IDENTIFYING SYSTEMATIC REVIEWS IN MEDLINE - DEVELOPING AN OBJECTIVE APPROACH TO SEARCH STRATEGY DESIGN

Background: systematic reviews are of increasing importance to health care professionals seeking to provide evidence-based health care, beca use they provide systematically prepared summaries of the current stat e of research knowledge on the effectiveness of health care interventi ons. To be able to make use of them, both researchers preparing system atic reviews and health care professionals need to be able to identify systematic reviews easily. In the past, systematic reviews have been difficult to identify easily among the mass of literature labelled 're views'. Search strategies have been published which were intended to p rovide easier access to systematic reviews and meta-analyses. These st rategies, mostly devised for the MEDLINE database, have been construct ed using the authors' knowledge of the subject area, the databases and past experience. Objective: the objective of this study was to design search strategies based on a more objective approach to strategy cons truction. Methods: word frequencies from the titles, abstracts and sub ject keywords of a collection of systematic reviews of the effective h ealth care interventions were analysed to derive a highly sensitive se arch strategy. Results: the proposed strategy offers 98% sensitivity i n retrieving systematic reviews, while retaining a low but acceptable level of precision (20%). Other strategies with other levels of sensit ivity and precision are also presented.Discussion: this study shows th at a frequency analysis approach can be used to generate highly sensit ive strategies which retain adequate levels of precision when retrievi ng systematic reviews.