Measuring health-related quality of life in patients treated for substance dependence: differences among instruments and methods of eliciting preferences.

BACKGROUND

Measuring the health-related quality of life is an essential estimation in cost-utility studies. In this research, we provide new evidence about comparing utility scores - in the field of substance dependence. Although the main objective is to compare the EQ-5D-5L and SF-6D with paired gamble, evidence about the SF-6D with standard gamble is also provided.

METHODS

Ninety-four patients with substance dependence were recruited; the SF-6D and the EQ-5D-5L were administered at the beginning of treatment and 6 months thereafter. Differences in treatment effect were estimated by comparing utility gains. All analyses were reproduced for two subgroups of severity.

RESULTS

Both the baseline scores and the treatment effect are sensitive to the instrument used. For severe states, the SF-6D with paired gamble (SF-6D with standard gamble) estimates the lowest (highest) utility. With regard to the impact of treatment, the EQ-5D-5L and SF-6D with paired gamble estimate strongly similar effects for severe states (and both estimate greater effects than does the SF-6D with standard gamble).

CONCLUSIONS

These findings have implications for cost-utility analyses. The incremental cost-utility ratio of treatments intended for severe states is barely sensitive to the choice of EQ-5D-5L or SF-6D with paired gamble.