IDENTIFYING RELEVANT DIAGNOSTIC STUDIES IN MEDLINE - THE DIAGNOSTIC-VALUE OF THE ERYTHROCYTE SEDIMENTATION-RATE (ESR) AND DIPSTICK AS AN EXAMPLE

Objective. We aimed to examine sensitivity and positive predictive val ue of Medline searching for diagnostic studies, relevant for the prima ry health care setting. Method. Results of Medline searches were compa red with a reference standard collection of studies on two subjects, t he diagnostic value of ESR in discriminating between 'pathology' and ' no pathology', and the dipstick method in diagnosing urinary tract inf ections. The main outcome measures were sensitivity (proportion of the total number of reference standard diagnostic studies that could be i dentified by the search) and positive predictive value (proportion of the total number of publications retrieved by Medline that were incorp orated in the reference standard). Results. The combined MeSH and free text search was more sensitive than MeSH term searching only, for both the ESR and the dipstick search. With this combined search sensitivit ies of 0.91 and 0.98 and predictive values of 0.10 and 0.68 were found for ESR and dipstick respectively. By restricting the search with key words describing the primary health care setting the predictive values increased to 0.72 and 1.00 but sensitivity dropped to 0.10 and 0.07 ( ESR and dipstick respectively). Conclusion. Combining freetext and MeS H term searching, without restriction to the primary health care setti ng, is a valuable strategy in systematically searching for available e vidence on the value of a diagnostic test in the scope of a specific d isease. The predictive value seems to depend on the breadth of the dis ease area. Medline should provide a term such as 'diagnostic evaluatio n study' to be used in the limit field Publication Type to specify dia gnostic studies.