Concerns regarding use of one-tailed tests in the SLED-BD vs. CVVH trial
Northern Clinical School Intensive Care Research Unit, University of Sydney, Pacific Highway, St Leonards, Sydney, NSW 2065, Australia
Critical Care 2012, 16:448 doi:10.1186/cc11490
See related research by Schwenger et al., http://ccforum.com/content/16/4/R140Published: 14 September 2012
First paragraph (this article has no abstract)
In the previous issue of Critical Care, I read with great interest the recent randomized controlled trial comparing sustained low-efficiency dialysis using a single-pass batch dialysis system (SLED-BD) with continuous veno-venous hemofiltration (CVVH) . I congratulate the authors on their undertaking but have serious concerns regarding the majority of their analysis. After each table at the end of the paper, the authors report the use of a 'one-tailed Wilcoxon test' to assess continuous outcomes. I do not believe this use is appropriate.