Chang 2005.

Study characteristics
Methods	Double‐blinded, parallel‐group randomised controlled surgical trial with 6 days of follow‐up
Participants	Setting: Division of Pediatric Otolaryngology, Lucile Packard Children’s Hospital at Stanford and Department of Otolaryngology–Head Neck Surgery, Stanford University School of Medicine, USA Sample size: Number randomised: 128 children (128 children randomised; 27 declined to participate; 101 children received surgery and were included in analyses) Number completed: 101 children Participant (baseline) characteristics: Age: 2 to 10 years Gender: 52% males, 48% females Inclusion criteria: children scheduled to have tonsillectomy and adenoidectomy for obstructive sleep apnoea or sleep‐disordered breathing Exclusion criteria: history of recurrent or chronic tonsillitis or severe co‐morbidities
Interventions	Intervention group: traditional tonsillectomy (TE) performed by electrocautery (n = 53 (n = 49 received surgery and were included in analyses)) Comparator group: intracapsular tonsillectomy (TT) using coblation (n = 75 (n = 52 received surgery and were included in analyses)) Use of additional interventions: concurrent adenoidectomy performed in 100% TE group and 98% TT group 35% of TE group and 29% of TT group received concurrent tympanostomy tube placement 2% of TE group received concurrent frenuloplasty and excision of tongue mucocele 2% of TT group received nasal endoscopy with cauterisation and concurrent direct laryngoscopy
Outcomes	Short‐term outcomes (6 days): mean peri‐operative blood loss, complications and readmissions, postoperative pain, type and frequency of pain medication, presence of nausea or vomiting, proportion of children with poor/fair/good oral intake, mean percentage of normal activity, parental days lost from work
Notes	Participants lost to follow‐up total: 21% (27 declined randomisation; 8% TE group versus 31% TT group)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method not described
Allocation concealment (selection bias)	Unclear risk	Method not described
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "Both the parents and the nurse practitioner performing the assessments were blinded to the treatment assignment." Surgeon not blinded to treatment assignment, unclear at what time the surgeon was notified of treatment allocation
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Both the parents and the nurse practitioner performing the assessments were blinded to the treatment assignment."
Incomplete outcome data (attrition bias) All outcomes	High risk	Significant number of randomised children (21%) not included in analyses; 4/53 (8%) declined to participate in tonsillectomy group versus 23/75 (31%) in tonsillotomy group
Selective reporting (reporting bias)	Unclear risk	No protocol available; insufficient information to permit a judgement of low or high risk
Other bias	Unclear risk	Baseline characteristics: balanced ITT analysis: unclear if performed Sample size calculations: performed Use of co‐interventions: balanced (concurrent adenoidectomy performed in 100%TE and 98% TT)