Table 1 Baseline characteristics of the study population by FVC% predicted at baseline
Characteristic | Total sample N = 204 | Predicted FVC% at baseline | |||
|---|---|---|---|---|---|
FVC < 50% N = 22 | FVC 50–80% N = 152 | FVC > 80% N = 30 | p value | ||
Sex, male, n (%) | 157 (77.0%) | 18 (81.8%) | 120 (78.9%) | 19 (63.3%) | 0.1516 |
Age (years), mean (SD) | 70.80 (7.60) | 70.32 (8.52) | 71.36 (7.21) | 68.33 (8.54) | 0.1992 |
Employment status (active workers), n (%) | 24 (11.8%) | 2 (9.1%) | 14 (9.2%) | 8 (26.7%) | 0.0232 |
BMI (kg/m2), mean (SD)† | 28.13 (3.97) | 27.15 (3.73) | 28.29 (3.88) | 28.06 (4.62) | 0.5682 |
Occupational and/or environmental exposure to risk factors, n (%) | 97 (47.5%) | 10 (45.5%) | 75 (49.4%) | 12 (40.0%) | 0.7718 |
Smoking habit, n (%) | 0.5300 | ||||
Non smokers | 64 (31.4%) | 8 (36.4%) | 48 (31.6%) | 8 (26.7%) | |
Former smokersa | 135 (66.2%) | 14 (63.6%) | 101 (66.4%) | 20 (66.7%) | |
Smokers | 5 (2.4%) | 0 (0.0%) | 3 (2.0%) | 2 (6.6%) | |
Time since IPF diagnosis to baseline visit (years), mean (SD) | 1.92 (1.85) | 2.00 (1.69) | 1.95 (1.91) | 1.73 (1.67) | 0.6416 |
Lung function, mean (SD) | |||||
FVC % predicted | 65.78 (14.42) | 41.96 (5.83) | 64.66 (8.42) | 88.94 (8.35) | < 0.0001 |
FVC annual rate of decline (%) | 5.12 (5.84) | 8.40 (6.24) | 4.68 (5.70) | 4.50 (5.83) | 0.1055 |
DLco-c % predicted† | 49.99 (17.39) | 36.17 (12.27) | 50.29 (17.36) | 57.83 (15.29) | < 0.0001 |
Six-minute walk test, mean (SD)† | |||||
Distance (m), mean (SD) | 443.70 (101.32) | 376.45 (122.65) | 449.78 (92.71) | 472.55 (103.70) | 0.0036 |
Need for oxygen, n (%) | 17 (10.7%) | 5 (25.0%) | 12 (10.3%) | 0 (0.0%) | 0.0307 |
Comorbidities associated with IPF, n (%)b | 147 (72.1%) | 18 (81.8%) | 110 (72.4%) | 19 (63.3%) | 0.3358 |
Arterial hypertension | 71 (48.3%) | 7 (38.9%) | 58 (52.7%) | 6 (31.6%) | 0.1629 |
Diabetes | 35 (23.8%) | 4 (22.2%) | 26 (23.6%) | 5 (26.3%) | 0.9482 |
Gastroesophageal reflux | 32 (21.8%) | 2 (11.1%) | 27 (24.5%) | 3 (15.8%) | 0.4268 |
Coronary heart disease | 21 (14.3%) | 4 (22.2%) | 16 (14.5%) | 1 (5.3%) | 0.3447 |
Sleep apnoea-hypopnea syndrome | 19 (12.9%) | 3 (16.7%) | 15 (13.6%) | 1 (5.3%) | 0.5468 |