Freeman 2001.

Methods	RCT Randomization method: no details Allocation concealment was adequate sealed envelopes Blinding unclear
Participants	Number of participants/procedures (PDT/ST): 40/40 Gender male/female: PDT: 18/22 (NS) ST: 19/21 (NS) Mean age (years): PDT: 65.44 ± 2.82 (NS) ST: 61.4 ± 2.89 (NS) Population: medical/surgical ICU (patients from the medical, surgical and coronary ICUs) APACHE II Score: PDT: 16.87 ± 0.84 (NS) ST: 17.88 ± 0.92 (NS) SAPS Score: PDT: no details ST: no details Period intubation up to tracheotomy (days): PDT: 12.7 ± 1.1 (NS) ST: 15.6 ± 1.9 (NS) Total number of operators (PDT/ST): no details Experience of the operators (PDT/ST): no details Procedure setting (location PDT performed/location ST performed): bedside/operating room Inclusion and exclusion criteria were clearly defined in the text Inclusion criteria: were as follows: a) age > 18 yrs; b) the necessity of mechanical ventilation for >= 1 week; c) haemodynamic stability (e.g. not requiring vasopressor support); d) ventilatory support of no greater than FIO2 of 0.40 and positive end‐expiratory pressure of 5 cm H2O; and e) no signs of active infection (i.e. afebrile [temperature 38.5°C], white blood cell count under 10,000/mm3 or decreasing by 2000/mm3 per day for the preceding 3 days) Exclusion criteria: included distorted neck anatomy that precluded the operating surgeon from identifying surface landmarks necessary for safely performing PDT, refractory coagulopathy, and patients considered to have a difficult airway for translaryngeal intubation in the event that airway control was inadvertently lost. Also, patients were excluded who were being transported to the operating room for another purpose (such as an orthopedic procedure, abdominal exploration, or gastrostomy tube placement). Children < 16 yr, enlarged thyroid gland, previous tracheostomy, cervical spine fracture, evidence of coagulopathy defined as platelet count < I00,000 ml ‐l or prothrombin time > 1.5 times control Treatment and control groups were not adequately described at entry (gender, age, severity of illness, principle diagnosis)
Interventions	Technique/method: PDT: Ciaglia/Sims, multiple dilator ST: Zollinger/Fenster Monitoring: bronchoscopy Use of bronchoscopic guidance for PDT: yes PDT: sedation and analgesia (e.g. intravenous benzodiazepine, narcotics, and propofol) as well as paralysis if necessary and local anaesthesia (1% lidocaine) ST: adequate anaesthesia
Outcomes	Survival rate (%): PDT: no details ST: no details Days up to decannulation: PDT: no details ST: no details Lowest PaO2 (%): PDT: no details ST: no details Stay in the hospital (days): PDT: 46.7 ± 4.2 (NS) ST: 43.8 ± 3.5 (NS) Operation time (min): PDT: 20.1 ± 2,0 ST: 41.7 ± 3.9 Complication rate, costs Length of follow‐up: PDT: no details ST: no details Lost to follow‐up (total, PDT, open) (%): no details
Notes	No cross‐over
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	No details
Allocation concealment (selection bias)	Low risk	Sealed envelope
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Subject blinded:      Unclear__X__ Physician blinded:    No__X__ Outcome assessor blinded:    Unclear__X__
Incomplete outcome data (attrition bias) All outcomes	Low risk	Outcomes of patients who withdrew or were excluded after allocation were EITHER detailed separately OR included in an intention‐to‐treat analysis OR the text stated there were no withdrawals
Selective reporting (reporting bias)	Low risk	No evidence of selective or incomplete reporting
Other bias	Unclear risk	Treatment and control groups were not adequately described at entry. Patient selection: No _X_ Withdrawls: Unclear _X_ Post‐random exclusion:  Yes _X_ Intension‐to‐treat analysis: Yes _X_
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Subject blinded:      Unclear__X__ Physician blinded:    No__X__
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Outcome assessor blinded:    Unclear__X__