Blood alcohol tests, prevalence of involvement, and outcomes following brain injury

Application of multiple testing procedures for identifying relevant comorbidities, from a large set, in traumatic brain injury for research applications utilizing big health-administrative data

Background

Multiple testing procedures (MTP) are gaining increasing popularity in various fields of biostatistics, especially in statistical genetics. However, in injury surveillance research utilizing the growing amount and complexity of health-administrative data encoded in the International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10), few studies involve MTP and discuss their applications and challenges.

Objective

We aimed to apply MTP in the population-wide context of comorbidity preceding traumatic brain injury (TBI), one of the most disabling injuries, to find a subset of comorbidity that can be targeted in primary injury prevention.

Methods

In total, 2,600 ICD-10 codes were used to assess the associations between TBI and comorbidity, with 235,003 TBI patients, on a matched data set of patients without TBI. McNemar tests were conducted on each 2,600 ICD-10 code, and appropriate multiple testing adjustments were applied using the Benjamini-Yekutieli procedure. To study the magnitude and direction of associations, odds ratios with 95% confidence intervals were constructed.

Results

Benjamini-Yekutieli procedure captured 684 ICD-10 codes, out of 2,600, as codes positively associated with a TBI event, reducing the effective number of codes for subsequent analysis and comprehension.

Conclusion

Our results illustrate the utility of MTP for data mining and dimension reduction in TBI research utilizing big health-administrative data to support injury surveillance research and generate ideas for injury prevention.

Combined Effects of Repetitive Mild Traumatic Brain Injury and Alcohol Drinking on the Neuroinflammatory Cytokine Response and Cognitive Behavioral Outcomes

The relationship between alcohol consumption and traumatic brain injury (TBI) often focuses on alcohol consumption increasing the likelihood of incurring a TBI, rather than alcohol use outcomes after TBI. However, patients without a history of an alcohol use disorder can also show increased problem drinking after single or multiple TBIs. Alcohol and mild TBI share diffuse deleterious neurological impacts and cognitive impairments; therefore, the purpose of these studies was to determine if an interaction on brain and behavior outcomes occurs when alcohol is consumed longitudinally after TBI. To examine the impact of mild repetitive TBI (rmTBI) on voluntary alcohol consumption, mice were subjected to four mild TBI or sham procedures over a 2 week period, then offered alcohol (20% v/v) for 2 weeks using the two-bottle choice, drinking in the dark protocol. Following the drinking period, mice were evaluated for neuroinflammatory cytokine response or tested for cognitive and behavioral deficits. Results indicate no difference in alcohol consumption or preference following rmTBI as compared to sham; however, increases in the neuroinflammatory cytokine response due to alcohol consumption and some mild cognitive behavioral deficits after rmTBI and alcohol consumption were observed. These data suggest that the cytokine response to alcohol drinking and rmTBI + alcohol drinking is not necessarily aggregate, but the combination does result in an exacerbation of cognitive behavioral outcomes.

Prognostic factors for unfavorable outcome after mild traumatic brain injury. A review of literature

BACKGROUND

Unfavorable outcomes occur in 15-20% of patients with mild traumatic brain injury (mTBI). Early identification of patients at risk of unfavorable outcome is crucial for suitable management to be initiated, increasing the chances of full recovery. Many studies have been published on prognostic factors, but are not of a high level of evidence and certainty. A number of factors have been proposed and predictive models have been constructed that, although attractive, have not yet been externally validated.

OBJECTIVES

A review of literature (systematic search of PubMed and Google Scholar) assembled relevant available information about prognostic factors for unfavorable outcome after mTBI. We discuss the consistency of these findings, and the possibility and difficulty of using these factors in a daily practice.

RESULTS

It appears that the strongest and most consistent predictors are the number, severity and duration of symptoms present in the first few days after the trauma.

Updating the risk profile of fatal head trauma: an autopsy study with focus on age- and sex-dependent differences

Fatal head trauma (FHT) represents one of the most frequent causes of death diagnosed in forensic pathology. However, profound statistic autopsy data on FHT is still sparse. Therefore, the purpose of this study was to investigate the circumstances and injury patterns of FHT with particular focus on age and sex, and additionally, to describe a recent risk profile of FHT. To this end, the forensic autopsy records of each FHT case at a large German university hospital during a 10-year period (2006-2015) were analyzed retrospectively (n = 372). The male-female ratio was 2.6:1. Regarding median age, females were 12.5 years older than males. Traffic-associated FHT represents the major mechanism of death, followed by fall-associated FHT. While accident was the major manner of death and presented a similar distribution of age and sex, homicides were the only subgroup with a significantly lower ratio between males and females. Skull fractures occurred in 78.2% and intracranial hemorrhages in 80.6% of all cases. In summary and partly in contrast to clinical data on head trauma, FHT still occurs predominantly in male individuals under the age of 45 years, in the context of traffic accidents and affected by alcohol intake. Improvements in traffic security as well as continuing surveillance of the incidence of FHT by forensic autopsies are necessary to further reduce the incidence of FHT.

Alcohol misuse and traumatic brain injury: a review of the potential roles of dopaminergic dysfunction and physiological underarousal post-injury

Although many researchers have demonstrated an increase in alcohol use following traumatic brain injury (TBI), there is also a body of research indicating that alcohol misuse predisposes one to injury and precedes TBI. Accordingly, various mechanisms have been proposed (e.g., self-medication, dampened levels of arousal, dopaminergic dysfunction, etc.) and variable results have emerged. This paper reviews the empirical evidence, for and against, TBI as a risk factor for alcohol misuse. In particular, this paper focuses on the brain-behavior relationships involved and examines the roles of physiological underarousal and dopaminergic dysfunction in the development of alcohol misuse after injury. Alcohol misuse impedes community reintegration among TBI survivors and creates additional rehabilitative challenges. Thus, in order to inform and improve treatment outcomes among this vulnerable population, a deeper understanding of the neural mechanisms implicated is needed.

