Glumac 2017.

Study characteristics
Methods	Randomised, double‐blind, placebo‐controlled, parallel‐arm trial Study period: March 2015 to January 2016. Published online: 18 May 2017 Number of study centres and locations: single university teaching hospital, the University Hospital of Split, Croatia
Participants	A total of 169 patients scheduled for elective cardiac surgery were enrolled, and 161 participants were included in the analyses. Participants were randomised to receive dexamethasone (n = 80) or placebo (n = 81). Mean age: 63.95 years Sex (female/male ratio): 21.12% No high‐risk population Inclusion criteria: age between 41 years and 84 years, scheduled for elective CABG surgery, heart valve surgery, or combined surgery (CABG and valve surgery) with or without CPB Exclusion criteria: any cerebrovascular incident in the last 3 years; mental illness; visual, hearing, or motor impairment interfering with cognitive assessment; previous cardiac or carotid surgery; LVEF < 35%; adrenal gland disease requiring steroid treatment for longer than 7 days in the past year; alcohol (> 50 g/d or > 500 g/week) or controlled substance abuse; a preoperative MMSE score < 26 points; a preoperative BDI‐II score > 19 points; a preoperative CRP level > 5 mg/L; perioperative stroke; and additional corticosteroid treatment throughout the study period
Interventions	Intervention group: dexamethasone (a single IV bolus of 0.1 mg /kg) Control group: placebo (0.9% NaCl) Timing: 10 hours before the surgery
Outcomes	Primary outcome: POCD on the sixth day after surgery Secondary outcomes: SIRS, PCR, S100, and clinical outcomes (mortality, stroke) Measurements were collected at PODs 1, 2, and 3.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"The pharmacy of the University Hospital of Split prepared the trial medication in computer‐randomised blocks of five indistinguishable, sequentially numbered vials" A random sequence generator was used to determine patient allocation.
Allocation concealment (selection bias)	Low risk	The injections were performed by the attending anaesthesiologist. The pharmacy of the University Hospital of Split prepared the trial medication in computer‐randomised blocks of five indistinguishable, sequentially numbered vials containing either a clear solution of dexamethasone or placebo.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	The participants, their treating physicians, the biochemists, and the investigators were blind to the treatment allocation.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	The participants, their treating physicians, the biochemists, and the investigators were blind to the treatment allocation.
Incomplete outcome data (attrition bias) All outcomes	Low risk	One hundred seventy‐one participants provided consent for this trial. Two participants were excluded because they were unable to complete baseline cognitive test. One hundred sixty‐nine participants completed baseline assessment, and 161 participants were included in the final analyses. Intention‐to‐treat analysis and causes were reported.
Selective reporting (reporting bias)	Low risk	All expected outcomes were reported properly. TRIAL REGISTRATION Clinicaltrials.gov identifier: NCT02767713
Other bias	Low risk	This study was supported by the Clinical Department of Anaesthesiology and Intensive Care, University Hospital of Split, Split, Croatia. The authors declared no conflicts of interest. No other source of bias was identified.