Association between the American Board of Emergency Medicine Oral Certifying Examination and Future State Medical Board Disciplinary Actions.

Objectives: The American Board of Emergency Medicine (ABEM) requires a written examination (the Qualifying Examination) followed by the Oral Certifying Examination (OCE) to obtain ABEM certification. Maintaining ABEM certification is associated with fewer state medical board (SMB) disciplinary actions. We sought to determine the association between poor initial performance on the OCE and subsequent severe SMB disciplinary action. Methods: We included physicians who completed US categorical emergency medicine residencies in 2016 and earlier. We classified OCE performance as good (passed on first attempt) and poor (never passed or required > 1 attempt to pass). We obtained data on physician SMB disciplinary actions from the National Practitioner Data Bank that were limited to actions that denied licensure or altered the status of a medical license (eg, suspension). We determined the association between poor OCE performance and subsequent severe SMB disciplinary action. Results: Of 34,871, 93.5% passed the OCE on the first attempt, 6.1% required multiple attempts, and 0.3% never passed. Of the physicians (93.5%) with good OCE performance, 1.0% received a severe SMB action. Among physicians with poor OCE performance, 2.3% received a severe action; and of those who never passed, 1.7% received a severe action (Table 1). Poor OCE performance was associated with an increased odds of severe SMB disciplinary action (OR 2.21, 95% CI: 1.57-3.12). Conclusion: Physicians with poor OCE performance exhibited higher odds of experiencing a subsequent severe SMB disciplinary action. The OCE may have utility as a predictor of future professionalism or clinical performance.

EMS Treatment Guidelines in Major Traumatic Brain Injury With Positive Pressure Ventilation.

Importance: The Excellence in Prehospital Injury Care (EPIC) study demonstrated improved survival in patients with severe traumatic brain injury (TBI) following implementation of the prehospital treatment guidelines. The impact of implementing these guidelines in the subgroup of patients who received positive pressure ventilation (PPV) is unknown. Objective: To evaluate the association of implementation of prehospital TBI evidence-based guidelines with survival among patients with prehospital PPV. Design, Setting, and Participants: The EPIC study was a multisystem, intention-to-treat study using a before/after controlled design. Evidence-based guidelines were implemented by emergency medical service agencies across Arizona. This subanalysis was planned a priori and included participants who received prehospital PPV. Outcomes were compared between the preimplementation and postimplementation cohorts using logistic regression, stratified by predetermined TBI severity categories (moderate, severe, or critical). Data were collected from January 2007 to June 2017, and data were analyzed from January to February 2023. Exposure: Implementation of the evidence-based guidelines for the prehospital care of patient with TBI. Main Outcomes and Measures: The primary outcome was survival to hospital discharge, and the secondary outcome was survival to admission. Results: Among the 21 852 participants in the main study, 5022 received prehospital PPV (preimplementation, 3531 participants; postimplementation, 1491 participants). Of 5022 included participants, 3720 (74.1%) were male, and the median (IQR) age was 36 (22-54) years. Across all severities combined, survival to admission improved (adjusted odds ratio [aOR], 1.59; 95% CI, 1.28-1.97), while survival to discharge did not (aOR, 0.94; 95% CI, 0.78-1.13). Within the cohort with severe TBI but not in the moderate or critical subgroups, survival to hospital admission increased (aOR, 6.44; 95% CI, 2.39-22.00), as did survival to discharge (aOR, 3.52; 95% CI, 1.96-6.34). Conclusions and Relevance: Among patients with severe TBI who received active airway interventions in the field, guideline implementation was independently associated with improved survival to hospital admission and discharge. This was true whether they received basic airway interventions or advanced airways. These findings support the current guideline recommendations for aggressive prevention/correction of hypoxia and hyperventilation in patients with severe TBI, regardless of which airway type is used.

Emergency medicine physician workforce attrition differences by age and gender.

