Methodological heterogeneity and equity challenges of distributional cost-effectiveness analysis in healthcare: a systematic review from 2017 to 2025.

backgroundHealth equity has become a key focus of global health policy. Distributional cost-effectiveness analysis (DCEA) is one of the most commonly used methods for incorporating health equity into health economics evaluations. However, systematic reviews specifically on DCEA in healthcare remain scarce, and its research methods, findings, and quality have not been clearly summarized.

methodsA systematic review was conducted in accordance with PRISMA 2020 guidelines, drawing from PubMed (MEDLINE), Web of Science, the Cochrane Library, CNKI, Wanfang, and VIP from inception to 30th August 2025. We included empirical studies in healthcare field that explored the costs and health outcomes of at least two healthcare interventions through DCEA. A total of 923 articles were identified, of which 28 studies met the eligibility criteria. The Quality of Health Economic Studies (QHES) and Consolidated Health Economic Evaluation Reporting Standards (CHEERS) 2022 were both used to assess the quality of the literature. An inductive content analysis was employed to extract detailed research characteristics, identify methodological and outcome differences in DCEA.

resultsAll studies were of high quality based on QHES. Relevant research was highly concentrated in developed regions (75.00%), primarily North America and Europe. Infectious diseases (28.57%) and cancers (21.43%) were the most common disease domains. Markov models (25.00%) and Micro-simulation models (21.43%) were the most widely used. Subgroup division mainly relied on societal and structural variables (46.43%) and race and ethnicity (32.14%) as the core basis for equity analysis. The Atkinson index was the most common equity indexes. 85.71% reported win-win interventions, while only one yielded a lose‑lose outcome; a further six studies identified trade‑offs between equity and efficiency.

conclusionWe elaborated on three key methodological distinctions in DCEA: the basis for subgroup classification, modeling methodology and equity indexes. We identified the following challenges in conducting DCEA: a lack of certified equity subgroup classification criteria and measurement frameworks; difficulties in obtaining evidence for key equity parameters; and policymakers’ unfamiliarity with the method and insufficient emphasis on prioritizing equity considerations.

trial registrationThe protocol and search strategy were registered and published in the PROSPERO International Prospective Register of Systematic Reviews (CRD420251169448).