Gray literature

An important resource in systematic reviews

Dados Bibliográficos

ID23348136
AutoresArsenio Paez (Nuffield Department of Primary Care Health Sciences, Department for Continuing Education The University of Oxford Oxford UK)
Ano2017
Volume10
Fascículo3
Páginas233-240
Data de publicação2017-08-01
Peer ReviewedSim
Open AccessSim
TipoARTICLE
PeriódicoJournal of Evidence-Based Medicine (JOURNAL)
Identificadores do periódicoISSN: 1756-5383 • E-ISSN: 1756-5391
EditoraWiley (PUBLISHER • GB)
DOI10.1111/jebm.12266
IdiomaEN
Citações recebidas199
Referências citadas32

Systematic reviews aide the analysis and dissemination of evidence, using rigorous and transparent methods to generate empirically attained answers to focused research questions. Identifying all evidence relevant to the research questions is an essential component, and challenge, of systematic reviews. Gray literature, or evidence not published in commercial publications, can make important contributions to a systematic review. Gray literature can include academic papers, including theses and dissertations, research and committee reports, government reports, conference papers, and ongoing research, among others. It may provide data not found within commercially published literature, providing an important forum for disseminating studies with null or negative results that might not otherwise be disseminated. Gray literature may thusly reduce publication bias, increase reviews’ comprehensiveness and timeliness, and foster a balanced picture of available evidence. Gray literature's diverse formats and audiences can present a significant challenge in a systematic search for evidence. However, the benefits of including gray literature may far outweigh the cost in time and resource needed to search for it, and it is important for it to be included in a systematic review or review of evidence. A carefully thought out gray literature search strategy may be an invaluable component of a systematic review. This narrative review provides guidance about the benefits of including gray literature in a systematic review, and sources for searching through gray literature. An illustrative example of a search for evidence within gray literature sources is presented to highlight the potential contributions of such a search to a systematic review. Benefits and challenges of gray literature search methods are discussed, and recommendations made.