Impact of searching on LILACS database for Cochrane Systematic Reviews

Article type
Authors
Rada G, Corbalán J, Candia R, Neumann I, María Letelier L
Abstract
Background: Search strategies for Systematic reviews (SR) are intended to identify all relevant articles concerning a specific question. Restricting the search strategy to major databases may introduce bias. On the other hand, the general perception is that searching in minor databases may not be worthwhile, since too few relevant trials are identified and resources needed to evaluate non-English publications are considerable. LILACS is a database which contains articles from Latin-American and Caribbean countries1.
Objectives: To assess if considering LILACS into the searching for trials would increase the amount of articles included in SRs.
Methods: We will analyze new Cochrane SRs published in Issue 2, 2007. A sample of 10% of SRs will be selected randomly. For each SR, the following will be done:
- A structured highly sensitive search strategy for detection of RCTs in LILACS, recently developed at our institution, will be run2. The phases of the strategy concerning population, intervention and comparison will be adapted from each SR's reported strategies for MEDLINE AND EMBASE.
- SRs will be included if: Search strategy is available and LILACS was not used as a source for studies.
- Citations and abstracts retrieved will be scanned by two independent reviewers in order to locate trials that match the SR's reported inclusion criteria. A third reviewer will resolve discrepancies.
- Full text of potential RCTs will be obtained and inclusion will be evaluated separately by the two reviewers. Selected articles will be compared with the original list of included studies and accordingly classified as: 'Not identified in the SR, would have been included if available' or 'Identified in LILACS but also in the original search of the SR'.
Results: Numbers of articles that would have been included and number of SRs that would have benefited from searching LILACS will be reported. Total numbers of citations retrieved and full text ordered will be recorded in order to ponder additional workload of this approach.
Conclusions: Pending results.

References:
1. Available from: URL: www.bireme.br [accessed January 2007].
2. Manríquez J, et al. 14th Cochrane Colloquium. Dublin, Ireland. 2006.