King 1996.

Methods	Design: randomised, placebo‐controlled, parallel‐group trial
Participants	Number assigned: 91 adults (macrolide n = 49, placebo n = 42) Age in years (mean ± SD): macrolide: 36.0 ± 13, placebo: 38.2 ± 14.5 Setting: primary care
Interventions	Indication: acute bronchitis Type of macrolide: erythromycin Route: per oral Dose per day: 1000 mg Duration of treatment: 10 days Total treatment dose: 10,000 mg
Outcomes	Adverse events stated as an outcome in trial registration/protocol/paper: unclear Adverse events ascertainment: participant asked Adverse events: data reported Antimicrobial resistance: not reported Death: not reported
Funding sources	Study supported by the Division of Primary Care of the Agency for Health Care Policy and Research. Authors acknowledge supplying company (Parke‐Davis, Morris Plane, New Jersey).
Notes	Concomitant medication: yes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random number table.
Allocation concealment (selection bias)	Unclear risk	Allocation not described.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Identical‐appearing placebo.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinding of participants and clinicians.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	> 20% lost to follow‐up, unclear from which groups.
Selective reporting (reporting bias)	Low risk	Adverse events were stated clearly as an outcome. Standardised ascertainment and adverse events presented.
Other bias	Low risk	None were reported.