An assessment of the efficacy of searching in biomedical databases beyond MEDLINE in identifying studies for a systematic review on ward closures as an infection control intervention to control outbreaks

BACKGROUND The purpose of our study is to determine the value and efficacy of searching biomedical databases beyond MEDLINE for systematic reviews. METHODS We analyzed the results from a systematic review conducted by the authors and others on ward closure as an infection control practice. Ovid MEDLINE including In-Process & Other Non-Indexed Citations, Ovid Embase, CINAHL Plus, LILACS, and IndMED were systematically searched for articles of any study type discussing ward closure, as were bibliographies of selected articles and recent infection control conference abstracts. Search results were tracked, recorded, and analyzed using a relative recall method. The sensitivity of searching in each database was calculated. RESULTS Two thousand ninety-five unique citations were identified and screened for inclusion in the systematic review: 2,060 from database searching and 35 from hand searching and other sources. Ninety-seven citations were included in the final review. MEDLINE and Embase searches each retrieved 80 of the 97 articles included, only 4 articles from each database were unique. The CINAHL search retrieved 35 included articles, and 4 were unique. The IndMED and LILACS searches did not retrieve any included articles, although 75 of the included articles were indexed in LILACS. The true value of using regional databases, particularly LILACS, may lie with the ability to search in the language spoken in the region. Eight articles were found only through hand searching. CONCLUSIONS Identifying studies for a systematic review where the research is observational is complex. The value each individual study contributes to the review cannot be accurately measured. Consequently, we could not determine the value of results found from searching beyond MEDLINE, Embase, and CINAHL with accuracy. However, hand searching for serendipitous retrieval remains an important aspect due to indexing and keyword challenges inherent in this literature.