Table 3

Primary and secondary outcomes

ParameterFCM (n=24)Placebo (n=24)Mean treatment effect of FCM (95% CI)P value
BaselineWeek 1Week 8BaselineWeek 1Week 8
Oxygenation
 Resting SpO2, %94.1±2.394.5±1.993.7±2.394.7±1.694.4±2.094.9±1.70.03 (−0.6 to 0.7)0.93
 Mean nocturnal SpO2, %91.8±2.3a92.3±1.9a92.0±2.1a92.0±2.2b92.3±2.1b92.2±2.5b0.4 (−0.3 to 1.0)0.32
 Nocturnal SpO2 <90%, %14.7±24.2a14.6±18.8a13.8±21.1a16.4±25.6b15.5±23.8b15.8±24.6b−0.3 (−8.1 to 7.6)0.94
 Oxygen desaturation index, per hour8.0±9.2a7.3±10.6a7.8±13.2a6.4±5.5b6.7±5.7b7.5±5.1b−0.8 (−3.5 to 1.9)0.56
 Capillary PO2, kPa9.35±1.13b9.14±1.23b9.19±1.07b9.37±1.19a9.27±1.11a9.04±0.83a−0.11 (−0.45 to 0.23)0.52
 Capillary SO2, %94.6±2.0b94.4±1.9b94.4±1.6b94.6±2.1a94.4±1.6a94.1±1.6a−0.1 (−0.7 to 0.4)0.64
6 min walk test
 Distance, m330±89343±93354±92335±92b337±101b345±104b12.6 (1.6 to 23.5)0.02
 SpO2 change, %−4.1±3.9−4.1±3.8−4.3±5.0−5.6±6.3b−5.0±5.7b−5.2±6.6b−0.1 (−1.7 to 1.5)0.91
 Heart rate change, per minute18.4±16.814.0±15.819.3±17.617.7±14.3b18.1±16.3b17.5±17.8b−2.5 (−9.8 to 4.9)0.50
Symptom and quality of life scores*
 BODE score3.5±2.1a3.3±2.1a3.4±2.1a3.5±2.0c3.5±2.0c3.5±1.9c−0.2 (−0.6 to 0.1)0.22
 COPD Assessment Test14.5±6.314.8±7.816.6±7.316.5±7.115.5±8.018.3±7.50.03 (−1.6 to 1.6)0.97
 St George’s Respiratory Questionnaire total score41.8±15.639.8±15.741.5±15.346.1±17.244.9±18.047.9±18.0−2.3 (−4.8 to 0.1)0.06
 Modified MRC Dyspnoea Scale1.9±0.91.5±0.81.8±1.02.0±1.12.0±0.92.0±1.1−0.4 (−0.7 to −0.1)0.008
 Dyspnoea-12 Score9.0±7.09.5±8.010.9±7.710.1±7.410.5±8.311.1±7.80.6 (−0.9 to 2.1)0.43
 Fatigue Severity Scale33.0±15.731.0±13.732.0±12.639.8±16.037.6±16.841.1±15.2−2.5 (−5.7 to 0.7)0.13
 Hospital Anxiety and Depression Scale-anxiety score4.3±4.14.7±4.24.5±4.65.4±4.15.3±4.15.1±4.00.5 (−0.4 to 1.3)0.31
 Hospital Anxiety and Depression Scale-depression score4.2±2.44.2±2.83.8±2.55.9±3.75.8±3.55.7±3.3−0.1 (−0.7 to 0.6)0.89
 Visual Analogue Scales
  Dyspnoea28.3±19.932.1±25.027.6±21.532.4±23.939.7±25.233.8±23.92.9 (−6.9 to 12.6)0.56
  Cough28.6±25.434.4±26.534.6±27.531.3±28.030.6±26.029.9±22.76.1 (−4.3 to 16.5)0.25
  Sputum production24.9±26.121.4±20.127.5±24.021.2±22.824.9±23.725.6±20.0−2.6 (−10.1 to 4.8)0.48
  Sputum purulence18.9±20.8c17.1±19.4c17.7±21.4c24.4±27.0c19.6±19.4c26.0±20.7c−2.9 (−10.2 to 4.4)0.43
Spirometry
 FEV1, L1.08±0.46a1.04±0.44a1.07±0.44a1.25±0.341.27±0.391.27±0.38−0.03 (−0.08 to 0.01)0.12
 FEV1, % of predicted43.6±16.0a42.3±15.2a43.1±14.5a46.0±15.246.3±16.046.5±16.5−1.3 (−3.0 to 0.4)0.13
 FEV1/FVC, %40.4±10.7a41.3±10.7a41.0±10.0a39.8±10.939.2±11.139.3±10.41.1 (−0.8 to 3.0)0.24
Echocardiography
 Tricuspid regurgitant jet measured, n (%)8 (33.3)8 (33.3)6 (25.0)7 (29.2)7 (29.2)6 (25.0)
 Trans-tricuspid pressure gradient, mm Hg28.8±4.5d26.8±2.7d28.2±2.4d35.2±7.3d35.8±7.6d36.9±12.4d−2.4 (−5.2 to 0.4)0.09
  • All data are reported as mean±SD.

  • Statistical analysis was performed by linear mixed effects modelling.

  • P values and mean treatment effect are given for the fixed effect of ‘status post FCM infusion’.

  • Descriptive data (mean±SD) are reported for participants with a valid measurement at each time point (an=23, bn=22, cn=21, dn=6); cases with partially missing data were excluded. Cases with missing data were still included in the linear mixed effects model.

  • *Scale ranges: BODE 0–10, COPD Assessment Test 0–40, Dyspnoea-12 Score 0–36, Fatigue Severity Scale 9–63, Hospital Anxiety and Depression Scale 0–21, Likert scale 1–7, modified MRC scale 0–4, St George’s Respiratory Questionnaire 0–100, Visual Analogue Scales 0–100. For all scores a lower value is better.

  • COPD, chronic obstructive pulmonary disease; FCM, ferric carboxymaltose; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; MRC, Medical Research Council; PO2, Partial pressure of oxygen; SO2, Oxygen saturation; SpO2, peripheral oxygen saturation.