Suzuki 2001.

Study characteristics
Methods	Design: randomised, controlled, open‐label, parallel‐group design Duration: 52 weeks Location: Japan (no other information)
Participants	Population: 109 adults with COPD (severity not reported) were randomly assigned to erythromycin (n = 55) or control (n = 54) Baseline characteristics: age (mean years): 70.4; % male (mean): 83.4; FEV₁ (mean): 2.64 (SE 0.05); pack‐years: not reported; former or current smokers: not reported; exacerbation history: not reported Inclusion criteria: mean FEV₁ (L): 1.47 (erythromycin) and 1.30 (placebo); females 13% in erythromycin group vs 18% in placebo group; all study participants were treated with sustained‐release theophylline and inhaled anticholinergic agents Exclusion criteria: diagnosis of bronchiectasis or diffuse pan bronchiolitis
Interventions	Erithromycin (200 to 400 mg daily) No active treatment Allowed co‐medications: sustained‐release theophylline and inhaled anticholinergic agents. Corticosteroids were not allowed
Outcomes	Acute exacerbations of COPD, adverse events
Notes	Funding: not reported Identifier: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation was performed by a random numbers table
Allocation concealment (selection bias)	Low risk	The randomisation list was held independently from the investigators
Blinding of participants and personnel (performance bias) All outcomes	High risk	This study was not blinded
Blinding of outcome assessment (detection bias) All outcomes	High risk	As the study was not blinded, assessment of outcomes would be biased
Incomplete outcome data (attrition bias) All outcomes	Low risk	One participant was excluded due to adverse events of erythromycin; all participants were clearly accounted for
Selective reporting (reporting bias)	Low risk	All pre‐specified outcomes were reported
Other bias	Low risk	No other bias was identified