Beghi 1995.

Methods	Multicentre study, participants were randomised to receive either azithromycin or amoxycillin/clavulanic acid. No blinding. Efficacy was evaluated 10 days after the therapy started
Participants	142 hospitalised or outpatients aged 18 years or more with acute purulent exacerbation of chronic bronchitis. Exclusion criteria: participants treated with other antibiotics 48 hours prior to the study, leucopenia, coagulation disorders, renal dysfunction, HIV/AIDS on immunosuppressive drugs, suspected pneumonia with lung abscess, pleuritis, empyema or active tuberculosis, pregnancy and lactation. Participants: azithromycin group N = 69, amoxycillin/clavulanic acid group N = 73
Interventions	1. Azithromycin (Pfizer) 500 mg single dose daily for 3 days 2. Amoxycillin/clavulanic acid SmithKline Beecham (amoxycillin 875 mg + clavulanic acid 125 mg) twice daily for 8 days
Outcomes	Cure (disappearance of all signs and clinical symptoms of infection by day 10) Improvement (disappearance of only a few signs and/or clinical symptoms) Failure (persistence or worsening of signs and symptoms at days 4 and 10)
Notes	Corticosteroids were allowed, provided this did not exceed 25 mg for prednisolone or its equivalent in both groups. Of the 142 participants, 2 participants dropped out and were not included in the analysis
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	The method of randomisation was not reported
Allocation concealment (selection bias)	High risk	Not mentioned in the article
Blinding (performance bias and detection bias) All outcomes	High risk	No blinding
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants randomised were analysed. 69 in the azithromycin group and 73 in the amoxycillin group
Selective reporting (reporting bias)	Unclear risk	Information not available
Other bias	Unclear risk	Baseline characteristics of the 2 treatment groups were not addressed