Measuring and assessing corruption in public health systems in low- and middle-income countries: a scoping review of methods.

Corruption in health systems has serious implications for health outcomes and equitable care. Although various methods exist to measure it, their application, purpose, effectiveness, and context have not yet been systematically consolidated to enable learning. We conducted a scoping review to identify empirical approaches used to measure health-sector corruption globally, with a focus on low- and middle-income countries. We examined the opportunities and challenges of these methods and developed a typology to guide future research. We searched Econlit, Embase, Global Health, Medline, Social Policy and Practice, Web of Science, and websites of international organisations focused on corruption research. Reference lists of included studies were also hand-searched. Two rounds of searches were conducted: first for studies published between 2000 and 2022, then for earlier publications dating back to 1993. Thirty-seven studies were narratively synthesised. Common methods included surveys, interviews, focus groups, and audits. Surveys were more common before 2000. Ethnography, investigative journalism, co-production, and crowdsourcing-though previously recommended-were rarely used or reported in the literature. Often, measuring corruption was not the primary aim, and methods were poorly described. Many lacked a clear definition of corruption or a theoretical grounding. Our review and typology highlight trade-offs between rigour, feasibility, and utility. As demand for evidence in this field grows, consensus on corruption definitions and sub-types is needed to guide study design and improve comparability across contexts. Promising directions include theory-informed mixed methods, context-sensitive designs, qualitative pilots, and interdisciplinary approaches.