Lundeborg 2009.

Study characteristics
Methods	Non‐blinded (open‐label), parallel‐group randomised controlled surgical trial with 6‐month duration of follow‐up
Participants	Setting: secondary care hospital; three clinics in the south‐east region Sweden Sample size: Number randomised: 118 children randomised (37 parents declined participation, 4 excluded due to randomisation error, 10 excluded due to exclusion criteria, 67 children included in study) Number completed: 65 children Participant (baseline) characteristics: Age: 4 to 6 years Gender: 58% males, 42% females Inclusion criteria: children with adenotonsillar hypertrophy and obstructive problems, on the waiting lists for surgery. The decision about surgery was made together with the parents after a clinical examination, with findings consistent with a case history including heavy snoring and/or recurrent tonsillitis. No sleep studies were performed. The families were invited to participate in the research project after the parents received written information about the study and the surgery their child would undergo. Exclusion criteria: treated tonsillitis within 3 months prior to the planned operation, spontaneous recovery from an earlier obstruction, concomitant disease, non‐Swedish speaker
Interventions	Intervention group: tonsillectomy (TE) using cold knife and blunt dissection surgery (n = 33) Comparator group: tonsillotomy (TT) using high‐frequency radiosurgery (n = 34) Use of additional interventions: concurrent adenoidectomy performed in 79% of children. The 14 children who did not have an adenoidectomy were evaluated at surgery to have small, not obstructive adenoids; 7 of them had earlier undergone an adenoidectomy. Concurrent tympanostomy tube placement because of otitis media with effusion (OME) performed in 9% of children
Outcomes	Short‐term outcome (6 months): oral motor function (using the Nordic Orofacial Test‐Screening; NOT‐S), phonology (using a Swedish Phonology Test), perceptual and acoustic measures of vocal function
Notes	Participants lost pre‐trial total: 43% pre‐trial dropout (method of Zelen; 37 declined participation, 4 excluded due to randomisation error, 10 excluded due to exclusion criteria) Participants lost to short‐term follow‐up: 5% at 6 months
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The families were invited to participate in the research project after the parents received written information about the study and the surgery their child would undergo" Quote: "randomised…according to the method of Zelen…"
Allocation concealment (selection bias)	Unclear risk	Method not described
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not blinded
Blinding of outcome assessment (detection bias) All outcomes	High risk	Quote: "Preferably, the evaluations would have been double‐blinded. However, in conjunction with tonsillar problems, a complete blinded assessment is not possible since the NOT‐S requires visualization of the oral cavity including the tonsil area"
Incomplete outcome data (attrition bias) All outcomes	High risk	43% pre‐trial dropout (method of Zelen; 37 declined participation, 4 excluded due to randomisation error, 10 excluded due to exclusion criteria) 5% loss to follow‐up
Selective reporting (reporting bias)	High risk	Quote: "The results are presented as prevalence of symptoms in the TE and TT groups (combined) and in controls."
Other bias	Unclear risk	Baseline characteristics: not balanced for gender in TE group (67% M:33% F) ITT analysis: performed Formal sample size calculations: not performed Use of co‐interventions: similar across groups, concurrent adenoidectomy performed in 76% TE group and 82% TT group, concurrent tympanostomy tube placement performed in 9% TE group and 9% TT group