Brickfield 1986.

Methods	Design: randomised, placebo‐controlled, parallel‐group trial
Participants	Number assigned: 52 adults (macrolide n = 27, placebo n = 25) Age in years (mean): macrolide: 32.0, placebo: 32.5 Setting: primary care
Interventions	Indication: acute bronchitis Type of macrolide: erythromycin base Route: per oral Dose per day: 999 mg Duration of treatment: 7 days Total treatment dose: 6993 mg
Outcomes	Adverse events stated as an outcome in trial registration/protocol/paper: no Adverse events ascertainment: unclear Adverse events: incomplete reporting. However, no contact details for author. Antimicrobial resistance: not reported Death: not reported
Funding sources	Study supported by a grant from the American Academy of Family Physicians. Authors acknowledge supplying companies.
Notes	Concomitant medication: unclear
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Independent company generated numbered, sealed bottles containing tablets of placebo or erythromycin.
Allocation concealment (selection bias)	Low risk	Participants received a numbered, sealed bottle with tablets.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Placebo not described.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Unclear if participants and clinicians were blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	1 participant withdrew from each group, no reasons given.
Selective reporting (reporting bias)	High risk	Adverse events not stated as an outcome, unclear ascertainment and incomplete reporting of adverse events.
Other bias	Low risk	None were identified.