Effect of demographic and injury etiologic factors on intensive care unit mortality after severe head injury in a low middle income country

Background: Low- and middle-income countries bear the mortality burden of head injury compared with high-income countries. Not much has been studied about predictors of poor outcome after head injury in these countries. This study describes and quantifies the effect of demographics and injury causative factors on mortality in a cohort managed in a Nigerian tertiary hospital intensive care. Materials and Methods: A retrospective study was undertaken of all patients admitted into intensive care with severe head injury at the University of Port Harcourt Teaching Hospital, Nigeria between 1st January, 1997 and 31st December, 2006. Logistic regression analysis was performed to examine the effect of age, gender and injury etiology on risk of intensive care unit (ICU) mortality. Results: The number of ICU admission for severe head injury was 231 patients with a male to female ratio of 2.8:1. Patients mean age and standard deviation was 31.2 +/- 15.5 years. The mortality rate was 52.8%. Road traffic injury was the most common etiologic factor (84%). Logistic regression analysis indicated a 56% increase in the risk of ICU mortality between the ages of 21 and 40 years. The effect of age was found to be nonlinear (likelihood ratio P = 0.033). On multivariable analysis, patients gender (odds ratio 1.07; 95% confidence interval: 0.56-1.97) and etiology of injury were not significantly associated with risk of mortality. Gender was not a modifier of the effect of age (P = 0.218). Conclusion: The study indicated a strong prognostic effect of age. Gender and etiology of injury had no effect on ICU mortality among study cohort.