Knowledge Guides: Systematic Reviews: Grey Literature

Why Search Grey Literature?

Impacts publication bias
Can alleviate the effect size of study interventions
Enhances the level of evidence

Search Methods

Hand Search of journals in the field - which journals are important in this field?
Citation Search - which papers have cited this article?
Bibliographies of Articles - what other papers does this author cite?
Pertinent Authors - who is important in this field?

Resources for Grey Literature

Grey Literature Report from NY Academy of Medicine
The report is a bimonthly publication of The New York Academy of Medicine alerting readers to new grey literature publications in health services research and selected urban health topics. Grey Literature resources are cataloged and indexed using MeSH. The database allows full text keyword searching as well as subject searching and serves as an archive for the Reports.
GreyNet International
Founded in 1992, the goal of GreyNet is to facilitate dialog, research, and communication between persons and organizations in the field of grey literature. GreyNet seeks to identify and distribute information on and about grey literature in networked environments.
Kaiser Family Foundation
Kaiser is a non-profit organization focusing on national health issues, as well as the U.S. role in global health policy. Kaiser develops and runs its own policy analysis, journalism and communications programs, sometimes in partnership with major news organizations.
LILACS Literatura Latino Americana em Ciencias de Saude
An important and comprehensive index of scientific and technical literature of Latin America and the Caribbean. For 30 years contributing to increase visibility, access and quality of health information in the Region.
OAlster
A union catalog of millions of records representing open access resources that was built by harvesting from open access collections worldwide. OAIster includes more than 25 million records representing digital resources from more that 1,100 contributors.
Open Grey - Literature in Europe
System for Information on Grey Literature in Europe is your open access to 700.000 bibliographical references of grey literature produced in Europe. Examples of grey literature include technical or research reports, doctoral dissertations, some conference papers, some official publications
Science.Gov
Gateway to U.S. Federal Science. Search over 60 databases and over 2,200 selected websites from 15 federal agencies, for research and development results. Topics include health and science, agriculture, environment, informatics, and more.
TRIP
Incorporates various types of information, such as practice guidelines, systematic reviews, study abstracts and other sources from around the world in this evidence based practice database.
WHOLIS
World Health Organization's online catalog from 1948 to current.
Primary Health Care Research & Information Service (PHCRIS)
Gives a short description of Grey Literature and links to many GL databases both general and specialized on primary health care.

Evaluate Grey Literature

Evaluating grey literature can be difficult because many of the standard indicators of quality, such as the reputation of the author, can be missing.

The AACODS Checklist is a well known and widely accepted instrument that you can use to assess what you find. It is made up of the following 6 elements:

Authority: Is the author credible?
Accuracy: Is it supported by documented and authoritative references? Is there a clearly stated methodology? Is it 'in line' with other work on the same topic?
Coverage: Have limitations been imposed and are these stated clearly?
Objectivity: Can bias be detected?
Date: Can't find the date? Avoid materials without dates
Significance: Is it relevant? Would it enrich or have an impact on your research?

AACODS Checklist

This material is quoted from "Grey/Gray Literature: What is Grey Literature?" a guide composed by Kathleen Carlson.