title: Development of a search filter for identifying studies completed in primary care.
abstract: BACKGROUND
  Identifying articles relevant to primary care is challenging for busy clinicians. Setting specific search strategies can be used to help clinicians find pertinent studies in a timely fashion.
  
  
  OBJECTIVE
  To develop search filters for identifying research studies of relevance to primary care in MEDLINE (OvidSP).
  
  
  METHODS
  We conducted a search of MEDLINE (OvidSP) for articles published in five core medical journals at five yearly intervals. We identified a gold standard set of primary care relevant articles which was divided into two subsets. The first subset was used to identify frequently occurring words and phrases through textual analysis. Search filters were developed from these words and phrases and internally validated against records in the second subset. We evaluated the filters performance in a search for articles on two common primary care conditions in MEDLINE (OvidSP).
  
  
  RESULTS
  Of the 12 045 articles retrieved, 9028 records were reviewed, of which 371 articles were relevant to primary care (gold standard). When the search filters generated from textual analysis were internally validated, filter specificity peaked at 99% with 60% sensitivity, 67% precision and 97% accuracy. When evaluated against a set of articles on two common primary care conditions, the best performing combination search filter specificity maximized at 99.7% with sensitivity reaching 15% (precision 90%; accuracy 89%).
  
  
  CONCLUSIONS
  The best performing combination search filter works well in reducing the number of irrelevant papers retrieved in a MEDLINE (OvidSP) search if a busy clinician needs to focus on research relevant to primary care.
authors.affiliation: The Hospital for Sick Children, Department of Pediatrics, University of Toronto, 555 University Ave, Toronto ON M5G 1X8, Canada, Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG, UK and peter.gill@mail.utoronto.ca.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Gill
authors.affiliation: Bodleian Health Care Libraries, University of Oxford, Oxford, UK.
authors.forename: Nia W
authors.initials: NW
authors.lastname: Roberts
authors.affiliation: Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG, UK and.
authors.forename: Kay Yee
authors.initials: KY
authors.lastname: Wang
authors.affiliation: Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG, UK and.
authors.forename: Carl
authors.initials: C
authors.lastname: Heneghan
mesh_terms: D055317:Evidence-Based Practice / Q000379:methods / Q000592:standards*; D006302:Health Services Research / Q000379:methods / Q000592:standards*; D006801:Humans; D016247:Information Storage and Retrieval / Q000379:methods; D016239:MEDLINE; D046650:Medical Subject Headings; D011320:Primary Health Care / Q000379:methods / Q000592:standards*; D057386:Search Engine / Q000379:methods
keywords: General practice; MEDLINE; information storage and retrieval; medical subject headings; primary health care.