Eliciting Trade-Offs Between Equity and Efficiency: A Methodological Scoping Review

Abstract

Objectives: To identify differences in the approaches and results of studies that elicit equity-efficiency trade-offs that can inform equity-informative cost-effectiveness analysis for healthcare resource allocation.

Methods: We searched Ovid (Medline), EconLit, and Scopus prior to June 25, 2021. Inclusion criteria were: (1) peer-reviewed or (2) gray literature; (3) published in English; (4) survey-based; (5) parameterized a social welfare function to quantify inequality aversion or (6) elicited a trade-off in equity and efficiency characteristics of health interventions. Exclusion criteria were: (1) studies that did not conduct a trade-off or (2) theoretical studies. We abstracted details on study methods, results, and limitations. Studies were grouped by following approach: (1) social welfare function or (2) preference ranking and distributional weighting. We described findings separately for each approach category.

Results: Seventy-seven papers were included, 28 parameterized social welfare functions and 49 were classified as preference ranking and distributional weighting. Study methods were heterogeneous. Studies were conducted across 29 countries. Sample sizes and composition, survey methods and question framing varied. Preferences for equity were mixed. Across both approach categories: 39 studies were classified as clear evidence of inequality aversion; 33 found mixed evidence; and 4 had no evidence of aversion. Evidence of between and within-study heterogeneity was found. Preferences for equity may differ by gender, profession, political ideology, income, and education.

Conclusions: Substantial variability in study methods limit the direct comparability of findings and their use in equity-informed cost-effectiveness analysis. Future researches using representative samples that explore within and between country heterogeneity is needed.

Keywords: distributional cost-effectiveness analysis; distributional weights; equity weighting; equity-efficiency trade-offs; equity-informative cost-effectiveness analysis; inequality aversion; preference ranking; social welfare function.