Skip Navigation Archive: U.S. Department of Health and Human Services U.S. Department of Health and Human Services
Archive: Agency for Healthcare Research Quality
Archival print banner

This information is for reference purposes only. It was current when produced and may now be outdated. Archive material is no longer maintained, and some links may not work. Persons with disabilities having difficulty accessing this information should contact us at: Let us know the nature of the problem, the Web address of what you want, and your contact information.

Please go to for current information.

Searching the Grey Literature: Where To Look and What To Expect (Text Version)

Slide Presentation from the AHRQ 2011 Annual Conference

On September 20, 2011, Rose Relevo made this presentation at the 2011 Annual Conference. Select to access the PowerPoint® presentation (80 KB). Plugin Software Help.

Slide 1

Searching the Grey Literature: Where to Look and What to Expect

Rose Relevo, MLIS, MS
Oregon Health & Sciences University
Effective Healthcare Program Scientific Resource Center

Slide 2

Image: The graphic is of a Venn diagram describing various sources and types of grey literature. The largest circle represents all grey literature. There is a smaller circle representing the subset that is called data from clinical trials, indicating that data from clinical trials represents only a small part of the larger universe of grey literature. There are four additional circles intersecting with this, representing four types of publications that may contain clinical data. The overlap shows that only some of these publications present clinical data. The fours sources represented are: Regulatory Documentation, Conference Papers, Trial Registries and Other. The larger point of this diagram is to illustrate that grey literature is a term that refers to a large and diverse set of resources. For the purposes of completing systematic reviews and comparative effectiveness reviews, we are really only concerned with data from clinical trials which is most likely to be found via clinical trial registries, regulatory documentation and conference materials.

Slide 3

Trial Registries

  • metaRegister of Controlled Trials (mRCT):
      • ISRCTN Register (International).
      • National Institutes of Health (NIH)
      • Action Medical Research (UK).
      • The Wellcome Trust (UK).
      • Medical Research Council (UK).
      • UK trials (UK).

Slide 4

Trial Registries

    • PhRMA database.
  • World Health Organization (WHO) International Clinical Trials Registry Platform Search Portal:
    • Australia, New Zealand, US, UK, Brazil, China, India, Korea, Cuba, Germany, Iran, Japan, Pan African, Sri Lanka, The Netherlands.

Slide 5

What Do You Get From a Trial Registry

  • Know that a study exists:
    • Identify forthcoming publications.
    • Window into publication bias.
    • Future research needs.
  • Results.
  • Protocols.
  • Contact information.

Slide 6


  • "Small" databases, searches can be simple.
  • EndNote® import filter for results.

Slide 7

Regulatory Documentation

Slide 8

Regulatory Documentation

Slide 9


  • Food and Drug Administration (FDA) database not optimized for our purposes.
  • "Searching" not quite accurate, "directed browsing" more accurate.
  • Delegate to well trained personnel.
  • Podcasts; biggest danger is spacing out.

Slide 10


  • Conference paper databases:
    • CSA Conference Papers Index.
    • Scopus.
    • BIOSIS Previews.
    • Papers and Proceedings First.
  • Specific conferences (key informants, technical experts).

Slide 11


  • Access will vary by institution.
  • Simple searches usually sufficient.
  • Identify upcoming publications.
  • Compare to published versions.
  • Contact authors for more information.

Slide 12

Other Sources

Slide 13

For More...

Secure site:
Resources/Grey Literature Materials

Page last reviewed October 2014
Internet Citation: Searching the Grey Literature: Where To Look and What To Expect (Text Version): Slide Presentation from the AHRQ 2011 Annual Conference. October 2014. Agency for Healthcare Research and Quality, Rockville, MD.


The information on this page is archived and provided for reference purposes only.


AHRQ Advancing Excellence in Health Care