The Young Male Syndrome-An Analysis of Sex, Age, Risk Taking and Mortality in Patients With Severe Traumatic Brain Injuries

Higher risk taking is particularly characteristic for males between 15 and 35 years, the age when intrasexual competition is the strongest. This fitness-maximizing strategy, however, also has negative consequences; previous data revealed that males have a significantly higher tendency to die in accidents. This retrospective study aimed to assess whether age-related risk taking, often associated with the reproductive competition between males, and referred to as the Young Male Syndrome (YMS), may play a role in the high incidence of severe traumatic brain injury (sTBI) in young males. Derived from the available evidence and the main assumptions of the YMS, we expected that men, especially when they are in the age when their reproductive potential peaks, are more likely to suffer sTBI from highly risky behaviors that also lead to higher mortality. It was also expected that alcohol intoxication makes the demographic pattern of sTBI even more similar to what previous research on the YMS implies. We analyzed demographic data of patients with sTBI (N = 365) registered in a clinical database. To this end, we built Generalized Linear Mixed Models (GLMM) to reveal which of the demographic characteristics are the best predictors for risky behaviors leading to sTBI and death as a consequence of the injury. The data suggest that younger people acquired sTBI from riskier behaviors compared to members of older age groups, irrespective of their sex. Moreover, being male and being alcohol intoxicated also contributed significantly to risk-taking behavior. Mortality rate after the injury, however, increased with the age of the patient and did not depend on the riskiness of the behavior. The results indicate that the demographic distribution of the specific patient population in our focus cannot be simply explained by the YMS. However, higher incidence rates of males among the patients are in line with the core assumptions of the YMS. These data indicate that epidemiological studies should also take into consideration evolutionary theories and highlight the importance of age and sex specific prevention strategies.

Association of Alcohol With Mortality After Traumatic Brain Injury

Although alcohol exposure results in reduced mortality after traumatic brain injury (TBI) in animal models, clinical trials based on proposed mechanisms have been disappointing and have reported conflicting results. Methodological issues common to many of these clinical studies may have contributed to the spurious results. Our objective was to evaluate the association between blood alcohol concentration (BAC) and in-hospital mortality after TBI, and overcome methodological problems of prior studies. We conducted a retrospective cohort study on individuals treated for isolated TBI (n = 1,084) at the R Adams Cowley Shock Trauma Center (Baltimore, Maryland) from 1997 to 2012. We excluded individuals with injury to other body regions and examined multiple cutpoints of BAC. Our primary outcome was in-hospital mortality. In adjusted logistic regression models, the upper level of each blood alcohol categorization from 0.10 g/dL (odds ratio = 0.63, 95% confidence interval: 0.40, 0.97) through 0.30 g/dL (odds ratio = 0.25, 95% confidence interval: 0.08, 0.84) was associated with reduced risk of mortality after TBI compared with individuals with undetectable BAC. In sensitivity analyses among individuals without penetrating brain injuries (95% firearm-related) (n = 899), the protective association was eliminated. This study provides evidence that the observed protective association between BAC and in-hospital mortality after TBI resulted from bias introduced by inclusion of penetrating injuries.

Emergency department blood alcohol level associates with injury factors and six-month outcome after uncomplicated mild traumatic brain injury

The relationship between blood alcohol level (BAL) and mild traumatic brain injury (mTBI) remains in need of improved characterization. Adult patients suffering mTBI without intracranial pathology on computed tomography (CT) from the prospective Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot study with emergency department (ED) Glasgow Coma Scale (GCS) 13-15 and recorded blood alcohol level (BAL) were extracted. BAL≥80-mg/dl was set as proxy for excessive use. Multivariable regression was performed for patients with six-month Glasgow Outcome Scale-Extended (GOSE; functional recovery) and Wechsler Adult Intelligence Scale Processing Speed Index Composite Score (WAIS-PSI; nonverbal processing speed), using BAL≥80-mg/dl and <80-mg/dl cohorts, adjusting for demographic/injury factors. Overall, 107 patients were aged 42.7±16.8-years, 67.3%-male, and 80.4%-Caucasian; 65.4% had BAL=0-mg/dl, 4.6% BAL<80-mg/dl, and 30.0% BAL≥80-mg/dl (range 100-440-mg/dl). BAL differed across loss of consciousness (LOC; none: median 0-mg/dl [interquartile range (IQR) 0-0], <30-min: 0-mg/dl [0-43], ≥30-min: 224-mg/dl [50-269], unknown: 108-mg/dl [0-232]; p=0.002). GCS<15 associated with higher BAL (19-mg/dl [0-204] vs. 0-mg/dl [0-20]; p=0.013). On univariate analysis, BAL≥80-mg/dl associated with less-than-full functional recovery (GOSE≤7; 38.1% vs. 11.5%; p=0.025) and lower WAIS-PSI (92.4±12.7, 30th-percentile vs. 105.1±11.7, 63rd-percentile; p<0.001). On multivariable regression BAL≥80-mg/dl demonstrated an odds ratio of 8.05 (95% CI [1.35-47.92]; p=0.022) for GOSE≤7 and an adjusted mean decrease of 8.88-points (95% CI [0.67-17.09]; p=0.035) on WAIS-PSI. Day-of-injury BAL>80-mg/dl after uncomplicated mTBI was associated with decreased GCS score and prolongation of reported LOC. BAL may be a biomarker for impaired return to baseline function and decreased nonverbal processing speed at six-months postinjury. Future confirmatory studies are needed.

Traumatic Brain Injuries during Development: Implications for Alcohol Abuse

Traumatic brain injuries are strongly related to alcohol intoxication as by some estimates half or more of all brain injuries involve at least one intoxicated individual. Additionally, there is mounting evidence that traumatic brain injuries can themselves serve as independent risk factors for the development of alcohol use disorders, particularly when injury occurs during juvenile or adolescent development. Here, we will review the epidemiological and experimental evidence for this phenomenon and discuss potential psychosocial mediators including attenuation of negative affect and impaired decision making as well as neurochemical mediators including disruption in the glutamatergic, GABAergic, and dopaminergic signaling pathways and increases in inflammation.

