Prophylactic corticosteroids on postoperative neurocognitive dysfunction and Dexamethasone for Cardiac Surgery (DECS) trial

Dear Editor, We read with interest the publication 'Effect of prophylactic corticosteroids on postoperative neurocognitive dysfunction in the adult population: An updated systematic review, meta-analysis, and trial sequential analysis of randomised controlled trials' by Singh et al.[1] We applaud the authors for their effort to pool study results on the effect of corticosteroids on postoperative neurocognitive disorders, an outcome that is highly relevant to patients yet challenging to operationalise. The authors appear to have overseen the fact that three of the papers that were included in the meta-analysis report data from patients who participated in the same randomised controlled trial, the Dexamethasone for Cardiac Surgery (DECS) trial.[2] Specifically, the work published by Ottens et al.[3] describes a subpopulation of the DECS-trial on-term cognitive outcomes. This subpopulation underwent preoperative baseline neurocognitive testing and follow-ups at 1 month and 1 year with extensive neurocognitive testing. Furthermore, the work published by Sauër et al.[4] describes another subpopulation, in which detailed data on postoperative delirium of 737 patients during the first four postoperative days was analysed. Patients reported by Ottens and Sauër were also included in the main publication on the DECS trial.[3,4] This means that the denominators of the calculations in the pooled analyses need correction as a significant number of patients have been counted twice and, in some cases, three times. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.