Fig. 4From: Effect of tiotropium on night-time awakening and daily rescue medication use in patients with COPDAdjusted weekly mean a morning and b evening peak expiratory flow rates. Data are mean ± standard error. The means are adjusted for center effects and baseline. The overall mean is the average over the 13 weekly means for tiotropium versus placebo. *p < 0.05; **p < 0.01; ***p < 0.001 for tiotropium versus placeboBack to article page