| AHI 0–5 (n = 140) | AHI 6–15 (n = 235) | AHI 16–30 (n = 206) | AHI >30 (n = 202) | |||||
| Patients | Controls | Patients | Controls | Patients | Controls | Patients | Controls | |
| Total MVC | 33 | 22 | 83 | 32 | 64 | 34 | 71 | 35 |
| Relative risk (95% CI) | 1.5 (0.9 to 2.5) | 2.6** (1.7 to 3.9) | 1.9** (1.2 to 2.8) | 2.0** (1.4 to 3.0) | ||||
| MVC with minor property damage | 17 | 10 | 33 | 15 | 20 | 12 | 24 | 11 |
| Relative risk (95% CI) | 1.7 (0.8 to 3.4) | 2.2* (1.2 to 4.0) | 1.7 (0.8 to 3.3) | 2.2* (1.1 to 4.4) | ||||
| MVC with major property damage | 13 | 7 | 27 | 12 | 22 | 15 | 21 | 18 |
| Relative risk (95% CI) | 1.85 (0.7 to 4.5) | 2.3 (1.0 to 4.4) | 1.5 (0.8 to 2.8) | 1.2 (0.61 to 2.2) | ||||
| MVC with personal injury | 3 | 5 | 24 | 5 | 21 | 7 | 26 | 6 |
| Relative risk (95% CI) | 0.6 (0.2 to 2.5) | 4.8† (1.8 to 12.4) | 3.0* (1.3 to 7.0) | 4.3** (1.8 to 8.9) | ||||
AHI, apnoea-hypopnoea index; MVC, motor vehicle crash.
Crashes are categorised into one of three severity groups. Relative risks are shown between patients and controls.
*p<0.05; **p<0.005; †p<0.001 (McNemar test).