The use of systematic reviews in clinical trials and narrative reviews in dermatology: is the best evidence being used?

ABSTRACT

INTRODUCTION AND OBJECTIVES: Systematic reviews -the most comprehensive type of literature review-should be taken into account before a clinical trial or a narrative review on a topic is undertaken. The objective of this study was to describe the use of systematic reviews in clinical trials and narrative reviews in dermatology. MATERIAL AND METHODS: This was a descriptive cross-sectional study. We selected randomized clinical trials and narrative reviews from the dermatological clinical research journals identified as most important (according to impact factor) and from Actas Dermosifiliográficas, and studied the bibliographies to ascertain whether the authors made reference to existing systematic reviews and Cochrane reviews. RESULTS: Of the 72 clinical trials for which a systematic review was available, 24 (33.3%) cited at least 1 review; reference was made to relevant Cochrane reviews in 15.6% of cases and to non-Cochrane reviews in 32%. In the case of the 24 narrative reviews for which a review was available, 10 (41.7%) cited at least 1 review; Cochrane reviews were cited in 20% and non-Cochrane reviews in 35.3%.In the case of Actas Dermosifiliográficas, very few clinical trials were found and the findings for narrative review articles were similar to those observed for the other journals. CONCLUSIONS: Systematic reviews are not often taken into account by the authors of clinical trials and narrative reviews and this may lead to redundant studies and publications. Authors appear to use Cochrane reviews even less than non-Cochrane reviews and are therefore ignoring one of the main sources of available evidence.