The Differential Impact of Alcohol and Interpersonal Violence on the Severity of Violent Traumatic Brain Injuries among American Indians

Research shows connections between substance use and traumatic brain injury (TBI), high rates of substance use and interpersonal violence (IPV) in American Indians with TBI, and connections between IPV and TBI. This study assessed the effects of substance use at the time of a violent TBI and possible mediators such as American Indian race on injury severity (injury severity score [ISS]). A secondary data analysis of 3,351 individuals who experienced a TBI due to violence was conducted. American Indians with TBI were more likely to experience IPV (χ² = 4.19; p = .04) and had significantly higher blood alcohol content level (BAC) scores (t = - 16.78; p = .000) than other racial groups. A regression model explained 27% of the variance in ISS. Significant interaction terms uncovered positive relationships between: (a) American Indian race and ISS when the injury aetiology was not IPV and BAC scores were lower than the legal limit, and (b) IPV and ISS when patients were not American Indian. Alcohol was negatively associated with ISS among American Indians, suggesting that BAC may impact individuals with TBI differentially as a function of race.

Traumatic Brain Injury and Neuropsychiatric Complications

Traumatic brain injury (TBI) occurs when a blow or jolt to the head or a penetrating injury results in damage to the brain. It is the most frequent cause of hospitalization in young people with a higher prevalence in men. TBI is the leading cause of disability and mortality between the ages 1 and 45. TBI can be caused either by the direct result of trauma or due to a complication of the primary injury. The most common etiological factors for TBI are falls, road traffic accidents, violent physical assaults, and injuries associated with athletic activities. Following TBI, significant neurologic complications may occur which include seizures, dementia, Alzheimer's disease, and cranial nerve injuries. In addition, people may suffer from various psychiatric complications such as depression, posttraumatic stress disorder, generalized anxiety disorder, obsessive-compulsive disorder, and other cognitive and behavioral sequel that might significantly increase the comorbidity of the victims. Considering all of the above complications, TBI is one of the significant public health burdens. Literature has shown that only about 25% of people achieve long-term functional independence following TBI. In this paper, we focused not only on the epidemiology but also the etiology, complications following TBI and understanding their underlying pathogenesis. Further, we focused on analyzing the options to improve the treatment and rehabilitation following TBI in future.

Impact of day-of-injury alcohol consumption on outcomes after traumatic brain injury: A meta-analysis

Although a known risk factor for traumatic brain injury (TBI), alcohol has been found to both promote and protect against secondary brain damage. However, it is presently unclear whether the cognitive, psychological and medical/functional outcomes of adults who have consumed alcohol prior to sustaining a TBI differ from those who have not. This meta-analysis examined the outcomes of groups that differed in terms of their day-of-injury (DOI) blood alcohol levels (BALs) by comparing positive with zero BAL (BAL⁺/BAL^-) and high with low BAL (BAL^high/BAL^low) samples. The PubMed, PsycINFO, EMBASE, and Scopus databases were searched from inception until the end of March 2015. Hedge's g effects (continuous data) and odds ratios (categorical data) were calculated for 27 studies that compared either the outcomes of BAL⁺ and BAL^- groups or BAL^high and BAL^low groups. BAL⁺ was associated with significantly poorer cognitive outcomes (overall and on general tests) and higher levels of disability, and BAL^high was associated with shorter stays in intensive care. More generally, however, most effect sizes were small to low-moderate in size, non-significant and inconsistent in their direction. Although DOI alcohol consumption increases the risk of sustaining a TBI, it is not consistently associated with better or worse outcomes, other than subtle cognitive deficits; the source of which remains to be determined.

Use of Out-of-Hospital Ethanol Administration to Improve Outcome in Mass Methanol Outbreaks

STUDY OBJECTIVE

Methanol poisoning outbreaks are a global public health issue, with delayed treatment causing poor outcomes. Out-of-hospital ethanol administration may improve outcome, but the difficulty of conducting research in outbreaks has meant that its effects have never been assessed. We study the effect of out-of-hospital ethanol in patients treated during a methanol outbreak in the Czech Republic between 2012 and 2014.

METHODS

This was an observational case-series study of 100 hospitalized patients with confirmed methanol poisoning. Out-of-hospital ethanol as a "first aid antidote" was administered by paramedic or medical staff before the confirmation of diagnosis to 30 patients; 70 patients did not receive out-of-hospital ethanol from the staff (12 patients self-administered ethanol shortly before presentation).

RESULTS

The state of consciousness at first contact with paramedic or medical staff, delay to admission, and serum methanol concentration were similar among groups. The median serum ethanol level on admission in the patients with out-of-hospital administration by paramedic or medical staff was 84.3 mg/dL (interquartile range 32.7 to 129.5 mg/dL). No patients with positive serum ethanol level on admission died compared with 21 with negative serum ethanol level (0% versus 36.2%). Patients receiving out-of-hospital ethanol survived without visual and central nervous system sequelae more often than those not receiving it (90.5% versus 19.0%). A positive association was present between out-of-hospital ethanol administration by paramedic or medical staff, serum ethanol concentration on admission, and both total survival and survival without sequelae of poisoning.

CONCLUSION

We found a positive association between out-of-hospital ethanol administration and improved clinical outcome. During mass methanol outbreaks, conscious adults with suspected poisoning should be considered for administration of out-of-hospital ethanol to reduce morbidity and mortality.