BACKGROUND: Emergency care workforce concerns have gained national prominence given recent data suggesting higher than previously estimated attrition. With little known regarding characteristics of physicians leaving the workforce, we sought to investigate the age and number of years since residency graduation at which male and female emergency physicians (EPs) exhibited workforce attrition. METHODS: We performed a repeated cross-sectional analysis of EPs reimbursed by Medicare linked to date of birth and residency graduation date data from the American Board of Emergency Medicine for the years 2013-2020. Stratified by gender, our primary outcomes were the median age and number of years since residency graduation at the time of attrition, defined as the last year during the study time frame that an EP provided clinical services. We constructed a multivariate logistic regression model to examine the association between gender and EP workforce attrition. RESULTS: A total of 25,839 (70.2%) male and 10,954 (29.8%) female EPs were included. During the study years, 5905 male EPs exhibited attrition at a median (interquartile range [IQR]) age of 56.4 (44.5-65.4) years, and 2463 female EPs exhibited attrition at a median (IQR) age of 44.0 (38.0-53.9) years. Female gender (adjusted odds ratio 2.30, 95% confidence interval 1.82-2.91) was significantly associated with attrition from the workforce. Male and female EPs had respective median (IQR) post-residency graduation times in the workforce of 17.5 (9.5-25.5) years and 10.5 (5.5-18.5) years among those who exhibited attrition and one in 13 males and one in 10 females exited clinical practice within 5 years of residency graduation. CONCLUSIONS: Female physicians exhibited attrition from the EM workforce at an age approximately 12 years younger than male physicians. These data identify widespread disparities regarding EM workforce attrition that are critical to address to ensure stability, longevity, and diversity in the EP workforce.

Correlation between prehospital and in-hospital hypotension and outcomes after traumatic brain injury.

BACKGROUND AND OBJECTIVE: Hypotension has a powerful effect on patient outcome after traumatic brain injury (TBI). The relative impact of hypotension occurring in the field versus during early hospital resuscitation is unknown. We evaluated the association between hypotension and mortality and non-mortality outcomes in four cohorts defined by where the hypotension occurred [neither prehospital nor hospital, prehospital only, hospital only, both prehospital and hospital]. METHODS: Subjects ≥10 years with major TBI were included. Standard statistics were used for unadjusted analyses. We used logistic regression, controlling for significant confounders, to determine the adjusted odds (aOR) for outcomes in each of the three cohorts. RESULTS: Included were 12,582 subjects (69.8% male; median age 44 (IQR 26-61). Mortality by hypotension status: No hypotension: 9.2% (95%CI: 8.7-9.8%); EMS hypotension only: 27.8% (24.6-31.2%); hospital hypotension only: 45.6% (39.1-52.1%); combined EMS/hospital hypotension 57.6% (50.0-65.0%); (p < 0.0001). The aOR for death reflected the same progression: 1.0 (reference-no hypotension), 1.8 (1.39-2.33), 2.61 (1.73-3.94), and 4.36 (2.78-6.84), respectively. The proportion of subjects having hospital hypotension was 19.0% (16.5-21.7%) in those with EMS hypotension compared to 2.0% (1.8-2.3%) for those without (p < 0.0001). Additionally, the proportion of patients with TC hypotension was increased even with EMS "near hypotension" up to an SBP of 120 mmHg [(aOR 3.78 (2.97, 4.82)]. CONCLUSION: While patients with hypotension in the field or on arrival at the trauma center had markedly increased risk of death compared to those with no hypotension, those with prehospital hypotension that was not resolved before hospital arrival had, by far, the highest odds of death. Furthermore, TBI patients who had prehospital hypotension were five times more likely to arrive hypotensive at the trauma center than those who did not. Finally, even "near-hypotension" in the field was strongly and independently associated the risk of a hypotensive hospital arrival (<90 mmHg). These findings are supportive of the prehospital guidelines that recommend aggressive prevention and treatment of hypotension in major TBI.

What are the Data for Current Prognostic Tools Used to Determine the Risk of Short-Term Adverse Events in Patients with Acute Heart Failure?

