Searching grey literature: Grey Matters

A Summary of

Canadian Agency for Drugs and Technologies in Health (2011). Grey Matters: A Practical Search Tool for Evidence-Based Medicine. Ottawa: ON.


Developed by the Canadian Agency for Drugs and Technologies in Health (CADTH), Grey Matters: A Practical Search Tool for Evidence-based Medicine is a checklist to use when searching grey literature reports that are not accessible through bibliographic databases. Grey Matters is a comprehensive list of Canadian and international government health technology assessment (HTA) websites, health economics resources and health prevalence or incidence databases.

Created by the Information Services team at CADTH, this checklist serves to:

  • ensure retrieval of relevant government, evidence-based agency reports that may not be indexed in bibliographic databases;
  • document the grey literature search process so that is transparent and reproducible; and
  • ensure a standard and systematic approach to searching grey literature.

Grey Matters includes Canadian and international websites with tips on searching websites and Internet searching.

Access the Tool

Format of the Tool


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Using the Tool

Time for Participation/Completion

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Additional Resources and/or Skills Needed for Implementation


Steps for Using Method/Tool

The Grey Matters checklist is organized by topic, with drop-down boxes to document success when retrieving grey literature reports. Topics include:

  • health technology assessment agencies
  • health economics
  • clinical practice guidelines
  • drug and device regulatory approvals
  • advisories and warnings
  • drug class reviews
  • clinical trials
  • Canadian drug formularies
  • databases (free)
  • statistics
  • miscellaneous (Internet searching, open access journals, ethics)

Who is involved

Librarians, project specialists and others involved in searching for information as part of an evidence review or rapid review process would benefit from using this tool.

Conditions for Use

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Evaluation of the Tool


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Methodological Rating

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Development of the Tool


Canadian Agency for Drugs and Technologies in Health

Method of Development

Information Specialists at CADTH developed Grey Matters to support the increasing relevance of grey literature in evidence-informed decision making.

Release Date


Contact Person/Source

Hayley Fitzsimmons
Canadian Agency for Drugs and Technologies in Health
600-865 Carling Avenue
Ottawa, ON K1S 5S8
Phone: (613) 226-2553

These summaries are written by the NCCMT to condense and to provide an overview of the resources listed in the Registry of Methods and Tools and to give suggestions for their use in a public health context. For more information on individual methods and tools included in the review, please consult the authors/developers of the original resources.

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