Ethanol and isolated traumatic brain injury

The aim of this systematic review was to determine whether ethanol is neuroprotective or associated with adverse effects in the context of traumatic brain injury (TBI). Approximately 30-60% of TBI patients are intoxicated with ethanol at the time of injury. We performed a systematic review of the literature using a combination of keywords for ethanol and TBI. Manuscripts were included if the population studied was human subjects with isolated moderate to severe TBI, acute ethanol intoxication was studied as an exposure variable and mortality reported as an outcome. The included studies were assessed for heterogeneity. A meta-analysis was performed and the pooled odds ratio (OR) for the association between ethanol and in-hospital mortality reported. There were seven studies eligible for analysis. A statistically significant association favouring reduced mortality with ethanol intoxication was found (OR 0.78; 95% confidence interval 0.73-0.83). Heterogeneity among selected studies was not statistically significant (p=0.25). Following isolated moderate-severe TBI, ethanol intoxication was associated with reduced in-hospital mortality. The retrospective nature of the studies, varying definitions of brain injury, degree of intoxication and presence of potential confounders limits our confidence in this conclusion. Further research is recommended to explore the potential use of ethanol as a therapeutic strategy following TBI.

Complications associated with blood alcohol concentration following injury

Alcohol increases the risk of injuring oneself and others. However, following an injury there appears to be a benefit to alcohol in mediating the body's response to a traumatic injury and reducing mortality. The physiological mechanism underlying this reported association is poorly understood. One approach to explaining the pathways by which alcohol affects acute mortality following a traumatic injury is to identify differential prevalence of medical complications associated with increased mortality. The goal of this study was to evaluate the association between blood alcohol concentration and complications subsequent to a traumatic injury that are associated with increased in-hospital mortality. This study involved a retrospective analysis of traumatic injuries occurring between 2000 and 2009 as reported by all level I and II trauma units in the state of Illinois. The study includes all patients with blood alcohol toxicological examination levels ranging from zero to 500 mg/dL and meeting additional inclusion criteria (n = 84,974). A reduction in complications of cardiac and renal function by 23.5% and 30.0%, respectively, was attributable to blood alcohol concentration. In addition, blood alcohol concentration was associated with fewer cases of pneumothorax and convulsions. However, blood alcohol concentration continued to be positively associated with aspiration pneumonitis and acute pancreatitis in the final models. The net impact of alcohol following an injury is protective, largely attributable to a reduction in complications relating to cardiac and renal function. This study helps to explain the observed protective effect from blood alcohol concentrations in reducing in-hospital mortality after an injury, as reported in many studies.

Acute alcohol intoxication prolongs neuroinflammation without exacerbating neurobehavioral dysfunction following mild traumatic brain injury

Traumatic brain injury (TBI) represents a leading cause of death and disability among young persons with ∼1.7 million reported cases in the United States annually. Although acute alcohol intoxication (AAI) is frequently present at the time of TBI, conflicting animal and clinical reports have failed to establish whether AAI significantly impacts short-term outcomes after TBI. The objective of this study was to determine whether AAI at the time of TBI aggravates neurobehavioral outcomes and neuroinflammatory sequelae post-TBI. Adult male Sprague-Dawley rats were surgically instrumented with gastric and vascular catheters before a left lateral craniotomy. After recovery, rats received either a primed constant intragastric alcohol infusion (2.5 g/kg+0.3 g/kg/h for 15 h) or isocaloric/isovolumic dextrose infusion followed by a lateral fluid percussion TBI (∼1.4 J, ∼30 ms). TBI induced apnea and a delay in righting reflex. AAI at the time of injury increased the TBI induced delay in righting reflex without altering apnea duration. Neurological and behavioral dysfunction was observed at 6 h and 24 h post-TBI, and this was not exacerbated by AAI. TBI induced a transient upregulation of cortical interleukin (IL)-6 and monocyte chemotactic protein (MCP)-1 mRNA expression at 6 h, which was resolved at 24 h. AAI did not modulate the inflammatory response at 6 h but prevented resolution of inflammation (IL-1, IL-6, tumor necrosis factor-α, and MCP-1 expression) at 24 h post-TBI. AAI at the time of TBI did not delay the recovery of neurological and neurobehavioral function but prevented the resolution of neuroinflammation post-TBI.

Patient Characterization Protocols for Psychophysiological Studies of Traumatic Brain Injury and Post-TBI Psychiatric Disorders

Psychophysiological investigations of traumatic brain injury (TBI) are being conducted for several reasons, including the objective of learning more about the underlying physiological mechanisms of the pathological processes that can be initiated by a head injury. Additional goals include the development of objective physiologically based measures that can be used to monitor the response to treatment and to identify minimally symptomatic individuals who are at risk of delayed-onset neuropsychiatric disorders following injury. Research programs studying TBI search for relationships between psychophysiological measures, particularly ERP (event-related potential) component properties (e.g., timing, amplitude, scalp distribution), and a participant's clinical condition. Moreover, the complex relationships between brain injury and psychiatric disorders are receiving increased research attention, and ERP technologies are making contributions to this effort. This review has two objectives supporting such research efforts. The first is to review evidence indicating that TBI is a significant risk factor for post-injury neuropsychiatric disorders. The second objective is to introduce ERP researchers who are not familiar with neuropsychiatric assessment to the instruments that are available for characterizing TBI, post-concussion syndrome, and psychiatric disorders. Specific recommendations within this very large literature are made. We have proceeded on the assumption that, as is typically the case in an ERP laboratory, the investigators are not clinically qualified and that they will not have access to participant medical records.

The effect of blood alcohol level and preinjury chronic alcohol use on outcome from severe traumatic brain injury in Hispanics, anglo-Caucasians, and African-americans

OBJECTIVE

To examine (a) ethnic differences in blood alcohol level (BAL) and preinjury chronic alcohol use (PI-ETOH) within a severe closed head injury (CHI) sample and (b) the main and interaction effects of BAL, PI-ETOH, and ethnicity on functional outcome following severe CHI.

PARTICIPANTS

A total of 434 Hispanic, Anglo-Caucasian, and African-American individuals with severe CHI.

DESIGN

Retrospective cohort study.

SETTING

Consecutive admissions to a level 1 trauma center.