BACKGROUND: Acute heart failure (AHF) is a common condition evaluated in the emergency department (ED). Patients may present with a wide range of signs and symptoms, comorbidities, exacerbating factors, and ability to follow-up. Having a decision tool to objectively assess the risk of near-term events would help guide disposition decisions in these patients. CLINICAL QUESTION: What are the data for current tools used to determine the short-term risk of adverse events of patients with AHF in the ED setting? EVIDENCE REVIEW: Studies retrieved included six prospective studies and three retrospective cohort studies that evaluated the following five different risk scores that may predict the risk of serious adverse events in those with AHF: Ottawa Heart Failure Risk Score (OHFRS), Emergency Heart Failure Mortality Risk Grade (EHMRG), EHMRG at 30 days with addition of an ST depression variable (EHMRG30-ST), Multiple Estimation of Risk Based on the Emergency Department Spanish 40 Score in Patients with AHF Score (MEESSI-AHF), and the Improving Heart Failure Risk Stratification in the ED (STRATIFY) tool. CONCLUSIONS: Based on the available literature, risk scores, including the OHFRS; EHMRG; EHMRG30-ST; MEESSI-AHF; and STRATIFY, can help identify short-term risk of adverse events, but are insufficient in isolation. Clinicians should use these tools in conjunction with other factors, such as the patient's symptom trajectory, hemodynamics, and access to follow-up care.

What is the Best Agent for Rate Control of Atrial Fibrillation With Rapid Ventricular Response?

BACKGROUND: Atrial fibrillation (AF) is a common dysrhythmia associated with significant morbidity and mortality. Although many patients have stable AF, some patients can present with a rapid ventricular response (RVR). In these patients, it is important to lower their heart rate. However, there are several options available for rate control in the emergency department setting. CLINICAL QUESTION: What is the most effective agent for rate control for the patient with AF in RVR? EVIDENCE REVIEW: Studies retrieved included two prospective, randomized, double-blind studies and six retrospective cohort studies. These studies provide estimates of the efficacy and safety of calcium channel blockers and ß-blockers for rate control in those with AF with RVR. CONCLUSION: Based upon the available literature, diltiazem likely achieves rate control faster than metoprolol, though both agents seem safe and effective. Clinicians must consider the individual patient, clinical situation, and comorbidities when selecting a medication for rate control.

Do All Adult Psychiatric Patients Need Routine Laboratory Evaluation and an Electrocardiogram?

BACKGROUND: Acute psychiatric presentations account for a significant number of emergency department (ED) visits. These patients require assessment by the emergency physician and often need further evaluation by a psychiatrist, who may request routine laboratory evaluation and an electrocardiogram (ECG). CLINICAL QUESTION: Do all adult psychiatric patients need routine laboratory evaluation and an ECG? EVIDENCE REVIEW: Studies retrieved included 2 prospective, observational studies and 7 retrospective studies. These studies evaluate the utility of laboratory analysis in all patients presenting a psychiatric complaint and its impact on patient management and disposition. CONCLUSION: Based upon the available literature, routine laboratory analysis and ECG for all patients presenting with a psychiatric complaint are not recommended. Clinicians should consider the individual patient, clinical situation, and comorbidities when deciding to obtain further studies such as laboratory analysis. © 2022 Elsevier Inc.

Can I Send This Patient With Atrial Fibrillation Home From the Emergency Department?

BACKGROUND: Atrial fibrillation (AF) is one of the most common dysrhythmias managed in the emergency department (ED) setting. Due to the variety of patient presentations and disease severity, most patients in the United States are admitted to the hospital. CLINICAL QUESTION: In patients who present with AF, is there a reliable decision tool that clinicians can use to predict the risk of adverse outcome and determine who may be appropriate for discharge? EVIDENCE REVIEW: Studies retrieved included two prospective observational cohort studies and four retrospective observational studies. These studies evaluate the use of risk decision tools in predicting adverse outcomes in patients with AF. CONCLUSION: Based on the available literature, RED-AF, AFFORD, and the AFTER (complex, modified, and pragmatic) scores demonstrate modest predictive discrimination in predicting adverse events, but further validation is recommended.

American Board of Emergency Medicine Report on Residency and Fellowship Training Information (2021-2022).

