Prognostic significance of age in traumatic brain injury

BACKGROUND: Age is a strong prognostic factor following traumatic brain injury (TBI), with discrepancies defining the critical prognostic age threshold. This study was undertaken to determine the impact of various age thresholds on outcome after TBI. MATERIALS AND METHODS: The ages of patients admitted with TBI were prospectively studied in relation to mode of injury, Glasgow coma score (GCS), CT category and surgical intervention. Mortality was assessed at 1 month, and neurological outcome was assessed at 6 months. Appropriate statistical analyzes (details in article) were performed. RESULTS: Of the total 244 patients enrolled, 144 patients had severe, 38 patients had moderate and 62 patients had mild TBI, respectively. Age had significant association with grade of injury, CT category and surgical intervention (P < 0.01). Mortality at 1 month was significantly associated with increasing age with patients dead at 1 month being 15% for age < 18, 44% for age between 18 and 59 years, and 52% in the age group > 59 years respectively (P < 0.001). Unfavorable outcome showed significant association with an increase in age, every decade (P < 0.001). In multivariate analysis, there was stepwise increase in the odds of unfavorable outcome across age groups centered on 40 years, independent of confounding factors. The adjusted odds ratios for unfavorable outcome with regard to age thresholds 30, 40 and 50 years were 11.3, 53.3 and 1171, respectively (P < 0.005). Moreover, there was significant association of unfavorable outcome with age > 40 years in all subgroups, based on GCS and surgical intervention (P < 0.05). CONCLUSIONS: In patients with TBI, age demonstrates independent association with unfavorable outcome at 6 months, in stepwise manner centered on a threshold of 40 years.