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Journal of Neurology, Neurosurgery, and Psychiatry logoLink to Journal of Neurology, Neurosurgery, and Psychiatry
. 1999 Jan;66(1):20–25. doi: 10.1136/jnnp.66.1.20

Predicting survival using simple clinical variables: a case study in traumatic brain injury

D Signorini 1, P Andrews 1, P Jones 1, J Wardlaw 1, J Miller 1
PMCID: PMC1736162  PMID: 9886445

Abstract

OBJECTIVES—Prediction of patient outcome can be useful as an aid to clinical decision making, to explore possible biological mechanisms, and as part of the clinical audit process. Many studies have constructed predictive models for survival after traumatic brain injury, but these have often used expensive, time consuming, or highly specialised measurements. The aim of this study was to develop a simple easy to use model involving only variables which are rapidly and easily clinically achievable in routine practice.
METHODS—All consecutive patients admitted to a regional trauma centre with moderate or severe head injury were enrolled in the study. Basic demographic, injury, and CT characteristics were recorded. Patient survival at 1 year was used to construct a simple predictive model which was then validated on a very similar patient group.
RESULTS—372 patients were included in the study, of whom 365 (98%) were followed up for survival at 1 year. Multiple logistic regression resulted in a model containing age (p<0.001), Glasgow coma scale score (p<0.001), injury severity score (p<0.001), pupil reactivity (p=0.004), and presence of haematoma on CT (p=0.004) as independently significant predictors of survival. The model was validated on an independent set of 520 patients, showing good discrimination and adequate calibration, but with a tendency to be pessimistic about very severely injured patients. It is presented as an easy to use nomogram.
CONCLUSIONS—All five variables have previously been shown to be related to survival. All variables in the model are clinically simple and easy to measure rapidly in a centre with access to 24 hour CT, resulting in a model that is both well validated and clinically useful.



