A search strategy for retrieving articles from the LILACS database in a systematic review of diagnostic accuracy studies: an experimental study

Article type
Authors
1Paulista School of Medicine, Federal University of São Paulo (EPM-UNIFESP), São Paulo
2Science and Technology Institute, São Paulo State University (ICT-UNESP), São José dos Campos
Abstract
Background:
LILACS (Latin American Caribbean Health Sciences Literature) is described in the Cochrane Handbook for Systematic Reviews as one of the resources for systematic reviews of diagnostic test accuracy. Although many studies have already recognized the importance of LILACS in systematic reviews of clinical trials, guidelines on the search strategies for diagnostic studies are lacking. The use of incorrect or incomplete search strategies can impair the retrieval of important studies that are indexed only in LILACS, therefore it is important to develop search strategies that are specific to this database and the type of study.

Objectives:
To propose a new search strategy model to be used in the LILACS (Latin American Caribbean Health Sciences Literature) database for systematic reviews of diagnostic accuracy studies.

Methods:
In this experimental study, we created a search strategy to be used in the LILACS database and then tested the strategy for effectiveness. We then tested the search strategy created for effectiveness in LILACS, in August 2017, using as the gold standard the systematic reviews of diagnostic accuracy studies already published in the Cochrane Library. We registered the number of studies retrieved.

Results:
Of 70 Cochrane Reviews of diagnostic accuracy studies, only 29 had searched the LILACS database and only three had used adapted strategies. These used limited boolean operators only, without modifications in tags or languages. The adapted strategy proposed here was able to retrieve a higher number of studies than the original strategies, especially when using Portuguese and Spanish terms.

Conclusions:
The changes made to the original strategies built for MEDLINE, adapted for LILACS, resulted in a more complex strategy that allowed the retrieval of more studies. These additional studies would have been missed in strategies that were not tailored for LILACS.

Consumer involvement:
There was involvement of researchers testing this new search strategy for the LILACS database to be used in a systematic review of diagnostic accuracy studies.