Multivariate logistic regression models for the risk of serious head injury (AIS3+), adjusted ORs, Rhône road trauma registry, 1998–2008, 144 cases and 5153 controls
| M1=‘Cochrane-like’ | M2=‘with more adjustment’ | |
| OR (95% CI) | OR (95% CI) | |
| Helmet | ||
| No | 1.00 | See bottom of table |
| Yes | 0.30 (0.16 to 0.50) | |
| Gender | ||
| Female | 1.00 | 1.00 |
| Male | 1.91 (1.19 to 3.24) | 1.75 (1.08 to 2.99) |
| Age, y | ||
| 0–9 | 0.35 (0.12 to 0.83) | 0.32 (0.11 to 0.79) |
| 10–14 | 0.75 (0.41 to 1.41) | 0.73 (0.39 to 1.39) |
| 15–24 | 0.49 (0.26 to 0.93) | 0.54 (0.28 to 1.04) |
| 25–34 | 0.45 (0.21 to 0.93) | 0.45 (0.21 to 0.94) |
| 35–44 | 1.00 | 1.00 |
| 45–54 | 1.14 (0.56 to 2.28) | 1.00 (0.48 to 2.06) |
| 55–64 | 1.80 (0.89 to 3.60) | 1.42 (0.68 to 2.92) |
| 65+ | 4.99 (2.71 to 9.38) | 4.24 (2.24 to 8.19) |
| Crash opponent | ||
| None | 1.00 | 1.00 |
| Human, animal | 0.94 (0.28 to 2.35) | 0.95 (0.28 to 2.41) |
| Stationary obstacle | 2.03 (1.05 to 3.64) | 2.07 (1.07 to 3.73) |
| Motor vehicle | 3.05 (2.10 to 4.42) | 2.48 (1.67 to 3.68) |
| ISS without head, face, or neck | ||
| 0–3 | 1.00 | |
| 4–8 | 0.52 (0.31 to 0.83) | |
| 9–15 | 2.06 (1.22 to 3.34) | |
| 16–75 | 11.83 (5.12 to 26.93) | |
| Helmet × crash setting | ||
| Not helmeted, rural area | 1.00 | |
| Helmeted, rural area | 0.07 (0.02 to 0.23) | |
| Not helmeted, urban area | 0.48 (0.31 to 0.74) | |
| Helmeted, urban area | 0.16 (0.07 to 0.33) | |
| Place unknown | 0.24 (0.11 to 0.47) | |
The OR of helmeted in urban areas versus not-helmeted in urban areas is 0.34 (95% CI 0.15 to 0.65).
‘Cochrane-like’=adjusted on age, gender, and crash opponent; ‘With more adjustment’=adjusted on age, gender, crash opponent, ISS without head, face or neck, and interaction of helmet with crash setting.
AIS, Abbreviated Injury Scale; ISS, Injury Severity Score.