NCT00643149.

Methods	‐ RCT ‐ non‐inferiority trial ‐ 15 May 2003 to 22 May 2004
Participants	‐ Number of participants enrolled: target 626 (313 per arm) ‐ Number of participants randomised: 693 ‐ Number of evaluated (treated) participants: 673 (337 azithromycin and 336 amoxicillin) ‐ Number of participants discontinued: 125 (56 azithromycin and 69 amoxicillin) ‐ Age: Children 2 to 12 years ‐ Setting: Multicentre: 33 centres in North America (6 sites in Canada, 19 in US), Latin America (3 sites in Costa Rica, 1 in Guatamala), and India (4 sites); Paediatric outpatients ‐ Acute pharyngitis/tonsillitis based on "erythematous pharyngeal mucosa or thick exudate covering the pharynx and tonsillar area, and at least one of the following signs or symptoms: sore/scratchy throat; pain on swallowing; chills and/or fever; cervical adenopathy; scarlet fever rash on the face and skin folds, or red tongue with prominent papillae ("strawberry tongue")." ‐ Positive rapid antigen detection test or positive culture for GABHS ‐ GABHS pharyngitis/tonsillitis (tested for susceptibility to azithromycin and amoxicillin)
Interventions	‐ Azithromycin SR 60 mg/kg single dose (n = 337); bacteriological per protocol population (n = 245) ‐ Amoxicillin 45 mg/kg twice daily for 10 days (n = 336); bacteriological per protocol population (n = 237)
Outcomes	‐ Bacteriological cure (primary outcome) ‐ Clinical success ‐ Compliance ‐ Adverse events ‐ Time points of assessment: "Test of Cure" at 24 to 28 days after starting study drug; and long term follow‐up on days 38 to 45
Notes	‐ Report provided by Pfizer ‐ Study supported and conducted by Pfizer ‐ Protocol No: A0661071 ‐ Outcomes only reported for "Bacteriological Per Protocol Population", i.e. positive GABHS culture at recruitment or within 48hrs of starting treatment, at least 8 days of study medication and assessment at baseline
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described.
Allocation concealment (selection bias)	Unclear risk	Not described.
Blinding (performance bias and detection bias) All outcomes	Low risk	Placebo matched to the active treatment.
Incomplete outcome data (attrition bias) All outcomes	High risk	‐ In total 693 randomised; 20 were not treated due to insufficient drug supply at study site (no more information given). ‐ Of 673 patients treated 125 patients discontinued (56 in azithromycin group and 69 in amoxicillin group); reasons for discontinuation provided (more dropout due to adverse events in azithromycin arm (4.7% versus 0.9%) and more lack of efficacy in amoxicillin arm (8.3% versus 3.3%)).
Selective reporting (reporting bias)	Unclear risk	All outcomes reported.
Other bias	High risk	Study supported and conducted by Pfizer