The American Board of Emergency Medicine gathers extensive background information on the Accreditation Council of Graduate Medical Education-accredited emergency medicine residency and fellowship programs, as well as the residents and fellows training in those programs. We present the 2022 annual report on the status of physicians training in Accreditation Council of Graduate Medical Education-accredited emergency medicine training programs in the United States.

Fear Not: Utilizing Simulation for Medical Malpractice Education.

INTRODUCTION: Medical malpractice payouts across specialties totaled over $4.03 billion USD in 2019. It is estimated that over 72% of Emergency Medicine (EM) physicians will be involved in a medical malpractice lawsuit by age 55. The majority of EM residencies do not include adequate education on medicolegal risk mitigation and litigation. The purpose of the study is implementation of an innovative interprofessional simulation to target this education gap. METHODS: An anonymous pre- and post-survey was distributed to participating EM providers electronically. The surveys evaluated baseline medicolegal knowledge, self-rated deposition comfort and concern regarding malpractice litigation. The simulation event involved an interactive lecture on basic tenets of medical malpractice and state legal statutes from medicolegal experts. Resident physician volunteers acted as defendant physicians during simulated depositions using a redacted, closed malpractice case. RESULTS: Eighty EM providers attended the event over two days. All attendees completed the pre-survey (80/80), and 66.3% (53/80) completed the post-survey. The majority incorrectly answered 4 of 5 medicolegal questions. The mean comfort level regarding being deposed is 1.53 ± 0.94 on a 1-5 Likert scale (extremely uncomfortable to extremely comfortable); the mean level of concern/fear of malpractice litigation is 3.38 ± 0.95 on a 1-5 Likert scale (not at all to extremely concerned). There was a statistically significant increase in deposition comfort level post-event (1.83, P < .01). CONCLUSION: The majority of EM physicians are inexperienced and concerned regarding litigation. After participating in an educational event and observing a simulated deposition, physicians reported an increased comfort level regarding being deposed in the future.

Optimal Out-of-Hospital Blood Pressure in Major Traumatic Brain Injury: A Challenge to the Current Understanding of Hypotension.

STUDY OBJECTIVE: Little is known about the out-of-hospital blood pressure ranges associated with optimal outcomes in traumatic brain injuries (TBI). Our objective was to evaluate the associations between out-of-hospital systolic blood pressure (SBP) and multiple hospital outcomes without assuming any predefined thresholds for hypotension, normotension, or hypertension. METHODS: This was a preplanned secondary analysis from the Excellence in Prehospital Injury Care (EPIC) TBI study. Among patients (age ≥10 years) with major TBIs (Barell Matrix type 1 and/or Abbreviated Injury Scale-head severity ≥3) and lowest out-of-hospital SBPs of 40 to 299 mmHg, we utilized generalized additive models to summarize the distributions of various outcomes as smoothed functions of SBP, adjusting for important and significant confounders. The subjects who were enrolled in the study phase after the out-of-hospital TBI guideline implementation were used to validate the models developed from the preimplementation cohort. RESULTS: Among 12,169 included cases, the mortality model revealed 3 distinct ranges: (1) a monotonically decreasing relationship between SBP and the adjusted probability of death from 40 to 130 mmHg, (2) lowest adjusted mortality from 130 to 180 mmHg, and (3) rapidly increasing mortality above 180 mmHg. A subanalysis of the cohorts with isolated TBIs and multisystem injuries with TBIs revealed SBP mortality patterns that were similar to each other and to that of the main analysis. While the specific SBP ranges varied somewhat for the nonmortality outcomes (hospital length of stay, ICU length of stay, discharge to skilled nursing/inpatient rehabilitation, and hospital charges), the patterns were very similar to that of mortality. In each model, validation was confirmed utilizing the postimplementation cohort. CONCLUSION: Optimal adjusted mortality was associated with a surprisingly high SBP range (130 to 180 mmHg). Below this level, there was no point or range of inflection that would indicate a physiologically meaningful threshold for defining hypotension. Nonmortality outcomes showed very similar patterns. These findings highlight how sensitive the injured brain is to compromised perfusion at SBP levels that, heretofore, have been considered adequate or even normal. While the study design does did not allow us to conclude that the currently recommended treatment threshold (<90 mmHg) should be increased, the findings imply that the definition of hypotension in the setting of TBI is too low. Randomized trials evaluating treatment levels significantly higher than 90 mmHg are needed.

