Developing optimal search strategies for detecting clinically sound prognostic studies in MEDLINE: an analytic survey.

Nancy L Wilczynski,R Brian Haynes

doi:10.1186/1741-7015-2-23

Abstract

BackgroundClinical end users of MEDLINE have a difficult time retrieving articles that are both scientifically sound and directly relevant to clinical practice. Search filters have been developed to assist end users in increasing the success of their searches. Many filters have been developed for the literature on therapy and reviews but little has been done in the area of prognosis. The objective of this study is to determine how well various methodologic textwords, Medical Subject Headings, and their Boolean combinations retrieve methodologically sound literature on the prognosis of health disorders in MEDLINE.MethodsAn analytic survey was conducted, comparing hand searches of journals with retrievals from MEDLINE for candidate search terms and combinations. Six research assistants read all issues of 161 journals for the publishing year 2000. All articles were rated using purpose and quality indicators and categorized into clinically relevant original studies, review articles, general papers, or case reports. The original and review articles were then categorized as 'pass' or 'fail' for methodologic rigor in the areas of prognosis and other clinical topics. Candidate search strategies were developed for prognosis and run in MEDLINE – the retrievals being compared with the hand search data. The sensitivity, specificity, precision, and accuracy of the search strategies were calculated.Results12% of studies classified as prognosis met basic criteria for scientific merit for testing clinical applications. Combinations of terms reached peak sensitivities of 90%. Compared with the best single term, multiple terms increased sensitivity for sound studies by 25.2% (absolute increase), and increased specificity, but by a much smaller amount (1.1%) when sensitivity was maximized. Combining terms to optimize both sensitivity and specificity achieved sensitivities and specificities of approximately 83% for each.ConclusionEmpirically derived search strategies combining indexing terms and textwords can achieve high sensitivity and specificity for retrieving sound prognostic studies from MEDLINE.

Highlights

Clinical end users of MEDLINE have a difficult time retrieving articles that are both scientifically sound and directly relevant to clinical practice
We report on the information retrieval properties of a broader range of single terms and combinations of terms in MEDLINE for identifying methodologically sound studies on the prognosis of health disorders, developed on a much larger set of journals than previously
Indexing information was downloaded from MEDLINE for 49,028 articles from the 161 journals hand searched

Summary

Introduction

Clinical end users of MEDLINE have a difficult time retrieving articles that are both scientifically sound and directly relevant to clinical practice. BMC Medicine 2004, 2 http://www.biomedcentral.com/1741-7015/2/23 journals, mixed with many preliminary studies This explosion and scattering of information makes it difficult for clinicians to keep up to date with advances in health care [1,2] resulting in most researchable information needs being unmet [3]. One of the six most salient obstacles identified by doctors when attempting to answer questions about patient care is difficulty in selecting an optimal strategy to search for information [6] If databases such as MEDLINE are to be helpful to clinicians, they must be able to retrieve articles that are scientifically sound and directly relevant to the health problem they are trying to solve, without missing key studies or retrieving excessive numbers of irrelevant or misleading studies

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