General characteristics of the cohort
| Characteristics | ALL | AHI <5 | AHI 5–14 | AHI 15–29 | AHI ≥30 | P value |
| Number (%) | 8.580 | 449 (5.2) | 1638 (18.9) | 2280 (26.5) | 4233 (49.2) | |
| Sex (male), n (%) | 4250 (49.5) | 137 (30.5) | 633 (38.9) | 1046 (45.9) | 2434 (57.6) | 0.0001* |
| Age (years) mean (SD) | 53.5 (14.3) | 44.2 (14.5) | 50.3 (13.8) | 53.2 (13.7) | 56 (14) | 0.0001† |
| BMI (kg/m2) mean (SD) | 30.1 (6.3) | 27.3 (5.8) | 28.3 (5.8) | 29.4 (5.9) | 31.4 (6.4) | 0.0001† |
| Neck circumference (cm) mean (SD) | 38.6 (4.2) | 36.1 (3.8) | 37.1 (3.9) | 38 (4) | 39.8 (4.3) | 0.0001† |
| Hypertension n (%) | 4678 (54.5) | 158 (35.1) | 728 (44.7) | 1142 (50.1) | 2650 (62.7) | 0.0001* |
| Snoring n (%) | 6423 (77.6) | 320 (74.5) | 1162 (74.5) | 1668 (75.9) | 3273 (80.1) | 0.49* |
| Witnessed stop breathing n (%) | 5510 (67) | 257 (60.3) | 1010 (64.7) | 1458 (66.5) | 2785 (68.8) | 0.007* |
| Awakening n (%) | 6946 (82) | 358 (80.8) | 1291 (79.7) | 1815 (80.2) | 3482 (83.3) | 0.06* |
| Sleepy in day n (%) | 5673 (66.7) | 293 (66.1) | 1038 (64.1) | 1477 (65.3) | 2865 (68.5) | 0.001* |
| Drowning n (%) | 5625 (66.2) | 294 (66.5) | 1059 (65.6) | 1499 (66.3) | 2773 (66.3) | 0.960* |
| Tired n (%) | 5832 (68.6) | 327 (73.6) | 1091 (67.4) | 1523 (67.4) | 2891 (69.1) | 0.039* |
*χ2 test.
†One-way analysis of variance.
AHI, apnoea–hypopnoea index in events/hour of total sleep time; BMI, body mass index.