Article Text

Comparing the effectiveness of using generic and specific search terms in electronic databases to identify health outcomes for a systematic review: a prospective comparative study of literature search methods
  1. Matt Egan,
  2. Alice MacLean,
  3. Helen Sweeting,
  4. Kate Hunt
  1. Social and Public Health Sciences Unit (SPHSU), MRC/CSO, Glasgow, UK
  1. Correspondence to Dr Matt Egan; m.egan{at}


Objective To compare the effectiveness of systematic review literature searches that use either generic or specific terms for health outcomes.

Design Prospective comparative study of two electronic literature search strategies. The ‘generic’ search included general terms for health such as ‘adolescent health’, ‘health status’, ‘morbidity’, etc. The ‘specific’ search focused on terms for a range of specific illnesses, such as ‘headache’, ‘epilepsy’, ‘diabetes mellitus’, etc.

Data sources The authors searched Medline, Embase, the Cumulative Index to Nursing and Allied Health Literature, PsycINFO and the Education Resources Information Center for studies published in English between 1992 and April 2010.

Main outcome measures Number and proportion of studies included in the systematic review that were identified from each search.

Results The two searches tended to identify different studies. Of 41 studies included in the final review, only three (7%) were identified by both search strategies, 21 (51%) were identified by the generic search only and 17 (41%) were identified by the specific search only. 5 of the 41 studies were also identified through manual searching methods. Studies identified by the two ELS differed in terms of reported health outcomes, while each ELS uniquely identified some of the review's higher quality studies.

Conclusions Electronic literature searches (ELS) are a vital stage in conducting systematic reviews and therefore have an important role in attempts to inform and improve policy and practice with the best available evidence. While the use of both generic and specific health terms is conventional for many reviewers and information scientists, there are also reviews that rely solely on either generic or specific terms. Based on the findings, reliance on only the generic or specific approach could increase the risk of systematic reviews missing important evidence and, consequently, misinforming decision makers. However, future research should test the generalisability of these findings.

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license. See: and

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Supplementary materials


  • To cite: Egan M, MacLean A, Sweeting K, et al. Comparing the effectiveness of using generic and specific search terms in electronic databases to identify health outcomes for a systematic review: a prospective comparative study of literature search methods. BMJ Open 2012;2:e001043. doi:10.1136/bmjopen-2012-001043

  • Contributors ME helped to plan and conduct the study, analyse the findings, led on writing the manuscript and is guarantor for the study. AM, HS and KH helped to plan the study and conduct the study, analyse the findings and provide content and comments on the manuscript. All authors, external and internal, had full access to all of the data (including statistical reports and tables) in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis.

  • Funding ME, AM, HS and KH are core funded by the Medical Research Council (5TK50; 5TK40). ME is also core funded by the Chief Scientist Office (part of the Scottish Government Health Directorates). The authors declare that the research was conducted independently from the funders: the funders played no part in the study design; in the collection, analysis and interpretation of data; in the writing of the report and in the decision to submit the article for publication.

  • Competing interests None.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement The review protocol (including search strategies) and a list of studies included in the final review are available in the supplemental documents submitted with this article. Further data related to the searches are available from the corresponding author at matt{at}