Haye 1998.

Methods	Design: randomised, placebo‐controlled, parallel‐group trial
Participants	Number assigned: 169 adults and elderly (macrolide n = 87, placebo n = 82) Age in years (mean (range)): macrolide: 40.2 (21 to 70), placebo: 43.2 (18 to 68) Setting: primary care
Interventions	Indication: acute maxillary sinusitis Type of macrolide: azithromycin Route: per oral Dose per day: 500 mg Duration of treatment: 3 days Total treatment dose: 1500 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	None stated.
Notes	Concomitant medication: unclear
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Block randomisation
Allocation concealment (selection bias)	Unclear risk	Allocation not described.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Identical‐appearing placebo used.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Participants and clinicians blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No dropout and no participants discontinued treatment due to adverse events
Selective reporting (reporting bias)	Low risk	Adverse events not stated clearly as an outcome. However, standardised ascertainment and adverse events reported.
Other bias	Low risk	None were identified.