MAIN MEASURES

After admission to the trauma center, BAL was collected for each patient. Additional information regarding PI-ETOH was collected in a subset of patients (N = 116). Functional outcome was measured using the Disability Rating Scale (DRS) at 6 months after injury.

RESULTS

A one-way analysis of variance revealed ethnic differences in mean BAL. Hierarchical multiple regression indicated that BAL did not predict DRS outcomes after controlling for pertinent covariates. An interaction effect between PI-ETOH and ethnicity was observed, such that presence of chronic alcohol use predicted worse functional outcome for Anglo-Caucasians and African-Americans, but more favorable outcome for Hispanics.

CONCLUSIONS

Ethnic differences in BALs within our severe traumatic brain injury sample mirrored ethnic drinking patterns observed in the general population, with Hispanics having the highest BALs. A paradoxical relationship between PI-ETOH and functional outcome was observed for Hispanics.

Dose-response relationship between in-hospital mortality and alcohol following acute injury

Although the relationship between alcohol and injury incidence is well researched, there continues to be dispute about the relationship between alcohol and mortality following an injury. Findings from past studies have varied primarily because of methodological issues and have failed to characterize the dose-response relationship. The main objective of this study was to evaluate the dose response relationship of in-hospital mortality and blood alcohol concentration (BAC). This study was a retrospective analysis of traumatic injuries occurring between 1995 and 2009 as reported by all level 1 and 2 trauma units in the State of Illinois. The study includes all patients with blood alcohol toxicological examination levels ranging from zero to 500 mg/dl (N = 190,612). The Illinois trauma registry includes all patients sustaining traumatic injuries and admitted to a trauma center for ≥12 h. A total of 6733 patients meeting the inclusion criteria died following admission. Patients that were dead on arrival and those that died during the initial assessment within the emergency room were excluded. In the adjusted multivariable model, a decrease in in-hospital mortality was strongly associated with an increase in blood alcohol concentration (adjusted OR = 0.83 per 100 mg/dl units change in BAC; CI 95%: 0.80, 0.85; p < 0.001). The direction of the dose response relationship was consistent across the stratified models, with the exception of patients suffering burns. The largest reduction of in-hospital case fatality rates by blood alcohol concentration was observed among patients suffering penetrating or severe injuries (Injury Severity Score ≥ 16). In the clinical setting, it is important to understand not only how to recognize intoxicated patients, but also how alcohol may affect the course of treatment. The consistency of the findings across the multivariable models indicates that blood alcohol concentration is strongly associated with lower in-hospital mortality among those that survive long enough to receive treatment in specialized trauma units.

Traumatic brain injury and substance abuse: A review and analysis of the literature

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. Accidents are a major cause of brain injury, and many accidents are alcohol or drug related. Evidence indicates that a vast majority of victims test positive for alcohol or illicit drugs at the time of hospital admission. Research also suggests that a majority of TBI survivors were moderate to heavy drinkers pre-injury. This manuscript reviews literature on pre- and post-injury substance use patterns, abuse risk factors, and dangers of post-injury use. Assessment is discussed in detail with information provided on the need for quantitative assessment, records review, corroboration, and long-term monitoring. Information is also provided on critical features of treatment, prevention, and education, and on the role of psychologists in substance abuse assessment and treatment. The manuscript concludes with a section addressing issues, questions, and concerns commonly encountered by clinicians.

Isolated severe traumatic brain injuries: association of blood alcohol levels with the severity of injuries and outcomes

BACKGROUND

Traumatic brain injury is a common cause of death after traumatic insults. Alcohol intoxication is a recognized contributor to the occurrence of these injuries. The specific effects of alcohol exposure on injury severity and subsequent outcomes, however, remain controversial. The aim of this study was to investigate the relationship between blood alcohol levels (BAL) and outcomes in patients with isolated severe traumatic brain injuries (sTBI).

METHODS

During the calendar year 2003, as part of a pilot project, the Los Angeles County Department of Health Services obtained routine BAL on all patients transported to any of its 13 trauma centers. This study analyzes the effect of BAL on outcomes in patients with isolated sTBI (head Abbreviated Injury Scale (AIS) score >or=3; extracranial AIS score <3). The Low/No ethanol (ETOH) group included patients with negative or low (<0.08 mg/dL) BAL. Patients with BAL >or=0.08 mg/dL constituted the high ETOH group. Logistic regression was performed to determine whether alcohol levels had an independent association with outcomes.

RESULTS

There were 815 patients with isolated severe head injuries. Overall, 468 patients (57%) constituted the Low/No ETOH group, and 347 (43%) the high ETOH group. Alcohol levels were not significantly associated with severity of injury, hypotension at admission, Glasgow Coma Scale score, incidence of major complications, and intensive care unit or hospital length of stay. However, adjusted mortality was significantly lower in the high ETOH group when compared with the Low/No ETOH (8.9% vs. 17.1%; adjusted odds ratio: 0.60, 95% confidence interval: 0.37-0.96, p = 0.037). In the subgroup of patients with Injury Severity Score >15 the relative risk for mortality in the high ETOH group was significantly lower than in patients with Low/No ETOH. There was also an increased survival with high ETOH in patients with Injury Severity Score >25, but this was not statistically significant.

CONCLUSIONS

Among patients with isolated sTBI, BAL do not seem to be associated with overall injury severity, head injury severity, or the occurrence of major morbidities. Similarly, hospital and intensive care unit lengths are not affected by high admission BAL level. The adjusted overall in-hospital mortality, however, is significantly lower in patients presenting with the high BAL (>or=0.08 g/dL) after isolated sTBI.

Incidence of self-reported brain injury and the relationship with substance abuse: findings from a longitudinal community survey

BACKGROUND

Traumatic or serious brain injury (BI) has persistent and well documented adverse outcomes, yet 'mild' or 'moderate' BI, which often does not result in hospital treatment, accounts for half the total days of disability attributed to BI. There are currently few data available from community samples on the incidence and correlates of these injuries. Therefore, the study aimed to assess the 1) incidence of self-reported mild (not requiring hospital admission) and moderate (admitted to hospital)) brain injury (BI), 2) causes of injury 3) physical health scores and 4) relationship between BI and problematic alcohol or marijuana use.

