Table 2.
Demographics of Patients in the Tissue→Airway and Airway→Tissue Subtypes
| Feature | Tissue→Airway | Airway→Tissue | P Value |
|---|---|---|---|
| Number of patients, n (%) | 2,354 (70.4%) | 988 (29.6%) | |
| Sex, M, n (%) | 1,230 (52.3) | 657 (66.5) | P < 0.001 |
| Sex, F, n (%) | 1,124 (47.7) | 331 (33.5) | |
| Age, yr, mean (SD) | 63.18 (8.14) | 63.17 (9.49) | P = 0.92 |
| BMI, kg/m2, mean (SD) | 26.65 (5.43) | 30.54 (6.28) | P < 0.001 |
| FEV1, % predicted, mean (SD) | 53.63 (23.05) | 58.64 (17.74) | P < 0.001 |
| FEV1/FVC ratio, mean (SD) | 0.49 (0.14) | 0.56 (0.11) | P < 0.001 |
| GOLD stage 1, n (%) | 340 (14.4) | 103 (10.4) | P < 0.001 |
| GOLD stage 2, n (%) | 908 (38.6) | 559 (56.6) | |
| GOLD stage 3, n (%) | 680 (28.9) | 273 (27.6) | |
| GOLD stage 4, n (%) | 426 (18.1) | 53 (5.4) | |
| Smoking history, pack-year, mean (SD) | 53.10 (26.42) | 50.35 (26.12) | P = 0.006 |
| Exacerbations, n/yr, mean (SD) | 0.71 (1.23) | 0.62 (1.16) | P = 0.018 |
| Chronic bronchitis, n (%) | 591 (25.1) | 314 (31.8) | P < 0.001 |
| Percent emphysema, mean (SD) | 15.17 (13.67) | 4.08 (6.46) | P < 0.001 |
| Percent fSAD, mean (SD) | 28.89 (11.86) | 20.18 (12.83) | P < 0.001 |
| Percent tissue damage, mean (SD) | 44.06 (20.79) | 24.26 (17.57) | P < 0.001 |
| Airway wall area percentage, mean (SD) | 51.94 (6.81) | 61.77 (6.21) | P < 0.001 |
| Pi10 SRWA, mm, mean (SD) | 2.52 (0.48) | 3.13 (0.56) | P < 0.001 |
| Airway wall thickness, mm, mean (SD) | 1.06 (0.19) | 1.34 (0.21) | P < 0.001 |
Definition of abbreviations: BMI = body mass index; fSAD = functional small airway disease; GOLD = Global Initiative for Chronic Obstructive Lung Disease; SRWA = square root wall area.
We report two sample t tests for continuous variables, chi-squared test for categorical variables, and Mann-Whitney U test results for frequency data. Only patients at Subtype and Stage Inference stages ≥1 were included.