Table 1.
Characteristics of participants with COPD from Norway, Denmark and Australia
| Norway (N=38) |
Denmark (N=36) |
Australia (N=94) |
P-value | Post hoca | |
|---|---|---|---|---|---|
| Sex, male | 24 (63%) | 20 (55%) | 52 (55%) | 0.696 | |
| Age, year | 66 (63–72) | 63 (61–68) | 66 (60–73) | 0.211 | |
| BMI, kg/m2 | 28.4 (24.0–33.1] | 25.6 (22.9–28.0) | 26.0 (22.0–30.5) | 0.066 | |
| Comorbidities, number | 2 (1–3) | 2 (0–2) | 3 (2–4) | <0.001 | AU vs NO=0.009 DK vs AU=0.001 |
| Smoking status | 0.085 | ||||
| Current smoker | 14 (37%) | 13 (36%) | 18 (19%) | ||
| Ex-smoker | 24 (63%) | 23 (64%) | 73 (78%) | ||
| Never smoked | 0 (0%) | 0 (0%) | 3 (3%) | ||
| Smoking, pack years | 24 (15–40) | 40 (25–46) | 45 (31–56) | <0.001 | DK vs NO=0.003 AU vs NO=0.001 |
| FEV1/FVC | 52.8 (44.0–59.0) | 51.5 (43.0–62.5) | 43.5 (34.0–56.0) | 0.002 | AU vs NO=0.008 DK vs AU=0.002 |
| FEV1, liters | 1.32 (0.97–1.82) | 0.92 (0.69–1.11) | 1.13 (0.86–1.50) | <0.001 | DK vs NO=0.001 DK vs AU=0.002 |
| FEV1, % predicted | 50.7 (38.7–63.8) | 32.5 (25.0–41.0) | 44.0 (32.0–62.0) | <0.001 | DK vs NO=0.001 DK vs AU=0.001 |
| FVC, % predicted | 74.7 (67.0–90.0) | 65.5 (48.5–78.0) | 74.0 (62.0–90.0) | 0.011 | DK vs NO=0.013 DK vs AU=0.004 |
| Disease severity | |||||
| GOLD II | 20 (53%) | 3 (8%) | 40 (43%) | <0.001 | |
| GOLD IIII | 11 (29%) | 15 (42%) | 38 (40%) | ||
| GOLD IV | 7 (18%) | 18 (50%) | 16 (17%) | ||
| Use of LTOT, yes | 5 (13%) | 9 (25%) | 12 (13%) | 0.204 | |
| MMRC | 0.642 | ||||
| Score 0 | 2 (5%) | 2 (6%) | 1 (1%) | ||
| Score 1 | 11 (29%) | 10 (28%) | 40 (43%) | ||
| Score 2 | 12 (32%) | 13 (36%) | 27 (29%) | ||
| Score 3 | 11 (29%) | 10 (28%) | 23 (24%) | ||
| Score 4 | 2 (5%) | 1 (3%) | 3 (3%) | ||
| 6MWD, meters | 416 (350–480) | 318 193–383) | 427 (358–480) | <0.001 | DK vs NO=0.001 DK vs AU=0.001 |
| Lowest SpO2 during 6MWD, % | 90 (86–93) | 90 (86–92) | 90 (86–93) | 0.978 | |
| Max HR during 6MWD, beats per minute | 112 (99–127) | 115 (106–122) | 113 (102–122) | 0.889 | |
| SOB end of 6MWD, Borg CR-10 scale | 5 (4–7) | 3 (2–3) | 4 (3–5) | <0.001 | DK vs NO=0.001 DK vs AU=0.002 |
| RPE end of 6MWD, Borg CR-10 scaleb | 4 (2–6) | 3 (2–4) | 3 (2–5) | 0.432 | |
| Gait aid, yes | 2 (5%) | 6 (17%) | 8 (9%) | 0.218 |
Notes: aOnly significant comparisons are listed. bFor the Australian participants, this variable was only calculated for the 33 participants in the iTrain study. Data is presented as median (IQR) for continuous variables, and counts (percentages) for categorical variables. A pack year is defined as twenty cigarettes smoked every day for one year.
Abbreviations: BMI, body mass index; FEV1, forced expiratory volume in the first second; FVC, forced vital capacity; LTOT, long-term oxygen therapy; MMRC, modified version of the Medical Research Council Scale; 6MWD, 6 minutes walking distance; SpO2, peripheral capillary oxygen saturation; HR, heart rate; SOB, rating of perceived shortness of breath; RPE, rating of perceived exertion for leg fatigue; DK, Denmark; NO, Norway; AU, Australia.