To characterize the patterns of presentation of adults with head injury to the Emergency Department.
This is a cohort study that sought to collect injury and outcome variables with the goal of characterizing the very early natural history of traumatic brain injury in adults. This IRB-approved project was conducted in collaboration with our Institution’s Center for Translational Science Institute. Data were entered in REDCap, a secure database. Statistical analyses were performed using JMP 10.0 pro for Windows.
The cohort consisted of 2,394 adults, with 40% being women and 79% Caucasian. The most common mechanism was fall (47%) followed by motor vehicle collision (MVC) (36%). Patients sustaining an MVC were significantly younger than those whose head injury was secondary to a fall (P < 0.0001). Ninety-one percent had CT imaging; hemorrhage was significantly more likely with worse severity as measured by the Glasgow Coma Score (chi-square, P < 0.0001). Forty-four percent were admitted to the hospital, with half requiring ICU admission. In-hospital death was observed in 5.4%, while neurosurgical intervention was required in 8%. For all outcomes, worse TBI severity per GCS was significantly associated with worse outcomes (logistic regression, P < 0.0001, adjusted for age).
These cohort data highlight the burden of TBI in the Emergency Department and provide important demographic trends for further research.
- Traumatic Brain Injury
- Head Injury
- Motor Vehicle Collision
- Recreational Vehicle
- Common Data Element
Each year, on average, traumatic brain injuries (TBIs) are associated with an estimated 1.35 million emergency department visits, 275,000 hospitalizations, and 52,000 deaths in the US . This does not account for those who sustain a head injury and receive no care. TBI is a contributing factor to a third (30.5%) of all injury-related deaths in the US [1, 2]. Roughly three quarters of TBIs that occur each year are concussions or other forms of mild TBI . TBI is a significant burden to our health-care system. Direct medical costs and indirect costs such as lost productivity of TBI totaled an estimated $76.5 billion in the US in 2000 .
Traumatic brain injury is an important public health problem in the US. It is frequently referred to as the “silent epidemic” because the complications from TBI, such as changes affecting thinking, sensation, language, or emotions, may not be readily apparent. In addition, awareness about TBI among the general public is limited .
The CDC states: “population-based data on TBI are critical to understanding its impact on the American people. Knowing who is affected by TBIs and how they occur can help shape prevention strategies, priorities for research, and also support the need for services among individuals living with TBI” . This study was undertaken specifically to address this need on a local level. By understanding our population’s patterns of injury and outcomes, we would be able to design an optimal system not only to provide acute care, but also to design programs that address research and education needs. The objective of this study was to characterize the population of patients who sustain head injuries and present to our emergency department. The reason was to understand our local demographics in an effort to design processes and interventions that would mitigate the morbidity and mortality associated with this injury pattern.
This was a retrospective chart review that spanned a 30-month period from 1 January 2008 to 31 August 2010. Methodology and other study details are reported in accordance with STROBE guidelines .
The study was conducted in the Emergency Department (ED) of a level-one trauma center in the southeastern US. Our ED sees over 79,000 visits per year, and is home to both emergency medicine and general surgery residency training programs. This study was approved by our institution’s IRB as an expedited study with an HIPAA waiver.
Data were abstracted from the electronic medical record using an a priori designed data abstraction form. Persons entering the data were blinded to the study hypotheses and outcomes. Data were entered into our Clinical and Translational Science Institute’s REDCap database. REDCap (Research Electronic Data Capture) is a secure, Web-based application designed to support traditional case report form data capture. Statistical analyses were performed using JMP Pro10.0 for Windows. Normally distributed variables are summarized using means and standard deviations, while skewed variables are reported using medians and interquartile ranges (IQR). Missing data were recorded as unknown.
