Table 2.
Results of spirometry in the cohort completing spirometry with adequate reproducible blows and demispan available for calculation of predicted blows (n=737)
| Men (n=293) | Women (n=444) | All (n=737) | p Value* | |
|---|---|---|---|---|
| Actual spirometry median (IQR) | ||||
| FEV1 (l/s) | 1.8 (1.4–2.2) | 1.2 (1.0–1.5) | 1.4 (1.1–1.8) | <0.001† |
| FVC (l/s) | 2.7 (2.2–3.2) | 1.8 (1.4–2.1) | 2.0 (1.6–2.6) | <0.001† |
| FEV1/FVC | 0.7 (0.6–0.8) | 0.7 (0.6–0.8) | 0.7 (0.6–0.8) | 0.006† |
| PEF (L/m) | 441 (323–604) | 283 (196–362) | 328 (233–450) | <0.001† |
| % predicted median (IQR) | ||||
| FEV1 | 78.8 (62.4–94.3) | 83.4 (68.1–98.8) | 81.5 (65.6–97.1) | 0.008† |
| FVC | 83.4 (70.3–99.6) | 96.6 (79.1–113.7) | 90.8 (74.1–108.4) | <0.001† |
| Spirometry % (N) | ||||
| Normal | 28.0 (82) | 33.3 (148) | 31.2 (230) | 0.108‡ |
| Restrictive | 13.7 (40) | 16.2 (72) | 15.2 (112) | |
| Obstructive | 58.4 (171) | 50.5 (224) | 53.6 (395) | |
| Grading of obstructive spirometry§ % (N) | ||||
| Mild | 35.7 (61) | 43.3 (97) | 40.0 (158) | 0.059¶ |
| Moderate | 46.8 (80) | 45.1 (101) | 45.8 (181) | |
| Severe | 14.6 (25) | 9.8 (22) | 11.9 (47) | |
| Very severe | 2.9 (5) | 1.8 (4) | 2.3 (9) | |
| FEV1 % (N) | ||||
| Below LLN | 25.9 (76) | 13.3 (59) | 18.3 (135) | <0.001** |
| Normal range | 73.7 (216) | 85.6 (380) | 80.9 (596) | |
| Above ULN | 0.3 (1) | 1.1 (5) | 0.8 (6) | |
| FEV1 Z-score | ||||
| median (IQR) | 1.0 (0.2–1.7) | 0.6 (0.0–1.2) | 0.8 (0.1–1.4) | <0.001† |
| FVC % (N) | ||||
| Below LLN | 21.2 (62) | 9.2 (41) | 14.0 (103) | <0.001‡ |
| Normal range | 77.1 (226) | 86.3 (383) | 82.6 (609) | |
| Above ULN | 1.7 (5) | 4.5 (20) | 3.4 (25) | |
| FVC Z-score | ||||
| median (IQR) | 0.9 (0.0–1.5) | 0.1 (−0.6–0.9) | 0.4 (−0.4–1.2) | <0.001† |
| Oxygen saturation | ||||
| median (IQR) | 97 (96–98) | 97 (96–98) | 97 (96–98) | 0.513† |
*Comparison of men and women.
†Mann–Whitney U test.
‡χ2 test.
§This is based on the 395 participant subsample with obstructive spirometry.
¶Kruskal–Wallis test.
**Fisher's exact test.
LLN, lower limit of normal; PEF, peak expiratory flow; ULN, upper limit of normal.