Defining informal payments in healthcare: a systematic review

To explore the literature for the definitions of informal payments in healthcare and critically analyze the proposed definitions. This will serve in the process of getting to a coherent definition of informal payments, which will further support acknowledging and addressing them globally.

A search strategy was developed to identify papers addressing informal payments on PubMed, ScienceDirect, Econlit, EconPapers and Google Scholar.

2225 papers were identified after a first search. 61 papers were included in the systematic review. Out of all definitions provided, we selected three definitions as being original. All other definitions either cite these definitions or do not provide new insight into the topic of informal payments. Although informal payments have been nominated by various terms over the years, there is a tendency in recent years towards an agreement to use this singular term. Definitions differ in terms of the relation of informal payments with other informal activities, their legality and the motivation behind them.

The variety of forms which informal payments may take makes it difficult to define them in a comprehensive manner. However, we identified a definition that could serve as a beginning in this process. More effort is needed to build on it and get to a commonly accepted and shared definition of informal payments.