METHODS

An Australian community sequential-cohort study (cohorts aged 20-24, 40-44 and 60-64 years at wave one) used a survey methodology to assess BI and substance use at baseline and four years later.

RESULTS

Of the 7485 wave one participants, 89.7% were re-interviewed at wave two. There were 56 mild (230.8/100000 person-years) and 44 moderate BI (180.5/100000 person-years) reported between waves one and two. Males and those in the 20-24 year cohort had increased risk of BI. Sports injury was the most frequent cause of BI (40/100) with traffic accidents being a greater proportion of moderate (27%) than mild (7%) BI. Neither alcohol nor marijuana problems at wave one were predictors of BI. BI was not a predictor of developing substance use problems by wave two.

CONCLUSIONS

BI were prevalent in this community sample, though the incidence declined with age. Factors associated with BI in community samples differ from those reported in clinical samples (e.g. typically traumatic brain injury with traffic accidents the predominate cause). Further, detailed evaluation of the health consequences of these injuries is warranted.

Serum ethanol levels: predictor of survival after severe traumatic brain injury

BACKGROUND

Recent studies have suggested that moderate doses of ethanol (ETOH) before traumatic brain injury (TBI) may have a neuroprotective role.

OBJECTIVE

: The objective of this study is to investigate the effects of serum ETOH levels on outcomes after TBI. Our hypothesis was that ETOH exposure is associated with improved survival in severe TBI patients and that the serum ETOH levels on admission correlate with survival.

METHODS

All patients sustaining severe TBI (head abbreviated injury score >or=3) admitted to the Surgical Intensive Care Unit at the Los Angeles County + University of Southern California Medical Center from January 2000 to December 2005 who had a serum ETOH level measured on admission were analyzed. Patients were classified into ETOH-positive and ETOH-negative groups, according to the serum ETOH levels and compared for differences in outcomes using logistic regression to adjust for clinically and statistically relevant confounding factors.

RESULTS

During the 5-year study period, 482 severe TBI patients admitted to the Surgical Intensive Care Unit at Los Angeles County + University of Southern California Medical Center had a serum ETOH level measured on admission. A total of 47% of severe TBI patients were tested for ETOH. ETOH levels were positive in 37% (179) and negative in 63% (303) of the TBI patients. The ETOH-positive group had a higher percentage of males (91% vs. 79%, p = 0.001), lower percentage of penetrating injuries (9% vs. 20%, p = 0.002), and lower injury severity score (25.7 +/- 11.5 vs. 28.4 +/- 14.1, p = 0.05). Overall mortality was significantly lower in the ETOH-positive group at 27% versus 40% (odds ratio = 0.55, 95% confidence interval: 0.37-0.82; p = 0.004). This survival benefit remained significant after multivariable analysis (adjusted odds ratio = 0.54, 95% confidence interval: 0.31-0.92; adjusted p = 0.02). The mean serum ETOH level was significantly higher for survivors than for nonsurvivors (0.11 +/- 0.21 vs. 0.05 +/- 0.10, p < 0.001). The serum ETOH levels significantly correlated with the probability of survival (r = 0.21, p < 0.001), but this correlation was not strong as shown by the low r value.

CONCLUSION

The results of this study suggest that elevated ETOH serum levels are independently associated with higher survival in patients with severe traumatic brain injuries. Additional research is required to further investigate the mechanism and potential therapeutic implications of this association.

Occurrence of severe and moderate traumatic brain injury in patients attended in a Brazilian Teaching Hospital: epidemiology and dosage of alcoholemy

This study aimed at observing aspects of epidemiology in order to investigate the use of alcohol in patients older than 18 with severe and moderate traumatic brain injury, which were attended in the Clinics Hospital of the University of Uberlândia. Positive alcoholemy was found in 39.3% of the patients. Of the 33 positive exams alcoholemy was found higher than 60 mg/dL in 28 (84.6%). There was not significant relation between alcoholemy levels and trauma severity. The major prevalence occurred on Saturdays nights. The most frequent types of external causes were transportation accidents (64.74) followed by accidental falls (17.27%) and physical aggression (16.55%). 93.9% of the patients with positive alcoholemy were men aged 20-29. 24.2% of the ones with positive alcoholemy died yet no significant difference was found in the study of the ones with negative alcoholemy (n=51) (p=0.93); RR= 0.9; IC95%=0.40-2.08.

An update on substance use and treatment following traumatic brain injury

Traumatic brain injury (TBI) is a leading cause of mortality and morbidity among young adults. Substance abusers constitute a disproportionate percentage of these patients. A history of substance abuse predicts increased disability, poorer prognosis, and delayed recovery. While consensus in the literature indicates that substance-abuse rates decline following injury, conflicting literature shows a significant history of brain injury in addicts. We reviewed the literature on substance abuse after TBI to explore the state of knowledge on TBI as a risk factor for substance abuse. While recent reviews regarding substance abuse in TBI patients concur that substance-abuse rates decline even after mild TBI, an emerging literature suggests mild TBI may cause subtle impairments in cognitive, executive, and decision-making functions that are often poorly recognized in early diagnosis and treatment. When combined with difficulties in psychosocial adjustment and coping skills, these impairments may increase the risk for chronic substance abuse in a subset of TBI patients. Preliminary results from veterans indicate these patterns hold in a combat-related post-traumatic stress disorder population with TBI. This increasingly prevalent combination presents a specific challenge in rehabilitation. While this comorbidity presents a challenge for the successful treatment and rehabilitation of both disorders, there is sparse evidence to recommend any specific treatment strategy for these individuals. Mild TBI and substance abuse are bidirectionally related both for risks and treatment. Further understanding the neuropsychiatric pathology and different effects of different types of injuries will likely improve the implementation of effective treatments for each of these two conditions.

