Koksal 2004.

Methods	Randomized controlled trial Setting: Istambul University Cerrahpasa Medical Faculty, Istambul, Turkey Sample size: not estimated by the authors
Participants	‐ 60 patients mechanically ventilated for more than 48 hours ‐ Patients with endocrine or immune system disease, patients with malignant disorders, patients who were on sympathomimetic agents or steroids were excluded from the study ‐ Mean age: 74 years ‐ Male: 28; Female: 32 ‐ Mechanical ventilation time: not reported ‐ Mean APACHE II score: 18.5 ‐ There were no differences between the groups in age, weight, gender and APACHE II
Interventions	1‐ T‐piece (4L/min) (n=20) 2‐ Pressure support ventilation 10 cmH2O and PEEP of 5 cmH2O (n=20) 3‐ CPAP of 5 cmH2O (n=20)
Outcomes	1‐ Successful extubation 2‐ Reintubation 3‐ Plasma insulin 4‐ Plasma cortisol 5‐ Blood glucose 6‐ Urine VMA
Notes	The durations of interventions (TT, PSV and CPAP) were 2 hours The intervention 3 was not considered for analysis in this review Weaning was considered unsuccessful if reintubation was required within 48 hours and these patients were excluded from the analysis for the laboratory variables (outcomes 3 to 6) We excluded the outcomes 3 to 6 from the review
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomization was achieved by pulling slips of paper labelled I, II, III from a bag (20 pieces per group) (data reported by first author)
Allocation concealment (selection bias)	Unclear risk	Not reported
Selective reporting (reporting bias)	Low risk	Two outcomes were clinically relevant (extubation success and reintubation) and there was neither explicit nor implicit preference from authors to one or another method that could force then to elect specific outcomes
Other bias	Low risk	None suspected
Free of detection bias ?	Low risk	Two persons who collected and analysed the data for the study did not know which group the patient belonged to (double blind) ( data reported by author)
Free of attrition bias?	Low risk	There was no withdrawal of data considered for this review (successful extubation and reintubation)