He 2010.

Study characteristics
Methods	Design: randomised, double‐blind, placebo‐controlled, parallel‐group design Duration: 26 weeks Location: Affiliated Hospital of Guangxi Medical University, China
Participants	Population: 36 adults with COPD (severity not reported) were randomly assigned to erythromycin (n = 18) or placebo (n = 18) Baseline characteristics: age (mean years): 69 (SD 7.6); % male (mean): 86; % FEV₁ predicted (mean): 43.2 (SD 18.2); pack‐years (mean): 41.7 (SD 18.8); exacerbation history: not reported Inclusion criteria: % FEV₁ predicted between 30 and 70; mean FEV₁ (L): 1.12 (erythromycin) vs 1.02 (placebo); ≥ 10 pack‐year smoking history; no acute exacerbations during the previous 1 month Exclusion criteria: patients with significant other respiratory disorders other than COPD; history of unstable cardiovascular disease; hypersensitivity to macrolides
Interventions	Erythromycin (250 mg 3 times a day) Placebo Allowed co‐medications: present treatment included: inhaled corticosteroid (41%), theophylline (58%), inhaled anticholinergic (52%), inhaled β‐adrenergic (75%)
Outcomes	Analysis of sputum samples (total and differential inflammatory cell counts, sputum bacterial culture), quality of life (SGRQ, SF‐36), number of people with exacerbations, time to first exacerbation, spirometry, adverse events
Notes	Funding: not reported Identifier: ChiCTR‐TRC‐0000036
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomisation was done but was not clearly explained
Allocation concealment (selection bias)	Unclear risk	Allocation concealment was not well explained
Blinding of participants and personnel (performance bias) All outcomes	Low risk	This was a double‐blind trial
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	This is unknown
Incomplete outcome data (attrition bias) All outcomes	Low risk	All outcome data were described using a CONSORT diagram
Selective reporting (reporting bias)	Low risk	All pre‐specified outcomes were reported
Other bias	Low risk	No other bias was identified