Mucolytic drugs v placebo for chronic bronchitis or chronic obstructive pulmonary disease*

Weighted mean
Outcomes at mean 6 monthsMucolyticsPlaceboWeighted mean difference (95% CI)†
Number of exacerbations per patient per month0.090.160.07 (0.05 to 0.08)
Days of illness0.751.310.56 (0.35 to 0.77)
Days of antibiotic use0.671.200.53 (0.31 to 0.76)
Weighted event rates
MucolyticsPlaceboRBI (CI)NNT (CI)
*Abbreviations defined in glossary; weighted mean, RBI, NNT, and CI calculated from data in article.
†All differences favour the mucolytic group.
Patients with no exacerbations60%42%43% (34 to 52)6 (5 to 7)