Equity Weights for Priority Setting in Healthcare: Severity, Age, or Both?

Background: Priority setting in healthcare can be guided by both efficiency and equity principles. The latter principle is often explicated in terms of disease severity and, for example, defined as absolute or proportional shortfall. These severity operationalizations do not explicitly consider patients' age, even though age may be inextricably related to severity and an equity-relevant characteristic. Objective: This study examines the relative strength of societal preferences for severity and age for informing allocation decisions in healthcare. Methods: We elicited preferences for severity and age in a representative sample of the public in The Netherlands (N = 1025) by applying choice tasks and person-trade-off tasks in a design in which severity levels and ages varied both separately and simultaneously between patient groups. We calculated person trade-off ratios and, in addition, applied ordinary least squares regression models to aid interpretation of the ratios when both severity and age varied. Results: Respondents attached a higher weight (median of ratios: 2.46-3.50) to reimbursing treatment for relatively more severely ill and younger patients when preferences for both were elicited separately. When preferences were elicited simultaneously, respondents attached a higher weight (median of ratios: 1.98 and 2.42) to reimbursing treatment for relatively younger patients, irrespective of patients' severity levels. Ratios varied depending on severity level and age and were generally higher when the difference in severity and age was larger between groups. Conclusions: Our results suggest that severity operationalizations and equity weights based on severity alone may not align with societal preferences. Adjusting decision-making frameworks to reflect age-related societal preferences should be considered.