Gerber 1990.

Study characteristics
Methods	Randomised controlled trial over 6 months
Participants	113 adolescents and children with sore throat (suspected GABHS) presenting to a private paediatric office in Connecticut, USA Age: the average age of the 63 participants randomised to delayed antibiotics was 9.5 years; of the 50 participants randomised to immediate antibiotics it was 8.1 years Sex:delayed antibiotics group: 30 males, 33 females; immediate antibiotics: 29 males, 21 females Exclusion criteria: hypersensitivity to penicillin, had received penicillin in the previous 72 hours, or had a negative throat culture
Interventions	Both groups received 250 mg of penicillin V 3 times a day for 10 days. Participants randomised to delayed antibiotics received their prescription 48 hours later than those randomised to immediate antibiotics.
Outcomes	Primary outcomes: symptoms were measured but not reported Secondary outcomes: recurrence rate. Symptoms were measured but not reported.
Notes	Funding sources for this trial were not reported. We approached the authors for trial data, but did not receive a reply.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random number table
Allocation concealment (selection bias)	High risk	No information
Blinding (performance bias and detection bias) All outcomes	High risk	No blinding described
Incomplete outcome data (attrition bias) All outcomes	Low risk	Dropouts were described. 63 out of 63 participants in the delayed antibiotic group returned for a follow‐up visit after 4 days. 49 out of 50 participants in the immediate antibiotic group returned for follow‐up visit at 4 days.
Selective reporting (reporting bias)	Unclear risk	Clinical outcomes reported as 1 outcome
Other bias	Unclear risk	Funding not described