Table 2 Relationship between severity of crashes and severity of AHI
AHI 0–5 (n = 140)AHI 6–15 (n = 235)AHI 16–30 (n = 206)AHI >30 (n = 202)
PatientsControlsPatientsControlsPatientsControlsPatientsControls
Total MVC3322833264347135
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 damage1710331520122411
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 damage137271222152118
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 injury35245217266
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).