Indexing of clinical trials in LILACS: Assessment of 721 articles published in cardiology journals

Abstract

Systematic reviews are considered the highest level of evidence for decision making in health care issues. One of the first steps
of a SR involves identifying all relevant clinical trials on the topic of interest. However, the retrieval of clinical trials in a database
partially depends on the article indexing quality. The aim of this article is to evaluate the adequacy of indexing of clinical trials
as a publication type in the LILACS database in a sample of articles published in cardiology journals. This cross-sectional study
analyzed the indexing quality of clinical trials published between 2008 and 2009 in cardiology journals indexed in LILACS. Two
independent reviewers identified and reclassified all original studies published in these journals as being clinical trials or other
types of studies. The result of their classification was compared with the indexing publication type produced by LILACS. A total
of 721 articles published in 11 cardiology journals were included. The reviewers classified 63 articles as clinical trials; 44 of these
were correctly indexed in LILACS, while 19 were indexed as other types of studies (false negatives). The reviewers classified 658
articles as non-clinical trials; 651 were correctly indexed and 7 were incorrectly indexed in LILACS as being clinical trials (false
positives). The sensitivity, specificity and global accuracy of LILACS indexing were 69.8%, 98.9% and 96.4% (695/721), respectively.
Almost one third of the clinical trials published in LILACS-indexed Cardiology journals are not adequately indexed. The indexing
quality of the studies published in these journals must be improved.