Table 2

Univariate logistic models for survival at 1 year. Odds ratios <1 are associated with a decreasing probability of survival. Odds ratios for continuous variables are for a difference of 5 units* or 1 unit as indicated. Age is fitted as a function with two linear parts; there is no effect on the odds of survival until the age of 50, but after this point the odds of survival decrease by a factor of 0.712 for each 5 year increase in age

Variablep ValueDetailsSurvival (%)Odds ratio95% CI
Age<0.0001Piecewise linear0.712* (0.64–0.79)
Sex 0.063Male78%1
Female68%0.592(0.34–1.02)
Cause 0.106Vehicle accident76%1
Pedestrian/cyclist67%0.638(0.32–1.30)
Fall/jump74%0.862(0.47–1.60)
Other84%1.63(0.81–3.28)
ISS score<0.0001Linear0.720* (0.64–0.81)
GCS total<0.0001Linear1.32 (1.22–1.43)
Pupil reactivity<0.0001Both reacting89%1
Only one reacting67%0.238(0.10–0.57)
Neither reacting38%0.073(0.03–0.17)
CT diagnosis 0.084Visible haematoma76%1
No visible haematoma84%1.67(0.93–2.97)
Alcohol consumed? 0.001No71%1
Yes87%2.68(1.47–4.86)