Mapping Cochrane systematic reviews: the next appeal for the evidence-based medicine age

Article type
Authors
El Dib R1, Villas Boas P2, Spagnuolo R2, Kamegasawa A2, Braz L2, Valle A2, Jorge E2, Yoo H2, Cataneo A2, Côrrea I2, Fukushima F2, Nascimento P2, Módolo N2, Teixeira M2, Vidal E2, Daher S2, Evidence- Based Medicine Working Group T2
1UNESP—Univ Estadual Paulista, Brazil and; McMaster Institute of Urology, McMaster University, Canada
2UNESP—Univ Estadual Paulista, Brazil
Abstract
Background: The aims of the Cochrane systematic reviews are to make readily available up-to-date, accurate information about the effects of healthcare offering consistent evidences and presence of straightforward recommendation. In 2004, we evaluated the conclusions from Cochrane systematic reviews of randomized controlled trials in terms of their recommendations for clinical practice and founded that 47.83% of them have insufficient evidence for clinical practice.

Objectives: We proposed then to reanalyse the reviews to evaluate whether this percentage had significantly decreased.

Methods: A cross-sectional study of systematic reviews-published in the Cochrane Library (issue 7, 2011) was conducted. We randomly selected and analysed completed reviews across all 52 Cochrane Collaborative Review Groups.

Results: We analysed 1128 completed systematic reviews. Of these, 44, 33% concluded that the interventions studied were likely to be beneficial. In total, 46, 28% of the reviews reported that the evidence did not support either benefit or harm, of which 47, 83% recommended additional studies.

Conclusions: Systematic reviews have a great structure but they lack on the ‘fuel’ that feeds them, the clinical trials. A Cochrane’s appeal was the first step to establish good evidence for decision making in health care. The next appeal, as per El Dib’s words, is ‘A great criticism of the Evidence-Based Medicine age is that we have not produced higher-quality primary studies, with worldwide centers’ participation and in accordance to the Cochrane’s protocols, to cover all those systematic reviews that did not offer enough evidence for clinical practice.’