How Often Do Comparative Randomised Controlled Trials in the Field of Eczema Fail to Directly Compare the Treatments Being Tested?

Abstract

The objective of the study was to identify all parallel design randomised controlled trials (RCTs) comparing treatments for eczema in recent dermatology literature that have failed to report a between-group analysis. The GREAT database () was searched to identify parallel group RCTs comparing two or more interventions published in the English language in the last decade, 2004 to 2013. The primary outcome was the number of studies that had not reported a between-group analysis for any of the outcomes. Where possible we re-analysed the data to determine whether a between-group analysis would have given a different conclusion to that reported. Out of a total of 304 RCTs in the study period, 173 (56.9%) met the inclusion criteria. Of the 173 eligible studies, 12 (6.9%) had not conducted a between-group analysis for any of the reported outcomes. There was no clear improvement over time. Five of the eight studies that were re-analysed yielded non-significant between-group differences yet reported significant within-group comparisons. All but one of the 12 studies implied that the experimental intervention was successful despite not undertaking any between-group comparisons. Although the proportion of all RCTs that fail to report an appropriate between-group analysis is small, the fact that any scientist who purports to compare one treatment against another then chooses to omit the key comparison statistic is worrying.

What's new in atopic eczema? An analysis of systematic reviews published in 2015. Part 1: epidemiology and methodology

“…Finally, a review on the quality of reporting AE trials by Ratib et al 20 found that 12% of AE RCTs published between 2004 and 2013 incorrectly reported withingroup rather than between-group differences, as would be appropriate for a comparison of two interventions, leading to misrepresentation of the importance of the trial findings. The authors supported mandatory dermatology trial registration entailing declaration of study outcomes prior to start of recruitment.…”

What's new in atopic eczema? An analysis of systematic reviews published in 2015. Part 2: prevention and treatment

“…Tan et al ., who strictly defined AE for inclusion in the review, found no RCTs. By contrast, Ma and colleagues reported 5 RCTs (four by the same research group), and 1 prospective observational study, which had a total of 170 participants. Although itch measurements were lower in the acupuncture groups, the studies were small, and the acupuncture regimens and control arms varied significantly.…”