Acute traumatic brain injury: clinical features can help predict mortality

Clinical bottom line (level 1a)

  1. A quarter of patients with severe head injury are dead within a year.
  2. Patients are at increased risk of dying if they have
    • a haematoma on CT
    • neither pupil reacting
    • old age
    • a low Glasgow Coma Scale
    • a high Injury Severity Score
  3. A nomogram based on these 5 factors can be used to predict outcome following severe head injury.
Signorini et al: Journal of Neurology, Neurosurgery and Psychiatry 1999; 66: 20-25
Expires November 2003

The study

Inception cohort study with objective outcomes, adjusted for confounding factors, validated in an independent set of patients.

Setting: regional trauma centre, UK

372 patients (aged mean 42, 78% male) with traumatic brain injury and a Glasgow Coma Scale = 12 or 13-15 with an injury severity score = 16

Excluded if
  • aged < 14



    • Factors studied:
  • age, sex, GCS, cause of injury, injury severity score, pupil response, brain CT result, prior consumption of alcohol
  • neither pupil reacting
  • age (per 5 years)
  • injury severity score (per 5 units)
  • no visible haematoma on CT
  • GCS total (per unit)




    • Multivariate regression analysis performed on prognostic factors

    98% followed for 1 year
    Outcomes studied:
  • death

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)    		 NNF
    (95% CI)
    death 12 months 87/372 23%
    (19% to 28%)    		 4
    (4 to 5)

    prognostic factor for
    death     		time to outcome control rate (%) adjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    neither pupil reacting 12 months 87/372
    (23.4%)     		0.168
    (0.06 to 0.50)     		5
    (5 to 10)
    age (per 5 years) 12 months 87/372
    (23.4%)     		0.545
    (0.43 to 0.69)     		11
    (8 to 17)
    injury severity score (per 5 units) 12 months 87/372
    (23.4%)     		0.737
    (0.60 to 0.91)     		20
    (13 to 61)
    no visible haematoma on CT 12 months 87/372
    (23.4%)     		3.53
    (1.43 to 8.73)     		-4
    (-14 to -2)
    GCS total (per unit) 12 months 87/372
    (23.4%)     		1.31
    (1.12 to 1.53)     		-19
    (-48 to -12)

    • A nomogram was created using these 5 predictors and validated in an independent set of 520 patients. In 15% of cases the predicted outcome differed from the true outcome.

    Comments

    1. Log odds of predicted probability of survival = 1.735 - 0.121 (Age-50; if older than 50, otherwise zero) + 0.270 (GCS score) - 0.061 (ISS) + 1.26 (no haematoma on CT) - 0.512 (one reacting pupil) - 1.884 (if neither pupil reacting)

    Citation

    1. Signorini DF, Andrews PJ, Jones PA, et al: predicting survival using simple clinical variable: a case study in traumatic brain injury. Journal of Neurology, Neurosurgery and Psychiatry 1999; 66: 20-25
    Search Terms: ?
    Contributor: Chris Ball and Clare Wotton, November 1999
    Reviewer:

    Clinical Question.
    Patient severe head injury, traumatic brain injury
    Intervention or Exposure clinical features, CT scan
    Outcome death