These authors contributed equally to this work.
Developing a geographic search filter to identify randomised controlled trials in Africa: finding the optimal balance between sensitivity and precision
Article first published online: 30 MAR 2011
© 2011 The authors. Health Information and Libraries Journal © 2011 Health Libraries Group
Health Information & Libraries Journal
Volume 28, Issue 3, pages 210–215, September 2011
How to Cite
Pienaar, E., Grobler, L., Busgeeth, K., Eisinga, A. and Siegfried, N. (2011), Developing a geographic search filter to identify randomised controlled trials in Africa: finding the optimal balance between sensitivity and precision. Health Information & Libraries Journal, 28: 210–215. doi: 10.1111/j.1471-1842.2011.00936.x
- Issue published online: 10 AUG 2011
- Article first published online: 30 MAR 2011
- Received 30 June 2010; Accepted 9 March 2011
- bibliographic databases;
- clinical trials;
- health information needs;
- search strategies
Background: Research on identifying trials using geographic filters is limited.
Objectives: To test the sensitivity and precision of a filter to identify African randomised controlled trials (RCTs).
Methods: We searched medline and embase for RCTs published in 2004 using a Cochrane filter for RCTs. The search was limited to HIV/AIDS but irrespective of location. Two investigators independently identified African RCTs from the retrieved records forming a reference set. We then repeated the search using an African geographic filter comprising country and regional terms forming the filter set. We compared the sensitivity and precision of the sets.
Results: The medline reference set comprised 1799 records with 23 African RCTs; for embase, the reference set comprised 763 records with 37 African RCTs. The medline filter set comprised 180 records with 17 African RCTs; the embase filter set comprised 98 records with 27 African RCTs. Sensitivity of the filter was 74% (medline) and 73% (embase). Addition of the filter improved precision from 1.3% to 9.4% (medline) and from 5% to 28% (embase).
Conclusion: The African filter improved precision with some loss in sensitivity. Incomplete reporting of trial location in electronic bibliographic records restricts efficiency of geographic filters. Prospective trial registration should alleviate this.