The hidden financial burden of healthcare: a systematic literature review of informal payments in Sub-Saharan Africa [version 1; peer review: 1 approved, 2 approved with reservations]
Background: Informal payments limit equitable access to healthcare.Despite being a common phenomenon, there is a need for an in-depth analysis of informal charging practices in the Sub-Saharan Africa (SSA) context.We conducted a systematic literature review to synthesize existing evidence on the prevalence, characteristics, associated factors, and