Corresponding TBI diagnosis
800.00 to 804.9
Fracture of skull
Cerebral laceration and contusion
Subarachnoid, subdural, and extradural hemorrhage after injury
Other unspecified intracranial hemorrhage after injury
Intracranial injury of other and unspecified nature
Other unspecified injury to head
Severity of head injury was classified using the Glasgow Coma Scale , with GCS 13–15 considered as mild, GCS 9–12 as moderate, and a score less than 9 classified as severe. Post-injury symptomatology collected included the occurrence of loss of consciousness (LOC), the duration of LOC, an alteration in consciousness (AOC), posttraumatic amnesia (PTA), seizure, and vomiting. An AOC was considered to be present if the patient reported any of the following: feeling dazed or confused, having difficulty thinking, or if the neurologic exam revealed a decreased mental status.
Data were also collected for mechanism of injury, including a fall, traffic accident, recreational activity, sports, and assault. Recreational activities included injuries related to bicycles, motorcycles, all-terrain vehicles (ATVs), other vehicles (e.g., scooters), watercraft, or other (horseback riding). Information about seatbelt use in people involved in traffic accidents and helmet use in people with recreational vehicle injuries was also collected.
Racial and gender composition of head injury (based on the 2010 census) in adult subjects
City of Gainesville
TBI in ED
Caucasian (Non-Hispanic White)
Black or African-American
Hispanic or Latino
Other Native American or Native Alaskan, Pacific Islander, two or more races, or some other race
The majority (88%) of the injuries occurred less than 12 h prior to presentation. Another 5% presented within 24 h. Seventy-five percent of the cohort was transported by EMS for their head injury (65.7% ground, 9.5% air). The remaining 25% presented to the ED by car, another vehicle, or walked-in. The majority (85.1%) had mild TBI (GCS 13–15); 3.1% were moderate (GCS 9–12), and 11.7% were severe (GCS 8 or below).
Loss of consciousness (LOC) was definitively reported by 51.3%, while in an additional 14.1% of subjects, it was unknown whether they lost consciousness or not. Among those with loss of consciousness, the duration of LOC was known for 59% (46.1% had LOC for 0–30 min, and 12.9% reported LOC of more than 30 min). Altered mental status was experienced by 28.9% of subjects, while 25.6% experienced post-traumatic amnesia for events before and/ or after the injury. Vomiting and seizure were less common symptoms after a TBI. In our population, 6.5% had at least one episode of vomiting after injury; 3.5% suffered from seizure after head trauma.
Mechanism of injury
The most common mechanism for head injury for our population was a fall (46.8%). This included falls from the ground level or from any height, including trees and roofs, collapse due to syncope, and also falls associated with assault or fall by any other reason.
The second most common mechanism was motor vehicle collision (MVC), at 35.5%. Most often the subject was in the driver’s seat (61.2%), followed by front passenger seat (13%). Out of those involved in an MVC, just 46% reported wearing the seatbelt. The MVC mechanism was significantly more common in severe compared to mild TBI (52% vs. 34%, P < 0.0001).
The percentages of head CT abnormalities
Abnormal CT finding
% of total abnormal CTs (n= 1,047)
% of total CTs (n= 2,201)
% of total population (n= 2,394)
Extracalvarial soft tissue swelling
Fracture of skull
Fracture of maxillofacial bones (except nose)
Fracture of nasal bones
Calvarial fracture through carotid canal
Calvarial fracture through foramen magnum
Upward transtentorial herniation
Downward transtentorial herniation
Parenchymal or hemorrhagic contusion
Diffuse axonal injury (unilateral/bilateral)
Percentages based on whole cohort, n = 2,394
Any CT abnormality as listed in table 3
Mild (n = 2,038)
Moderate (n = 75)
Severe (n = 280)
Hospital admission rates for TBI based on severity
ED TBI severity (GCS)
Admitted ( n,%)
ICU stay (n,%)
Intra-hospital death (n,%)
Discharge disposition according to TBI severity
ED TBI severity (GCS)
Skilled nursing facility
Left against medical advice
Death in hospital
The 72-h return to the ED and 30-day re-admission rates by severity
ED TBI severity (GCS)
Return to ED within 72 h ( n,%)
Re-admitted to the hospital within 30 days ( n,%)
Why the current study is important
Our findings characterize injury severity, etiology, symptomology, and outcome in patients with acute TBI presenting to a Trauma Level I teaching institution. International think tanks identified areas of focus for TBI research [11, 12]. A consistent underlying theme is the need to define epidemiology and basic hospital outcomes for local populations. The current cohort provides an epidemiologic account of TBI patients that will add to understanding the magnitude of TBI, drive research priorities, and identify clinical areas of need.
