Chang 2008.

Study characteristics
Methods	Double‐blinded, parallel‐group randomised controlled trial with 6‐day duration of follow‐up
Participants	Setting: single paediatric otolaryngology clinic, Stanford, California, USA Sample size: Number randomised: 69 children (102 screened for eligibility, 12 did not meet inclusion criteria, 21 parents refused randomisation) Number completed: 69 children Participant (baseline) characteristics: Age: 2 to 16 years Gender: 52% males, 48% females Inclusion criteria: scheduled for tonsillectomy and adenoidectomy for OSA/SDB; no further diagnostic criteria provided Exclusion criteria: significant comorbidities, significant history of recurrent/chronic tonsillitis
Interventions	Intervention group: tonsillectomy (TE) using coblation (n = 35) Comparator group: tonsillotomy (TT) using coblation (n = 34) Use of additional interventions: curette adenoidectomy – proportion unclear
Outcomes	Short‐term outcomes (6 days): postoperative pain (child and parent perception), analgesia use, presence of nausea/vomiting, return to normal diet, return to normal activity, days of missed work for parents and complications or readmissions
Notes	Participants lost to follow‐up total: 0%
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "randomly assigned to treatment groups" – no method given
Allocation concealment (selection bias)	Unclear risk	Method not described
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Both the parents and the nurse practitioner who performed the assessments were blinded"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Both the parents and the nurse practitioner who performed the assessments were blinded"
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No statement of dropouts
Selective reporting (reporting bias)	High risk	Two outcomes not reported (analgesia required, days parents required off work)
Other bias	Unclear risk	Baseline characteristics: balanced ITT analysis: performed Formal sample size calculations: performed Use of co‐interventions: not stated across groups