Little 2005a.

Study characteristics
Methods	Randomised controlled trial over 5 years
Participants	807 adults and children aged 3 years and over with cough and at least 1 symptom or sign localising to the lower respiratory tract were included. Participants were recruited from 37 physicians in England. Of the 807 randomised participants, 272 were randomised to delayed antibiotics. Age: for the 272 participants randomised to delayed antibiotics, the average age was 38 years (SD 20); for the 262 participants randomised to immediate antibiotics, it was 40 years (SD 22); and for the 273 participants randomised to no antibiotics, it was 39 years (SD 20). Sex: not provided Exclusion criteria: potential participants were excluded if they were thought to have pneumonia based on focal chest signs, high fever, vomiting or diarrhoea. People were also excluded if they had asthma, chronic or acute lung disease, cystic fibrosis, cardiovascular disease, major psychiatric illness, dementia or previous complications from lower respiratory tract infection including a hospital admission for pneumonia.
Interventions	Participants were randomised to delayed antibiotics (script left at reception and participants instructed to pick up the script after 14 days if required), immediate antibiotics or no antibiotics. Participants in the antibiotic groups were prescribed 250 mg of amoxycillin 3 times a day for 10 days. This dosage was reduced to 125 mg for children aged less than 10 years. For participants who were penicillin allergic, erythromycin 250 mg 4 times a day was used.
Outcomes	Primary outcomes: fever, cough, duration of cough, severity of cough, malaise, duration of malaise, antibiotic use, patient satisfaction Secondary outcomes: complications of disease, hospital admissions, diarrhoea, reconsultation in the 12 months following the index consultation, excluding the first month after the index consultation Outcomes were measured using a daily patient diary
Notes	This study was funded by a grant from the UK's Medical Research Council. The study authors provided original study data, which we used in this review.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated random number tables and block randomisation (block size 6)
Allocation concealment (selection bias)	Low risk	Opaque, sealed envelopes
Blinding (performance bias and detection bias) All outcomes	High risk	Outcome assessor was blinded. Participant and care provider were not blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Missing data were described, and ITT analysis used. Out of 272 participants randomised to delayed antibiotics, 214 were included in the data analysis. Out of 262 participants randomised to immediate antibiotics, 214 were included in the data analysis. Out of 273 participants randomised to no antibiotics, 212 were included in the data analysis.
Selective reporting (reporting bias)	Low risk	Prespecified outcomes were reported
Other bias	Low risk	Funded by government body