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Changes in the demographics, approach, and treatment of traumatic brain injury (TBI) patients require regular evaluation of epidemiological profiles, injury severity classification, and outcomes. This prospective multicenter study provides detailed information on TBI-related variables of 508 moderate-to-severe TBI patients. Variability in epidemiology and outcome is examined by comparing our cohort with previous multicenter studies. Additionally, the relation between outcome and injury severity classification assessed at different time points is studied. Based on the emergency department Glasgow Coma Scale (GCS), 339 patients were classified as having severe and 129 as having moderate TBI. In 15%, the diagnosis differed when the accident scene GCS was used for classification. In-hospital mortality was higher if severe TBI was diagnosed at both time points (44%) compared to moderate TBI at one or both time points (7-15%, p<0.001). Furthermore, 14% changed diagnosis when a threshold (≥6 h) for impaired consciousness was used as a criterion for severe TBI: In-hospital mortality was<5% when impaired consciousness lasted for<6 h. This suggests that combining multiple clinical assessments and using a threshold for impaired consciousness may improve the classification of injury severity and prediction of outcome. Compared to earlier multicenter studies, our cohort demonstrates a different case mix that includes a higher age (mean=47.3 years), more diffuse (Traumatic Coma Databank [TCDB] I-II) injuries (58%), and more major extracranial injuries (40%), with relatively high 6 month mortality rates for both severe (46%) and moderate (21%) TBI. Our results confirm that TBI epidemiology and injury patterns have changed in recent years whereas case fatality rates remain high.

IntroductionThe relationship between isolated traumatic brain injury (TBI) associated coagulopathy and patient prognosis frequently lacks information regarding the time course of coagulation disorders throughout the post-traumatic period. This study was conducted to assess the prevalence and time course of post-traumatic coagulopathy in patients with isolated TBI and the relationship of these hemostatic disorders with outcome.MethodsThe local Human Subjects Committee approved the study. We retrospectively studied the medical records of computed tomography (CT)-confirmed isolated TBI patients with an extracranial abbreviated injury scale (AIS) <3 who were primarily referred to a Level 1 trauma centre in Amsterdam (n = 107). Hemostatic parameters including activated partial thromboplastin time (aPTT), prothrombin time (PT), platelet count, hemoglobin, hematocrit, glucose, pH and lactate levels were recorded throughout a 72-hour period as part of a routine standardized follow-up of TBI. Coagulopathy was defined as a aPPT >40 seconds and/or a PTT in International Normalized Ratio (INR) >1.2 and/or a platelet count <120*109/l.ResultsPatients were mostly male, aged 48 ± 20 years with a median injury severity score of 25 (range 20 to 25). Early coagulopathy as diagnosed in the emergency department (ED) occurred in 24% of all patients. The occurrence of TBI-related coagulopathy increased to 54% in the first 24 hours post-trauma. In addition to an increased age and disturbed pupillary reflex, both coagulopathy upon ED arrival and during the first 24 hours post-trauma provided an independent prognostic factor for unfavorable outcome (odds ratio (OR) 3.75 (95% CI 1.07 to 12.51; P = 0.04) and OR 11.61 (2.79 to 48.34); P = 0.003).ConclusionsOur study confirms a high prevalence of early and delayed coagulopathy in patients with isolated TBI, which is strongly associated with an unfavorable outcome. These data support close monitoring of hemostasis after TBI and indicate that correction of coagulation disturbances might need to be considered.

Guideline noncompliance was most prominent in patients with minor or very large computed tomography abnormalities. Intracranial pressure monitoring was not associated with 6-month outcome, but multiple baseline differences between monitored and nonmonitored patients underline the complex nature of examining the effect of intracranial pressure monitoring in observational studies.

IntroductionObservational studies of interventions are at risk for confounding by indication. The objective of the current study was to define the circumstances for the validity of methods to adjust for confounding by indication in observational studies.Patients and methodsWe performed post hoc analyses of data prospectively collected from three European and North American traumatic brain injury studies including 1,725 patients. The effects of three interventions (intracranial pressure [ICP] monitoring, intracranial operation and primary referral) were estimated in a proportional odds regression model with the Glasgow Outcome Scale as ordinal outcome variable. Three analytical methods were compared: classical covariate adjustment, propensity score matching and instrumental variable (IV) analysis in which the percentage exposed to an intervention in each hospital was added as an independent variable, together with a random intercept for each hospital. In addition, a simulation study was performed in which the effect of a hypothetical beneficial intervention (OR 1.65) was simulated for scenarios with and without unmeasured confounders.ResultsFor all three interventions, covariate adjustment and propensity score matching resulted in negative estimates of the treatment effect (OR ranging from 0.80 to 0.92), whereas the IV approach indicated that both ICP monitoring and intracranial operation might be beneficial (OR per 10% change 1.17, 95% CI 1.01–1.42 and 1.42, 95% CI 0.95–1.97). In our simulation study, we found that covariate adjustment and propensity score matching resulted in an invalid estimate of the treatment effect in case of unmeasured confounders (OR ranging from 0.90 to 1.03). The IV approach provided an estimate in the similar direction as the simulated effect (OR per 10% change 1.04–1.05) but was statistically inefficient.ConclusionThe effect estimation of interventions in observational studies strongly depends on the analytical method used. When unobserved confounding and practice variation are expected in observational multicenter studies, IV analysis should be considered.

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Prehospital management of TBI remains challenging. There are no universal objectives suitable to all patients. Randomized, controlled clinical trials are necessary for developing optimal protocols for paramedic and physician emergency medical teams.

Outcome prediction in moderate and severe TBI might be improved using the models that were designed in this study. However, conventional demographic, clinical and CT variables proved insufficient to predict disability in surviving patients. The information that can be derived from our prediction rules is important for the selection and stratification of patients recruited into clinical TBI trials.