A survey of searching CBM and LILACS databases in Cochrane Systematic Reviews

Article type
Authors
Chen Y1, Yao L2, Wang Z2, Liang H2, Liang F2
1Evidence-Based Medicine Center of Lanzhou University, China
2School of Basic Medical Sciences of Lanzhou University, China
Abstract
Background: Ideally, unbiased systematic reviews should always search and include all relevant trials, independent of the language of publication. The inclusion of studies published in languages other than English could help avoid bias. The Cochrane Handbook recommends systematic reviewers to search CBM (Chinese Biomedical Literature Database) and LILACS (Latin American and Caribbean Health Science) besides MEDLINE, EMBASE and Cochrane Central Register of controlled Trials (CENTRAL).

Objectives: To investigate how many Cochrane Systematic Reviews searched CBM and LILACS Database.

Methods: We searched the full text in the Cochrane Database of Systematic Reviews (4594 reviews and 2008 protocols in Issue 4, 2011) using the terms 'CBM’, 'Chinese Biomedical Literature Database’, 'LILACs', 'Latin American and Caribbean Health Science’. We then screened all included studies.

Results: 222 (3%) systematic reviews or protocols searched CBM and 1353 (20%) systematic reviews or protocols searched LILACS. Only 41 (0.6%) systematic reviews or protocols searched both CBM and LILACS from the year 2002. Among these 41 systematic reviews, 28 (68%) have Chinese authors and 13 (32%) are about Traditional Chinese Medicine.

Conclusions: Although searching for trials in CBM and LILACS has been demonstrated to improve the quality of systematic reviews, less than 1% of published Cochrane systematic reviews searched both of them. The number of Cochrane systematic reviews that searched LILACS is 6-fold the number of Cochrane reviews that searched CBM. We suggest more Cochrane systematic review authors search non-English databases, such as CBM and LILACS.