Guerra 2008.

Methods	Randomised, controlled, single‐centre study conducted in Brazil Grading of quality: Randomisation = C Blinding = C Intention‐to‐treat analysis = B Follow‐up = D Overall quality grading = C
Participants	120 children aged 14 years or less undergoing adenotonsillectomy. Study and control groups were well matched in terms of age and sex.
Interventions	Postoperative amoxicillin 50 mg/kg/day for 7 days
Outcomes	Primary outcomes: pain, analgesic consumption and secondary haemorrhage Secondary outcomes: fever and time taken to resume normal diet and activities Period of observation: 7 days
Notes	Exclusion criteria: allergy to amoxicillin or haematological disorder. Surgical technique was controlled: all patients underwent dissection, with no use of electrocautery, anaesthetic technique not mentioned as controlled. Follow‐up: 95 (%) patients (43 in the antibiotic group and 52 in the control group) completed follow‐up
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear