A population search filter for hard-to-reach populations increased search efficiency for a systematic review

Chris Cooper, Paul Levay, Theo Lorenc, Gillian M Craig

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)


OBJECTIVES: This article discusses how hard-to-reach population groups were conceptualized into a search filter. The objectives of this article were to (1) discuss how the authors designed a multistranded population search filter and (2) retrospectively test the effectiveness of the search filter in capturing all relevant populations (eg, homeless people, immigrants, substance misusers) in a public health systematic review.

STUDY DESIGN AND SETTING: Systematic and retrospective analysis via a case study. Retrospective analysis of the search filter was conducted by comparing the MEDLINE search results retrieved without using the search filter against those retrieved with the search filter. A total of 5,465 additional results from the unfiltered search were screened to the same criteria as the filtered search.

RESULTS: No additional populations were identified in the unfiltered sample. The search filter reduced the volume of MEDLINE hits to screen by 64%, with no impact on inclusion of populations.

CONCLUSIONS: The results demonstrate the effectiveness of the filter in capturing all relevant UK populations for the review. This suggests that well-planned search filters can be written for reviews that analyze imprecisely defined population groups. This filter could be used in topic areas of associated comorbidities, for rapid clinical searches, or for investigating hard-to-reach populations.

Original languageEnglish
Pages (from-to)554-9
Number of pages6
JournalJournal of Clinical Epidemiology
Issue number5
Early online date1 Apr 2014
Publication statusPublished - 1 May 2014


  • Humans
  • Information Storage and Retrieval
  • Public Health
  • Retrospective Studies
  • Review Literature as Topic
  • Journal Article


Dive into the research topics of 'A population search filter for hard-to-reach populations increased search efficiency for a systematic review'. Together they form a unique fingerprint.

Cite this