Multivariate logistic regression models for the risk of any head injury (AIS1+), adjusted ORs, Rhône road trauma registry, 1998–2008, 1471 cases and 5153 controls
| M1=‘Cochrane-like’ | M2=‘with more adjustment’ | |
| OR (95% CI) | OR (95% CI) | |
| Helmet | ||
| No | 1.00 | 1.00 |
| Yes | 0.76 (0.65 to 0.89) | 0.69 (0.59 to 0.81) |
| Gender | ||
| Female | 1.00 | 1.00 |
| Male | 1.13 (0.98 to 1.30) | 1.14 (0.99 to 1.33) |
| Age, y | ||
| 0–14 | 1.37 (1.12 to 1.70) | 1.32 (1.07 to 1.63) |
| 15–24 | 0.86 (0.69 to 1.08) | 0.83 (0.66 to 1.04) |
| 25–34 | 0.82 (0.64 to 1.05) | 0.78 (0.61 to 1.00) |
| 35–44 | 1.00 | 1.00 |
| 45–54 | 1.19 (0.91 to 1.55) | 1.21 (0.92 to 1.60) |
| 55+ | 1.68 (1.31 to 2.15) | 1.69 (1.30 to 2.18) |
| Crash opponent | ||
| None | 1.00 | 1.00 |
| Human, animal | 1.33 (1.01 to 1.73) | 1.16 (0.87 to 1.52) |
| Stationary obstacle | 1.09 (0.86 to 1.37) | 1.05 (0.82 to 1.34) |
| Motor vehicle | 1.85 (1.60 to 2.12) | 1.68 (1.44 to 1.95) |
| ISS without head, face, or neck | ||
| 0–3 | 1.00 | |
| 4–8 | 0.29 (0.25 to 0.35) | |
| 9–15 | 0.47 (0.36 to 0.62) | |
| 16–75 | 1.55 (0.80 to 2.97) | |
| Road type | ||
| Major road | 1.55 (1.17 to 2.04) | |
| Local road | 1.00 | |
| Off road | 0.90 (0.75 to 1.08) | |
| Unknown | 1.28 (1.04 to 1.56) | |
| Crash setting | ||
| Urban | 1.00 | |
| Rural | 1.30 (1.11 to 1.53) | |
| Unknown | 0.75 (0.60 to 0.93) | |
‘Cochrane-like’=adjusted on age, gender, and crash opponent; ‘With more adjustment’=adjusted on age, gender, crash opponent, ISS without head, face or neck, road type, and crash setting.
Age is in six categories only, otherwise the ‘Cochrane-like’ model is rejected (test of fit).
AIS, Abbreviated Injury Scale; ISS, Injury Severity Score.