Our descriptive study is unique in several ways and adds to the literature a novel description of TBI patients. The current study represents one of the largest cohorts of mild TBI patients in the civilian population. Mild TBI (mTBI) accounts for 80–85% of all TBIs and as such represents a large proportion of disability from TBI . This improved understanding has led to more widespread recognition . Clinicians and legislators have recognized the consequences of mild TBI can be quite significant.
Review of other TBI cohort studies
There have been a few other cohorts describing TBI, but none have described the acute symptomatology with the level of detail that the current study does or in a population that has generalizability. Thus, a survey of soldiers deployed in Iraq  does report symptomology, but the cohort is not varied enough in mechanism, gender, and age to represent the general population, and it describes the symptoms experienced by the soldiers reported at a date much later than the injury, which inherently carries recall bias. A historical study from the Mayo Clinic reports on incidence morbidity and mortality outcomes after TBI for Olmsted county for the years 1935–1974, but could not comment on acute emergency department variables because of the design and time period . Similarly, a New Zealand study reports on the incidence and outcomes, but did not assess acute symptomatology or clinical variables . Two papers report on emergency department visits for TBI from 1992–94  and 1995–16 ; however, these studies are not only now 15–20 years old, but also rely on data collected from the National Hospital Ambulatory Medical Care Survey , in which hospital staff in selected US hospitals are instructed to complete patient record forms for a systematic random sample of patient visits during a randomly assigned 4-week reporting period. This survey has inherent limitations, including a modest response rate, optional participation without incentives, and inability to capture many patient level data including acute symptomatology. More recent cohorts have been described as well, but these have been limited to moderate and severe TBI [21, 22] or patients admitted to an ICU , both distinct from the cohort described in the current study.
Comparing outcomes between the current study and the other published studies
Among the moderate and severe TBIs, comparisons can be made to other studies even when emergency department acute symptomatology was not specifically studied, as these are a less heterogeneous group than mild TBI patients. For example, Andriessen et al.  prospectively enrolled 508 moderate and severe patients across five level I trauma centers in The Netherlands. Their rates of abnormal CTs were comparable to the current cohort (56 vs. 71% for moderate and 81 vs. 91% for severe) when accounting for extracalvarial soft tissue swelling. These studies also mirror neurosurgical intervention (26% vs. 25% for moderate and 29% vs. 34% for severe).
A study examining 476 moderate and 1,701 severe TBI patients across Europe and North America  reported MVC as the mechanism at a rate similar to that in the current report (57 vs. 52% of the TBIs in their severe cohort were due to an MVC mechanism).
Given the lack of other large cohort studies that focus on acute symptomatology in mild TBI, comparisons of our study findings within the mild TBI cohort to other such populations are not possible. We did note, for instance, that mild TBI had unexpected amounts of pathology on CT (21% had bleeds, 13% had fractures), neurosurgical intervention rates (3.8%), and death rates (0.8%). This higher than expected acuity in this group may indicate the GCS scale was an underestimation of illness or that the medical community’s assumptions about “mild” TBI may be underestimating the disease process.
While some of the explicit strengths of our study include the large number of patients with all severities of TBI (especially mild TBI) presenting to our ED and the ability to collect clinical information unavailable through billing coding, there are some inherent weaknesses in our methods as well. The limitations of the current study are: (1) the cohort was assembled using billing codes as a starting point; (2) data were abstracted from medical record review and therefore certain pieces of data were missing for some subjects; (3) these data pertain to a single medical center, although the sample appears to be representative of national demographics.
