Reporting standards for literature searches and report inclusion criteria: making research syntheses more transparent and easy to replicate.

A complete description of the literature search, including the criteria used for the inclusion of reports after they have been located, used in a research synthesis or meta-analysis is critical if subsequent researchers are to accurately evaluate and reproduce a synthesis' methods and results. Based on previous guidelines and new suggestions, we present a set of focused and detailed standards for reporting the methods used in a literature search. The guidelines cover five search strategies: reference database searches, journal and bibliography searches, searches of the reference lists of reports, citation searches, and direct contact searches. First, we bring together all the unique recommendations made in existing guidelines for research synthesis. Second, we identify gaps in reporting standards for search strategies. Third, we address these gaps by providing new reporting recommendations. Our hope is to facilitate successful evaluation and replication of research synthesis results.