Should methodological filters for diagnostic test accuracy studies be used in systematic reviews of psychometric instruments? a case study involving screening for postnatal depression

A reference set of six relevant studies was derived from a forward citation search via Web of Knowledge. The performance of the 'target condition and index test' method recommended by the Cochrane DTA Group was compared to two alternative strategies which included methodological filters. Outcome measures were total citations retrieved, sensitivity, precision and associated 95% confidence intervals (95%CI).The Cochrane recommended strategy and one of the filtered search strategies were equivalent in performance and both retrieved a total of 105 citations, sensitivity was 100% (95% CI 61%, 100%) and precision was 5.2% (2.6%, 11.9%). The second filtered search retrieved a total of 31 citations, sensitivity was 66.6% (30%, 90%) and precision was 12.9% (5.1%, 28.6%). This search missed the DTA study with most relevance to the DTA review.The Cochrane recommended search strategy, 'target condition and index test', method was pragmatic and sensitive. It was considered the optimum method for retrieval of relevant studies for a psychometric DTA review (in this case for postnatal depression). Potential limitations of using filtered searches during a psychometric mental health DTA review should be considered.The advent of systematic reviews has generated challenges to develop optimum methods with which to identify studies from electronic bibliographic databases [1]. There is a great deal of expertise in this matter for systematic reviews of randomised trials [2]. However the design of optimum information retrieval strategies for recent developments such as Diagnostic Test Accuracy (DTA) reviews is not yet resolved; challenges that exist when searching for DTA studies have been acknowledged and include the design of DTA search strategies and selection of appropriate filters [3-5]. DTA studies are important for the assessment of new or existing screening tests; the accuracy of a screening test is assessed by comparing the test to a 'gold standard' to examine if the screening test