Fig. 3: Mean forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) before and after bronchodilator use over time (full analysis set for lung function).
Mixed-effects model for repeated measures was used to compare the differences in lung function before and after bronchodilator use at each visit between the two groups. The error bars indicate ± standard error. N-acetylcysteine did not significantly improve FEV1 before bronchodilator use when compared with placebo at 24 months (mean difference: 16 ml, 95% confidence interval, −69 to 100 ml; P = 0.72) and at each visit (P > 0.05 for all comparisons) (A). N-acetylcysteine did not significantly improve FVC when compared with placebo at 12 or 24 months (P > 0.05 for all comparisons) (B).