Comparability of Neuropsychological Test Profiles in Patients with Chronic Substance Abuse and Mild Traumatic Brain Injury

The purpose of this study was to compare 104 patients with acute uncomplicated mild traumatic brain injury (MTBI) to a sample of 104 patients from an inpatient substance abuse program to determine whether these patients could be differentiated by their pattern of relative cognitive strengths and weaknesses. Patients were matched on age, education, and gender. Eight cognitive measures were used that included tests of attention, memory, and processing speed. There were no statistically significant differences between the two groups on any of the cognitive measures. Using a two-step cluster analysis procedure (i.e., hierarchical and k-means analyses), seven common profiles were identified. There was no significant difference in the proportions of patients from the MTBI or substance abuse group in each of the seven profiles. These results show that patients with uncomplicated MTBIs could not be reliably differentiated from patients with substance abuse problems on these cognitive measures. This is of particular concern for clinicians evaluating the neuropsychological effects of MTBI in individuals with a comorbid history of substance abuse.

Relationships among premorbid alcohol use, acute intoxication, and early functional status after traumatic brain injury

OBJECTIVE

To investigate the relationships among intoxication at time of injury, preinjury history of problem drinking, and early functional status in patients with traumatic brain injury (TBI).

DESIGN

Prospective cohort study.

SETTING

Acute inpatient TBI rehabilitation.

PARTICIPANTS

Participants were 1748 persons with TBI.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Blood alcohol levels (BALs) were obtained at admission to the emergency department, and a history of problem drinking was obtained through interview. Study outcomes, Disability Rating Scale (DRS), and FIM instrument scores were gathered at admission to inpatient rehabilitation.

RESULTS

Multivariate regression analysis revealed that BAL and a history of binge drinking were predictive of DRS, but not FIM, scores. A higher BAL was associated with poorer functional status on the DRS. Paradoxically, a history of binge drinking was associated with more intact functional status on the DRS.

CONCLUSIONS

The relationships among intoxication at time of injury, history of problem drinking, and early outcome after TBI were modest. Injury severity had a more significant association with TBI functional status.

Increased incidence of complications in trauma patients cointoxicated with alcohol and other drugs

BACKGROUND

Alcohol and drug intoxication is prevalent in trauma patients. Although intoxication and cointoxication can have a range of physiologic effects, their implications for clinical management are unclear. The current investigation aims to assess the effects of alcohol and substance use as well as the interaction between these two states on outcomes and in-hospital complications.

METHODS

All trauma patients with an Injury Severity Score (ISS) >or=12 during a 5-year period who were tested for both alcohol and other drugs were included. Alcohol-positive, drug-positive, and both-positive patients were compared with patients who tested negative. Logistic regression analysis was performed controlling for age and ISS to assess the relative contribution of intoxication or cointoxication in determining clinical outcomes and in-hospital complications.

RESULTS

For alcohol-positive and drug-positive patients, intoxication status did not appear to influence outcomes. However, cointoxicated individuals were found to have an increased incidence of complications overall (odds ratio [OR] = 2.06), an increased incidence of pneumonia specifically (OR = 3.34) and an increased incidence of the requirement for mechanical ventilation (OR = 2.37).

CONCLUSIONS

Cointoxication with alcohol and other drugs is a risk factor for increased in-hospital complications.

Effect of Intoxication Among Blunt Trauma Patients Selected for Head Computed Tomography Scanning

STUDY OBJECTIVE

We examine the prevalence and types of intracranial injuries sustained by intoxicated blunt trauma patients.

METHODS

The study was conducted as a secondary analysis of National Emergency X-Radiography Utilization Study II head injury database. Treating physicians prospectively assessed presenting signs and symptoms on all blunt trauma patients who underwent head computed tomography (CT). Intoxication status was determined by the examining physician and was based on a history of intoxication, positive toxicologic screen result, or physical evidence suggesting intoxication. Intracranial injury diagnoses were based on final CT interpretations provided by attending radiologists.

RESULTS

Intracranial injury was detected in 1,193 of the 13,728 enrolled patients (8.7%), and intoxication was evident in 3,356 (24.4%) patients. Physicians were unable to assess intoxication status in 620 individuals. Intracranial injury was present in 231 intoxicated patients (231/3,356; 6.9%; 95% confidence interval [CI] 6.0 to 7.8), 789 of 9,752 nonintoxicated patients (8.1%; 95% CI 7.6% to 8.6%), and 173 of the 620 patients who could not be assessed for intoxication (prevalence 27.9%; 95% CI 24.4% to 31.6%). Intracranial injury was identified in only 5 of 299 intoxicated patients (1.7%) who had normal neurological examination results and no evidence of trauma to the calvarium.

CONCLUSION

The prevalence of intracranial injury among intoxicated blunt trauma patients who are selected for head CT is lower than among nonintoxicated patients selected for imaging, which likely represents heightened concern in the presence of intoxication, even without other findings suggestive of intracranial injury. This conclusion is supported by the fact that few intoxicated patients with normal neurologic findings and no evidence of trauma to the calvarium had positive findings on CT imaging.

Ataxias

Gait disorders in elderly individuals are a major cause of falls and their attendant morbidities. Ataxia is one of the neurologic components of fall risk, as are inattention or confusion, visual impairment, vestibular impairment, subcortical white matter disease, parkinsonism, weakness, sensory loss, orthostasis or arrhythmia with alterations in blood pressure, pain, medication use, and environmental hazards. Ataxia in the geriatric population has many causes. Correctly identifying them can improve clinicians' ability to offer treatment and management strategies to patients and their families. The goals should be safe mobility and preserved activities of daily living.

Effects of ethanol on limited resuscitation in a model of traumatic brain injury and hemorrhagic shock

Object

Limited resuscitation following uncontrolled hemorrhagic shock (HS) has been associated with improved outcomes in various animal models, although it has not been previously studied in the setting of traumatic brain injury (TBI) and ethanol intoxication. The aim of the present study was to determine the effects of ethanol intoxication in a model of experimental TBI and HS treated with limited resuscitation.

