| Methods |
Randomised, open, placebo‐controlled, parallel, multi‐centre (5). Duration 6 months. PP analysis |
| Participants |
169 outpatients with COPD (defined by ATS and ERS); aged 40 to 75 years; FEV₁ < 70% predicted; reversibility < 12% Exclusions: lung cancer, cardiomyopathy, metabolic disease, renal failure, other severe disease. Mean age 66 years; 76% male; mean FEV₁ 1.49 L; 58% predicted; 28% current smokers. 6 dropped out |
| Interventions |
NAC 600 mg daily or placebo |
| Outcomes |
Exacerbations, exacerbation severity, days sick, participant preference, lung function |
| Notes |
Italian study. Open study. COPD, not chronic bronchitis |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
No details |
| Allocation concealment (selection bias) |
High risk |
Investigators aware of order of allocation |
| Blinding of participants and personnel (performance bias)
All outcomes |
High risk |
Open study |
| Blinding of outcome assessment (detection bias)
All outcomes |
High risk |
Open study |
| Incomplete outcome data (attrition bias)
All outcomes |
Unclear risk |
2/85 (2%) dropped out of the intervention group and 4/84 (5%) from the standard care group. Reasons were balanced |
| Selective reporting (reporting bias) |
Low risk |
Reported on main outcomes |
