Optimal search strategies for retrieving systematic reviews from Medline: analytical survey

BMJ. 2005 Jan 8;330(7482):68. doi: 10.1136/bmj.38336.804167.47. Epub 2004 Dec 24.


Objective: To develop optimal search strategies in Medline for retrieving systematic reviews.

Design: Analytical survey.

Data sources: 161 journals published in 2000 indexed in Medline.

Main outcome measures: The sensitivity, specificity, and precision of retrieval of systematic reviews of 4862 unique terms in 782,485 combinations of one to five terms were determined by comparison with a hand search of all articles (the criterion standard) in 161 journals published during 2000 (49,028 articles).

Results: Only 753 (1.5%) of the 49,028 articles were systematic reviews. The most sensitive strategy included five terms and had a sensitivity of 99.9% (95% confidence interval 99.6% to 100%) and a specificity of 52% (51.6% to 52.5%). The strategy that best minimised the difference between sensitivity and specificity had a sensitivity of 98% (97% to 99%) and specificity of 90.8% (90.5% to 91.1%). Highest precision for multiterm strategies, 57% (54% to 60%), was achieved at a sensitivity of 71% (68% to 74%). The term "cochrane database of systematic reviews.jn." was the most precise single term search strategy (sensitivity of 56% (52% to 60%) and precision of 96% (94% to 98%)). These strategies are available through the "limit" screen of Ovid's search interface for Medline.

Conclusions: Systematic reviews can be retrieved from Medline with close to perfect sensitivity or specificity, or with high precision, by using empirical search strategies.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Information Storage and Retrieval / methods*
  • Information Storage and Retrieval / standards
  • MEDLINE / standards*
  • Medical Subject Headings
  • Review Literature as Topic*
  • Sensitivity and Specificity