Can I Send This Syncope Patient Home From the Emergency Department?

BACKGROUND: Syncope is a common presentation to the emergency department (ED). A significant minority of these patients have potentially life-threatening pathology. Reliably identifying that patients require hospital admission for further workup and intervention is imperative. CLINICAL QUESTION: In patients who present with syncope, is there a reliable decision tool that clinicians can use to predict the risk of adverse outcome and determine who may be appropriate for discharge? EVIDENCE REVIEW: Four articles were reviewed. The first retrospective study found no difference in mortality or adverse events in patients admitted for further evaluation rather than discharged home with primary care follow-up. The next two articles examined the derivation and validation of the Canadian Syncope Risk Score (CSRS). After validation with an admission threshold score of -1, the sensitivity and specificity of the CSRS was 97.8% (95% confidence interval [CI] 93.8-99.6%) and 44.3% (95% CI 42.7-45.9%), respectively. The last article looked at the derivation of the FAINT score, a recently developed score to risk stratify syncope patients. A FAINT score of ≥ 1 (any score 1 or higher should be admitted) had a sensitivity of 96.7% (95% CI 92.9-98.8%) and specificity 22.2% (95% CI 20.7-23.8%). CONCLUSIONS: Syncope remains a difficult chief symptom to disposition from the ED. The CSRS is modestly effective at establishing a low probability of actionable disease or need for intervention. However, CSRS might not reduce unnecessary hospitalizations. The FAINT score has yet to undergo validation; however, the initial derivation study offers less diagnostic accuracy compared with the CSRS.

Can D-Dimer in Low-Risk Patients Exclude Aortic Dissection in the Emergency Department?

BACKGROUND: Aortic dissection (AD) is a challenging diagnosis associated with severe mortality. However, acute AD is a rare clinical entity and can be overevaluated in the emergency department. D-dimer, both alone and in combination with the Aortic Dissection Detection Risk Score (ADD-RS), has been studied as a tool to evaluate for AD. CLINICAL QUESTION: Can a negative D-dimer in low-risk patients exclude AD in the emergency department? EVIDENCE REVIEW: Retrieved studies included three systematic review and meta-analyses and two prospective cohort studies. D-dimer was found to be highly sensitive for acute AD, with a sensitivity of 98.0%. The ADD-RS was also highly sensitive (95.7%) for AD. Two meta-analyses reported a combination of a negative D-dimer and ADD-RS < 1 to have a pooled sensitivity of 99.9% and 100% for acute aortic syndrome. CONCLUSIONS: Neither D-dimer nor the ADD-RS alone provides adequate sensitivity to exclude acute AD. However, a negative D-dimer combined with an ADD-RS < 1 is likely sufficient to rule out AD. Even with these findings, physicians must place clinical judgment above laboratory testing or scoring systems when deciding whether to pursue a diagnosis of acute AD.

Is a Lumbar Puncture Required to Rule Out Atraumatic Subarachnoid Hemorrhage in Emergency Department Patients With Headache and Normal Brain Computed Tomography More Than Six Hours After Symptom Onset?

BACKGROUND: Atraumatic subarachnoid hemorrhage (SAH) is a deadly condition that most commonly presents as acute, severe headache. Controversy exists concerning evaluation of SAH based on the time from onset of symptoms, specifically if the headache occurred > 6 h prior to patient presentation. CLINICAL QUESTION: Do patients undergoing evaluation for atraumatic SAH who have a negative computed tomography (CT) scan of the head obtained more than 6 h after symptom onset require a subsequent lumbar puncture to rule out the diagnosis? EVIDENCE REVIEW: Studies retrieved included a retrospective cohort study, two prospective cohort studies, and a case-control study. These studies provide estimates of the diagnostic accuracy of head CT imaging obtained > 6 h from symptom onset and diagnostic test characteristics of subsequent lumbar puncture. CONCLUSION: The probability of SAH above which emergency clinicians should perform a lumbar puncture is 1.0%. This threshold is essentially the same as the estimated probability of SAH in patients with a negative head CT obtained more than 6 h from symptom onset. Emergency physicians might reasonably decide to either perform or forego this procedure. Consequently, we contend that the decision whether to perform lumbar puncture in these instances is an excellent candidate for shared decision-making.