These cohort data highlight the burden of TBI in the Emergency Department and provide important demographic trends for further research. The higher than expected positivity as well as intervention rates of the mild TBI patients is a important finding that warrants further study.
- Zitnay GA, Zitnay KM, Povlishock JT, Hall ED, Marion DW, Trudel T, Zafonte RD, Zasler N, Nidiffer FD, DaVanzo J, Barth JT: Traumatic brain injury research priorities: the conemaugh international brain injury symposium. J Neurotrauma 2008,25(10):1135–1152. 10.1089/neu.2008.0599PubMedView ArticleGoogle Scholar
- National Center for Injury Prevention and Control: Report to Congress on Mild Traumatic Brain Injury in the United States: Steps to Prevent a Serious Public Health Problem. Atlanta, GA: Centers for Disease Control and Prevention; 2003.Google Scholar
- Roehr B: Traumatic brain injury is more widespread than previously estimated. BMJ 2012, 345: e8098. 10.1136/bmj.e8098PubMedView ArticleGoogle Scholar
- Hoge CW, McGurk D, Thomas JL, Cox AL, Engel CC, Castro CA: Mild traumatic brain injury in US soldiers returning from Iraq. N Engl J Med 2008,358(5):453–463. 10.1056/NEJMoa072972PubMedView ArticleGoogle Scholar
- Annegers JF, Grabow JD, Kurland LT: The incidence, causes, and secular trends of head trauma in Olmsted County, Minnesota, 1935–1974. Neurology 1980, 30: 912–919. 10.1212/WNL.30.9.912PubMedView ArticleGoogle Scholar
- Feigin VL, Theadom A, Barker-Collo S, Starkey NJ, McPherson K, Kahan M, Dowell A, Brown P, Parag V, Kydd R, Jones K, Jones A, Ameratunga S, BIONIC Study Group: Incidence of traumatic brain injury in New Zealand: a population-based study. Lancet Neurol 2013,12(1):28–29. 10.1016/S1474-4422(12)70294-6View ArticleGoogle Scholar
- Jager TE, Weiss HB, Coben JH: Traumatic brain injuries evaluated in US emergency departments, 1992–1994. Acad Emerg Med 2000, 7: 134–140. 10.1111/j.1553-2712.2000.tb00515.xPubMedView ArticleGoogle Scholar
- Guerrero JL, Thurman DJ, Sniezek JE: Emergency department visits associated with traumatic brain injury: United States, 1995–1996. Brain Inj 2000, 14: 181–186. 10.1080/026990500120835PubMedView ArticleGoogle Scholar
- The National Ambulatory Medical Care Survey. . Accessed February 22, 2013 www.cdc.gov/nchs/nhamcs.htm
- Hukkelhoven CW, Steyerberg EW, Frarace E, Habbema JD, Marshall LF: Maas AI Regional Differences in patient characteristics, case management, and outcomes in traumatic brain injury: experience from the tirilazad trials. J Neurosurg 2002, 97: 549–557. 10.3171/jns.2002.97.3.0549PubMedView ArticleGoogle Scholar
- Andriessen TMC, Horn J, Franschman G, van der Naalt J, Haitsma I, Jacobs B, Steyerberg EW, Vos PE: Epidemiology, severity classification, and outcome of moderate and severe traumatic brain injury: a prospective multicenter study. J of Neuro trauma 2011, 28: 2019–2031.Google Scholar
- Myburgh JA, Cooper DJ, Finder SR, Venkatesh B, Jones D, Higgins A, Bishop N, Higlett T: Epidemiology and 12-month outcomes from traumatic brain injury in Australia and New Zealand. J Trauma 2008, 64: 854–862. 10.1097/TA.0b013e3180340e77PubMedView ArticleGoogle Scholar