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Grey Literature

Grey Literature in Health Studies

In Health Studies, grey literature Includes conference proceedings; dissertations and theses; government agencies; association websites; ongoing or unpublished clinical trial data; reports and publications. It is produced by all levels of government, academia, NGOs, associations and professional organizations.

For comprehensive searching in the Health Studies, particularly when conducting a systematic review, scoping review or other review syntheses, it is important to search grey literature to:

  • avoid bias
  • supplement your research
  • ensure that the review is as thorough as possible
  • discover current or emergent research
  • find the voices of the population or community group being studied
  • identify programmes, interventions
  • find detailed information on programmes, policies, local initiatives
  • gather statistics as evidence, particularly community-based statistics
  • discover additional references to published literature that your database search might have missed

The sources you select will be informed by your research question. Not all research questions require the use of grey literature.

Finding Grey Literature Sources

Below are some ways in which you can find grey literature resources for health studies:

The following resources can be searched to identify grey literature. 

  • Grey Matters:
    • CADTH's Grey Matters resource is a free online tool for finding health-related grey literature that are not published commercially and which may be inaccessible via bibliographic databases.
  • OpenGrey

Contact known researchers in the field to determine if there are any ongoing or unpublished studies.

Evaluating Grey Literature

Unlike scholarly and peer-reviewed literature, grey literature does not go through a rigorous review process before it is published. For example, some NGOs can be lobby groups for corporations. 

It is important to evaluate grey literature before its inclusion in your research paper or review syntheses.

Documenting Your Search

Document your grey literature search including the resource name; URL; search terms, and date searched.