Table 2.

List of key words for the document search strategy

AND			-OR-	Themes and expressions (grey literature)
-OR-	-OR-	-OR-
User fee*	Aboli*	Developing countr*	Free healthcare	Health services accessibility	Healthcare costs
User charge*	Exempt*	Africa*	Free care	Health facilities	Health insurance
Cost-sharing	Waiv*	Low income countr*	Free service*	Health disparities	Health expenditure*
Cost-recovery	Remov*	Middle income countr*	Free healthcare	Health policy	Health financing
Out-of-pocket	End*	LMIC*	Universal access to healthcare	Health equity	National health programs
	Discontinu*		Universal access to healthcare
	Free

The mandated truncation symbol “*” retrieves records that contain the search term and all possible suffix variations of a root word. For example, “user fee*” will retrieve records containing “fee” and “fees”.