Effect of Implementing the Out-of-Hospital Traumatic Brain Injury Treatment Guidelines: The Excellence in Prehospital Injury Care for Children Study (EPIC4Kids).

STUDY OBJECTIVE: We evaluate the effect of implementing the out-of-hospital pediatric traumatic brain injury guidelines on outcomes in children with major traumatic brain injury. METHODS: The Excellence in Prehospital Injury Care for Children study is the preplanned secondary analysis of the Excellence in Prehospital Injury Care study, a multisystem, intention-to-treat study using a before-after controlled design. This subanalysis included children younger than 18 years who were transported to Level I trauma centers by participating out-of-hospital agencies between January 1, 2007, and June 30, 2015, throughout Arizona. The primary and secondary outcomes were survival to hospital discharge or admission for children with major traumatic brain injury and in 3 subgroups, defined a priori as those with moderate, severe, and critical traumatic brain injury. Outcomes in the preimplementation and postimplementation cohorts were compared with logistic regression, adjusting for risk factors and confounders. RESULTS: There were 2,801 subjects, 2,041 in preimplementation and 760 in postimplementation. The primary analysis (postimplementation versus preimplementation) yielded an adjusted odds ratio of 1.16 (95% confidence interval 0.70 to 1.92) for survival to hospital discharge and 2.41 (95% confidence interval 1.17 to 5.21) for survival to hospital admission. In the severe traumatic brain injury cohort (Regional Severity Score-Head 3 or 4), but not the moderate or critical subgroups, survival to discharge significantly improved after guideline implementation (adjusted odds ratio = 8.42; 95% confidence interval 1.01 to 100+). The improvement in survival to discharge among patients with severe traumatic brain injury who received positive-pressure ventilation did not reach significance (adjusted odds ratio = 9.13; 95% confidence interval 0.79 to 100+). CONCLUSION: Implementation of the pediatric out-of-hospital traumatic brain injury guidelines was not associated with improved survival when the entire spectrum of severity was analyzed as a whole (moderate, severe, and critical). However, both adjusted survival to hospital admission and discharge improved in children with severe traumatic brain injury, indicating a potential severity-based interventional opportunity for guideline effectiveness. These findings support the widespread implementation of the out-of-hospital pediatric traumatic brain injury guidelines.

American Board of Emergency Medicine Report on Residency and Fellowship Training Information (2019-2020).

The American Board of Emergency Medicine gathers extensive background information on Accreditation Council for Graduate Medical Education (ACGME)-accredited emergency medicine residency and fellowship programs, as well as the residents and fellows training in those programs. We present the 2020 annual report on the status of physicians training in ACGME-accredited emergency medicine training programs in the United States.

Development of a Medical Student Cardiopulmonary Resuscitation Elective to Promote Education and Community Outreach.

