's QOL due to a patient's health. Preliminary test results of validity were promising.