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Selected References

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  1. Alexander E., Jr Global Spine and Head Injury Prevention Project (SHIP) Surg Neurol. 1992 Dec;38(6):478–479. doi: 10.1016/0090-3019(92)90124-6. [DOI] [PubMed] [Google Scholar]
  2. Baker S. P., O'Neill B., Haddon W., Jr, Long W. B. The injury severity score: a method for describing patients with multiple injuries and evaluating emergency care. J Trauma. 1974 Mar;14(3):187–196. [PubMed] [Google Scholar]
  3. Braitman L. E., Davidoff F. Predicting clinical states in individual patients. Ann Intern Med. 1996 Sep 1;125(5):406–412. doi: 10.7326/0003-4819-125-5-199609010-00008. [DOI] [PubMed] [Google Scholar]
  4. Brooks D. N., McKinlay W. Personality and behavioural change after severe blunt head injury--a relative's view. J Neurol Neurosurg Psychiatry. 1983 Apr;46(4):336–344. doi: 10.1136/jnnp.46.4.336. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Chesnut R. M., Marshall L. F., Klauber M. R., Blunt B. A., Baldwin N., Eisenberg H. M., Jane J. A., Marmarou A., Foulkes M. A. The role of secondary brain injury in determining outcome from severe head injury. J Trauma. 1993 Feb;34(2):216–222. doi: 10.1097/00005373-199302000-00006. [DOI] [PubMed] [Google Scholar]
  6. Choi S. C., Muizelaar J. P., Barnes T. Y., Marmarou A., Brooks D. M., Young H. F. Prediction tree for severely head-injured patients. J Neurosurg. 1991 Aug;75(2):251–255. doi: 10.3171/jns.1991.75.2.0251. [DOI] [PubMed] [Google Scholar]
  7. Choi S. C., Narayan R. K., Anderson R. L., Ward J. D. Enhanced specificity of prognosis in severe head injury. J Neurosurg. 1988 Sep;69(3):381–385. doi: 10.3171/jns.1988.69.3.0381. [DOI] [PubMed] [Google Scholar]
  8. Dybowski R., Weller P., Chang R., Gant V. Prediction of outcome in critically ill patients using artificial neural network synthesised by genetic algorithm. Lancet. 1996 Apr 27;347(9009):1146–1150. doi: 10.1016/s0140-6736(96)90609-1. [DOI] [PubMed] [Google Scholar]
  9. Feldman Z., Contant C. F., Robertson C. S., Narayan R. K., Grossman R. G. Evaluation of the Leeds prognostic score for severe head injury. Lancet. 1991 Jun 15;337(8755):1451–1453. doi: 10.1016/0140-6736(91)93137-x. [DOI] [PubMed] [Google Scholar]
  10. Gennarelli T. A., Champion H. R., Sacco W. J., Copes W. S., Alves W. M. Mortality of patients with head injury and extracranial injury treated in trauma centers. J Trauma. 1989 Sep;29(9):1193–1202. doi: 10.1097/00005373-198909000-00002. [DOI] [PubMed] [Google Scholar]
  11. Gennarelli T. A., Spielman G. M., Langfitt T. W., Gildenberg P. L., Harrington T., Jane J. A., Marshall L. F., Miller J. D., Pitts L. H. Influence of the type of intracranial lesion on outcome from severe head injury. J Neurosurg. 1982 Jan;56(1):26–32. doi: 10.3171/jns.1982.56.1.0026. [DOI] [PubMed] [Google Scholar]
  12. Gibson R. M., Stephenson G. C. Aggressive management of severe closed head trauma: time for reappraisal. Lancet. 1989 Aug 12;2(8659):369–371. doi: 10.1016/s0140-6736(89)90546-1. [DOI] [PubMed] [Google Scholar]
  13. Harrell F. E., Jr, Lee K. L., Mark D. B. Multivariable prognostic models: issues in developing models, evaluating assumptions and adequacy, and measuring and reducing errors. Stat Med. 1996 Feb 28;15(4):361–387. doi: 10.1002/(SICI)1097-0258(19960229)15:4<361::AID-SIM168>3.0.CO;2-4. [DOI] [PubMed] [Google Scholar]
  14. Heinzelmann M., Platz A., Imhof H. G. Outcome after acute extradural haematoma, influence of additional injuries and neurological complications in the ICU. Injury. 1996 Jun;27(5):345–349. doi: 10.1016/0020-1383(95)00223-5. [DOI] [PubMed] [Google Scholar]
  15. Jencks S. F., Daley J., Draper D., Thomas N., Lenhart G., Walker J. Interpreting hospital mortality data. The role of clinical risk adjustment. JAMA. 1988 Dec 23;260(24):3611–3616. [PubMed] [Google Scholar]
  16. Jennett B., Teasdale G., Braakman R., Minderhoud J., Heiden J., Kurze T. Prognosis of patients with severe head injury. Neurosurgery. 1979 Apr;4(4):283–289. doi: 10.1227/00006123-197904000-00001. [DOI] [PubMed] [Google Scholar]
  17. Jennett B., Teasdale G., Braakman R., Minderhoud J., Knill-Jones R. Predicting outcome in individual patients after severe head injury. Lancet. 1976 May 15;1(7968):1031–1034. doi: 10.1016/s0140-6736(76)92215-7. [DOI] [PubMed] [Google Scholar]
  18. Jennett B., Teasdale G., Galbraith S., Pickard J., Grant H., Braakman R., Avezaat C., Maas A., Minderhoud J., Vecht C. J. Severe head injuries in three countries. J Neurol Neurosurg Psychiatry. 1977 Mar;40(3):291–298. doi: 10.1136/jnnp.40.3.291. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Lemeshow S., Klar J., Teres D., Avrunin J. S., Gehlbach S. H., Rapoport J., Rué M. Mortality probability models for patients in the intensive care unit for 48 or 72 hours: a prospective, multicenter study. Crit Care Med. 1994 Sep;22(9):1351–1358. doi: 10.1097/00003246-199409000-00003. [DOI] [PubMed] [Google Scholar]
  20. Lemeshow S., Teres D., Klar J., Avrunin J. S., Gehlbach S. H., Rapoport J. Mortality Probability Models (MPM II) based on an international cohort of intensive care unit patients. JAMA. 1993 Nov 24;270(20):2478–2486. [PubMed] [Google Scholar]
  21. Nicoll J. A., Roberts G. W., Graham D. I. Amyloid beta-protein, APOE genotype and head injury. Ann N Y Acad Sci. 1996 Jan 17;777:271–275. doi: 10.1111/j.1749-6632.1996.tb34431.x. [DOI] [PubMed] [Google Scholar]
  22. Roberts G. W., Gentleman S. M., Lynch A., Murray L., Landon M., Graham D. I. Beta amyloid protein deposition in the brain after severe head injury: implications for the pathogenesis of Alzheimer's disease. J Neurol Neurosurg Psychiatry. 1994 Apr;57(4):419–425. doi: 10.1136/jnnp.57.4.419. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Ruff R. M., Marshall L. F., Crouch J., Klauber M. R., Levin H. S., Barth J., Kreutzer J., Blunt B. A., Foulkes M. A., Eisenberg H. M. Predictors of outcome following severe head trauma: follow-up data from the Traumatic Coma Data Bank. Brain Inj. 1993 Mar-Apr;7(2):101–111. doi: 10.3109/02699059309008164. [DOI] [PubMed] [Google Scholar]
  24. Stablein D. M., Miller J. D., Choi S. C., Becker D. P. Statistical methods for determining prognosis in severe head injury. Neurosurgery. 1980 Mar;6(3):243–248. [PubMed] [Google Scholar]
  25. Temkin N. R., Holubkov R., Machamer J. E., Winn H. R., Dikmen S. S. Classification and regression trees (CART) for prediction of function at 1 year following head trauma. J Neurosurg. 1995 May;82(5):764–771. doi: 10.3171/jns.1995.82.5.0764. [DOI] [PubMed] [Google Scholar]
  26. Williams J. M., Gomes F., Drudge O. W., Kessler M. Predicting outcome from closed head injury by early assessment of trauma severity. J Neurosurg. 1984 Sep;61(3):581–585. doi: 10.3171/jns.1984.61.3.0581. [DOI] [PubMed] [Google Scholar]

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