INTRODUCTION:  One of the barriers to improving cardiac arrest survival is the low rate of cardiopulmonary resuscitation (CPR) provision. Identifying this as a public health issue, many medical students often assist in training the community in CPR. However, these experiences are often short and are not associated with structured resuscitation education, limiting the student's and the community's learning. In this assessment, we identified a need and developed a curriculum, including defined goals and objectives, for an undergraduate medical education (UME) elective in CPR. METHODS:  At an academic university environment with a strong UME program, we developed a longitudinal UME elective in CPR. The curriculum is a four-year longitudinal experience, which satisfies two weeks of their fourth year of medical school. The curriculum includes structured training over the four-year period in the fundamentals of resuscitation science (through didactics, journal club, and hands-on skills training), in addition to structured community CPR teaching. The elective concludes with a final hands-on summative appraisal. Data concerning medical student program enrollment, CPR training events conducted, venues of events, and the number of individuals trained were collected over a five-year period. RESULTS:  The CPR elective was developed with clear goals and objectives based on identified needs. Over the five-year period, 186 medical students completed the CPR longitudinal elective, accounting for 8.4% of the total medical student population. Students completed curriculum requirements and satisfied both didactic and hands-on training with all students passing the final summative appraisal. Over the five-year period, students trained 8,694 people in bystander CPR. The summative evaluation had a 100% pass rate. CONCLUSION:  Implementation of a longitudinal CPR elective improved resuscitation science education for medical students and fostered increased community CPR training. This describes one local effort to improve resuscitation science education and training for medical students. Further work will need to be done to evaluate the impact of UME resuscitation curricula on medical student career choice and resuscitation outcomes.

Association of Statewide Implementation of the Prehospital Traumatic Brain Injury Treatment Guidelines With Patient Survival Following Traumatic Brain Injury: The Excellence in Prehospital Injury Care (EPIC) Study.

Importance: Traumatic brain injury (TBI) is a massive public health problem. While evidence-based guidelines directing the prehospital treatment of TBI have been promulgated, to our knowledge, no studies have assessed their association with survival. Objective: To evaluate the association of implementing the nationally vetted, evidence-based, prehospital treatment guidelines with outcomes in moderate, severe, and critical TBI. Design, Setting, and Participants: The Excellence in Prehospital Injury Care (EPIC) Study included more than 130 emergency medical services systems/agencies throughout Arizona. This was a statewide, multisystem, intention-to-treat study using a before/after controlled design with patients with moderate to critically severe TBI (US Centers for Disease Control and Prevention Barell Matrix-Type 1 and/or Abbreviated Injury Scale Head region severity ≥3) transported to trauma centers between January 1, 2007, and June 30, 2015. Data were analyzed between October 25, 2017, and February 22, 2019. Interventions: Implementation of the prehospital TBI guidelines emphasizing avoidance/treatment of hypoxia, prevention/correction of hyperventilation, and avoidance/treatment of hypotension. Main Outcomes and Measures: Primary: survival to hospital discharge; secondary: survival to hospital admission. Results: Of the included patients, the median age was 45 years, 14 666 (67.1%) were men, 7181 (32.9%) were women; 16 408 (75.1% ) were white, 1400 (6.4%) were Native American, 743 (3.4% ) were Black, 237 (1.1%) were Asian, and 2791 (12.8%) were other race/ethnicity. Of the included patients, 21 852 met inclusion criteria for analysis (preimplementation phase [P1]: 15 228; postimplementation [P3]: 6624). The primary analysis (P3 vs P1) revealed an adjusted odds ratio (aOR) of 1.06 (95% CI, 0.93-1.21; P = .40) for survival to hospital discharge. The aOR was 1.70 (95% CI, 1.38-2.09; P < .001) for survival to hospital admission. Among the severe injury cohorts (but not moderate or critical), guideline implementation was significantly associated with survival to discharge (Regional Severity Score-Head 3-4: aOR, 2.03; 95% CI, 1.52-2.72; P < .001; Injury Severity Score 16-24: aOR, 1.61; 95% CI, 1.07-2.48; P = .02). This was also true for survival to discharge among the severe, intubated subgroups (Regional Severity Score-Head 3-4: aOR, 3.14; 95% CI, 1.65-5.98; P < .001; Injury Severity Score 16-24: aOR, 3.28; 95% CI, 1.19-11.34; P = .02). Conclusions and Relevance: Statewide implementation of the prehospital TBI guidelines was not associated with significant improvement in overall survival to hospital discharge (across the entire, combined moderate to critical injury spectrum). However, adjusted survival doubled among patients with severe TBI and tripled in the severe, intubated cohort. Furthermore, guideline implementation was significantly associated with survival to hospital admission. These findings support the widespread implementation of the prehospital TBI treatment guidelines. Trial Registration: ClinicalTrials.gov identifier: NCT01339702.