Table 3 Mean overall difference between roflumilast and placebo treatment
Mean difference (95% CI)p Value
Sputum characteristics
    Total cell count (×105 cells/g)†−33.6% (−48.8 to −13.8)0.002
    Weight (g)*0.15 (−0.56 to 0.86)0.68
    Viability (%)*−2.0 (−4.4 to 0.3)0.091
    Squamous cell contamination (%)*−1.8 (−6.0 to 2.5)0.41
Cellular inflammation in sputum
    Absolute number of neutrophils†‡−35.5% (−50.7 to −15.6)0.002
    Absolute number of eosinophils†‡−50.0% (−65.8 to −26.8)<0.001
    Absolute number of macrophages†‡−24.4% (−43.9 to 2.0)0.067
    Absolute number of lymphocytes†‡−34.8% (−54.7 to −6.1)0.022
    % Neutrophils*−1.6 (−4.8 to 1.6)0.31
    % Eosinophils†−25.2% (−44.3 to 0.3)0.052
    % Macrophages*1.8 (−0.9 to 4.6)0.19
    % Lymphocytes†−4.1% (−23.8 to 20.7)0.72
Markers of inflammation in sputum supernatant
    IL-8 (ng/ml)†−25.9% (−44.7 to −0.8)0.044
    Neutrophil elastase (μg/ml)†−30.6% (−49.8 to −4.1)0.028
    Lactoferrin (μg/ml)†−29.0% (−57.3 to 17.9)0.18
    ECP (μg/l)†−34.3% (−53.1 to −7.9)0.015
Markers of microvascular leakage in sputum supernatant
    α2-Macroglobulin (ng/ml)†−40.8% (−55.0 to −22.3)<0.001
Systemic markers of inflammation
    E-selectin (ng/ml)†−1.7% (−4.5 to 1.1)0.23
    TNFα (pg/ml)†−10.4% (−19.7 to −0.1)0.047
Lung function
    Pre-bronchodilator FEV1 (ml)*79.5 ml (54.0 to 105.1)<0.001
    Post-bronchodilator FEV1 (ml)*68.7 ml (12.9 to 124.5)0.018
  • IL, interleukin; ECP, eosinophil cationic protein; TNFα, tumour necrosis factor α; FEV1, forced expiratory volume in 1 s.

  • *Mean difference between treatments represents “absolute” difference between roflumilast and placebo treatment for sputum weight, viability, squamous cell contamination, percentage of neutrophils and percentage of macrophages in sputum, and pre- and post-bronchodilator FEV1.

  • †”Relative” difference (mean ratio of change from baseline) for total cell count, number of neutrophils, eosinophils, macrophages and lymphocytes, percentage of eosinophils, percentage of lymphocytes, IL-8, neutrophil elastase, lactoferrin, ECP, α2-macroglobulin, E-selectin and TNFα since these parameters were log-transformed prior to analyses.

  • ‡Unit of absolute cells in sputum ×105 cells/g sputum.