Eliciting Societal Preferences for Weighting QALYs for Burden of Illness and End of Life

Abstract

Objectives. Recent proposals for value-based assessment, made by the National Institute of Health and Care Excellence (NICE) in the United Kingdom, recommended that burden of illness (BOI) should replace end of life (EOL) as a factor for consideration when deciding on new health technologies. This article reports on a study eliciting societal preferences for 1) BOI from a medical condition, defined as quality-adjusted life year (QALY) loss due to premature mortality and prospective morbidity, and 2) EOL, defined as expected life expectancy of less than 2 years and expected life expectancy gain from new treatment of 3 months or more. Methods. A discrete choice experiment survey was conducted with an online UK general population sample. Respondents chose whether they thought the health service should treat patient group A or B: life expectancy and health-related quality of life (HRQOL) with current treatment or life expectancy and HRQOL gains from new treatment, respectively. These attributes were used to derive BOI, QALY gain, and EOL. The respondents’ choices were analyzed using conditional logistic regression with a range of specifications examined, including BOI or EOL, QALY gain and QALY gain squared, and robustness. QALY weights were estimated. Results. The sample of 3669 respondents was representative of the UK population for age and sex. QALY gain had a positive and significant coefficient across all models. QALY gain squared term was negative and significant across all models, indicating a diminishing marginal social value from QALY gains. When included, the BOI coefficient was generally small, positive, and significant, but this was not consistent across the different life expectancy variants. EOL was always positive and significant. Conclusions. The social value of a QALY gain is not equal between recipients but depends on whether they are end of life, and it may depend on the prospective burden of illness.