Grey Literature Searching for Health Sciences Systematic Reviews: A Prospective Study of Time Spent and Resources Utilized


  • Ahlam A. Saleh University of Arizona
  • Melissa A. Ratajeski University of Pittsburgh
  • Marnie Bertolet University of Pittsburgh



systematic reviews, literature search, grey literature, time, health sciences



Objective – To identify estimates of time taken to search grey literature in support of health sciences systematic reviews and to identify searcher or systematic review characteristics that may impact resource selection or time spent searching.

Methods – A survey was electronically distributed to searchers embarking on a new systematic review. Characteristics of the searcher and systematic review were collected along with time spent searching and what resources were searched. Time and resources were tabulated and resources were categorized as grey or non-grey. Data was analyzed using Kruskal-Wallis tests.

Results – Out of 81 original respondents, 21% followed through with completion of the surveys in their entirety. The median time spent searching all resources was 471 minutes, and of those a median of 85 minutes were spent searching grey literature. The median number of resources used in a systematic review search was four and the median number of grey literature sources searched was two. The amount of time spent searching was influenced by whether the systematic review was grant funded. Additionally, the number of resources searched was impacted by institution type and whether systematic review training was received.

Conclusions – This study characterized the amount of time for conducting systematic review searches including searching the grey literature, in addition to the number and types of resources used. This may aid searchers in planning their time, along with providing benchmark information for future studies. This paper contributes by quantifying current grey literature search patterns and associating them with searcher and review characteristics. Further discussion and research into the search approach for grey literature in support of systematic reviews is encouraged.


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Author Biographies

Ahlam A. Saleh, University of Arizona

Information Services Librarian Arizona Health Sciences Library

Melissa A. Ratajeski, University of Pittsburgh

Reference Librarian Health Sciences Library System

Marnie Bertolet, University of Pittsburgh

Assistant Professor Graduate School of Public Health




How to Cite

Saleh, A. A., Ratajeski, M. A., & Bertolet, M. (2014). Grey Literature Searching for Health Sciences Systematic Reviews: A Prospective Study of Time Spent and Resources Utilized. Evidence Based Library and Information Practice, 9(3), 28–50.



Research Articles