Equity of financial protection for health care in high-income countries: A systematic scoping review

BACKGROUND: Financial protection is a central objective of health systems and a key mechanism for advancing health equity within universal health coverage. To date, evidence on the equity of financial protection in high-income countries has not been systematically synthesized. OBJECTIVE: To summarize the literature on the equity of financial protection for health care in high-income countries. METHODS: We conducted a systematic scoping review based on a published protocol. We searched four academic (Embase, MEDLINE, IBSS, EconLit) and three grey literature (WHO, OECD, World Bank) databases for data addressing four domains: (i) variables used to characterize equity, (ii) financial protection indicators, (iii) observed financial protection distributions, and (iv) conceptualizations of equity. Eligible records were original research published in any language since 2010. Two reviewers independently assessed records for eligibility. Findings were synthesized narratively. RESULTS: Seventy-five records were included from 4142 screened results, covering data from 48 countries. The largest number of studies focused on the Republic of Korea (n = 13) and the United States (n = 11). Inequalities of financial protection were observed for at least one determinant of health in each setting, across diverse indicators and individual or group stratifiers. Most studies insufficiently conceptualized equity, limiting assessment of outcomes as equitable or inequitable. Notable gaps include the underrepresentation of important variables (e.g. migration status, area-level deprivation, and social class), minimal examination of disproportionate advantage, and the inconsistent application of more equity-sensitive analytical methods. CONCLUSION: This review provides the first systematic synthesis of evidence on the equity of health system financial protection in high-income countries. Key issues that warrant attention in future research and practice include clearer conceptualization of equity and the analysis of underrepresented determinants of health and disproportionate advantage.