Predictors and Time-Based Hospital Mortality in Patients with Isolated and Polytrauma Brain Injuries

Traumatic brain injury (TBI) is a major cause of morbidity and mortality worldwide. We studied the predictors and time-based mortality in patients with isolated and polytrauma brain injuries in a rapidly developing country. We hypothesized that TBI-related 30-day mortality is decreasing over time.

A retrospective analysis was conducted for all patients with moderate-to-severe TBI who were admitted directly to a level 1 trauma center between 2010 and 2014. Patient's data were analyzed and compared according to survival (survived vs. not survived), time (early death [2 days], intermediate [3-7 days] versus late [>7 days]) post-injury, and type (polytrauma vs. isolated TBI). Cox proportional hazards models were performed for the predictors of mortality.

A total of 810 patients were admitted with moderate-to-severe TBI with a median age of 27 years. Traffic-related injury was the main mechanism of TBI (65%). Isolated TBIs represented 22.6% of cases and 56% had head AIS >3. The overall mortality rate was 27%, and most of deaths occurred in the intermediate (40%) and early period (38%). The incidence of TBI was greater in patients aged 21-30 years but the mortality was proportionately higher among elderly. The average annual incidence was 8.43 per 100,000 population with an overall mortality of 2.28 per 100,000 population. Kaplan-Meier curves showed that polytrauma had greater mortality than isolated TBI. However, Cox survival analysis showed that age [Hazard ratio (HR) 1.02], scene GCS (HR 0.86),subarachnoid hemorrhage (HR 1.7), and blood transfusion amount (HR 1.03) were the predictors of mortality regardless of being polytrauma or isolated TBI after controlling for 14 relevant covariates.

The 30-day survival in patients with TBI is improving over the years in Qatar; however, the mortality remains high in the elderly males. The majority of deaths occurred within a week after the injury. Further studies are needed to assess the long-term survival in patients with moderate-to-severe TBI.