Methods

After induction of anesthesia and the placement of instruments, swine were subjected to a fluid-percussion injury of 3 atm. Simultaneously, hemorrhage was induced from an arterial catheter via a computerized roller pump to a mean arterial blood pressure (MABP) of 50 mm Hg, at which time uncontrolled hemorrhage was induced by the creation of an aortic tear. When the MABP decreased to 30 mm Hg, limited resuscitation to a MABP of 60 mm Hg was begun. After 60 minutes, animals were aggressively resuscitated to baseline MABP levels. Two groups of animals were studied: those receiving tap water by gastrostomy tube and those receiving ethanol (4 g/kg) by gastrostomy tube. Animals were monitored for 180 minutes after TBI. Hemorrhage volumes were significantly greater in ethanol-infused animals (mean ± standard deviation, 41 ± 34 mm Hg) compared with tap water–infused animals (17 ± 18 mm Hg; p = 0.048). Resuscitation requirements were significantly higher and metabolic parameters significantly worse in the ethanol group. Survival time was also significantly decreased in the animals infused with ethanol (81 ± 60 minutes) compared with those infused with tap water (130 ± 51 minutes; p = 0.035).

Conclusions

Ethanol intoxication led to increased hemorrhage volume and worsened hemodynamic and metabolic profiles in this model of limited resuscitation after TBI and HS. Ethanol-exposed animals had increased resuscitation requirements and decreased survival times.

Traumatic brain injury and substance misuse: a systematic review of prevalence and outcomes research (1994-2004)

A systematic review of the evidence on substance misuse prevalence in patients with traumatic brain injury (TBI) and outcomes associated with this population is presented. Building upon an earlier review of the area by Corigan (1995), this review is limited to research published between 1994 and 2004. Psycinfo and Medline abstract databases were searched for English-language publications citing research from Western countries on the epidemiology and outcomes of adult TBI patients (aged 15 years or older). The majority of reviewed studies were undertaken in the USA and the investigation foci and methods used were multifarious, constraining the generalisation of the review findings. Prevalence for alcohol intoxication at time of injury in the review was found to be almost identical to that in Corrigan's review: 37-51% and 36-51%, respectively. Pre-TBI history of alcohol misuse was found to be less prevalent in the present as opposed to Corrigan's review: 37-51% and 55-66%, respectively. Outcome findings were mixed (also found by Corrigan), but mainly in the expected direction of poorer outcomes (neurological, medical, neuropsychological, and functional) in patients with pre-TBI substance misuse. Further research and implications for services are outlined.

ALCOHOL INTAKE AND THE PATTERN OF TRAUMA IN YOUNG ADULTS AND WORKING AGED PEOPLE ADMITTED AFTER TRAUMA

AIMS

To investigate the relationship of different patterns of alcohol intake to various types of trauma.

METHODS

We examined the associations of alcohol consumption in a series of 385 consecutive trauma admissions (278 men, 107 women, age range 16-49 years). Patients underwent clinical examinations, structured interviews on the amount and pattern of alcohol intake, and measurements of blood alcohol concentration (BAC).

RESULTS

On admission, 51% of the patients had alcohol in their blood. Binge drinking was the predominant (78%) drinking pattern of alcohol intake. Assaults, falls and biking accidents were the most frequent causes of trauma. Dependent alcohol drinking and binge drinking were found to be significantly more common among patients with head trauma than in those with other types of trauma (77% vs 59%, OR=2.38; 95% CI 1.50 to 3.77). The OR for sustaining head injury increased sharply with increasing BAC: 1-99 mg/dl (1.24; 95% CI 0.55-2.01), 100-149 mg/dl 1.64; 95% CI 0.71-3.77), 150-199 mg/dl (3.20; 95% CI 1.57-6.53) and >199 mg/dl (9.23; 95% CI 4.79-17.79).

CONCLUSIONS

Binge drinking is a major risk factor for head trauma among trauma patients. Assaults, falls and biking accidents are the commonest causes for such injuries. The relative risk for head injury markedly increases with increasing blood alcohol levels. Alcohol control measures should feature in policies aiming at the prevention of trauma-related morbidity and mortality.

Screening for substance abuse in individuals with traumatic brain injury

PRIMARY OBJECTIVE

To determine the utility of the CAGE, the Brief Michigan Alcohol Screening Test (BMAST) and the Substance Abuse Subtle Screening Inventory (SASSI-3) with individuals with traumatic brain injury (TBI), two studies were conducted examining the accuracy, sensitivity and specificity of these instruments.

RESEARCH DESIGN

Data from self-report instruments were compared to a clinical interview, Structured Clinical Interview for DSM-IV (SCID), to determine the accuracy, sensitivity and specificity.

METHODS AND PROCEDURES

Two studies were conducted. In study I, 100 individuals with TBI were screened for alcohol abuse using the CAGE and the resulting classifications were compared with those derived from the SCID. In study II, 223 individuals were screened for alcohol abuse and drug abuse using the BMAST and SASSI-3 and the results of these screenings were compared with diagnoses obtained by the SCID.

MAIN OUTCOMES AND RESULTS

The specificity of the self-report instruments was moderately high, ranging between 81-83%. The specificity of the CAGE for alcohol abuse both pre- and post-TBI was high, 96% and 86%, respectively. The sensitivity of the self-report instruments was most variable, ranging from 32-95%, with the SASSI face valid drug scale and the CAGE alcohol post-TBI indicating the most sensitivity, 95 and 91%, respectively.

CONCLUSIONS

The findings suggest that the CAGE may be useful in screening for alcohol abuse and the face valid drug sub-scale of the SASSI-3 may be useful in screening for drug abuse in individuals with TBI.

Alcohol abuse and traumatic brain injury: quantitative magnetic resonance imaging and neuropsychological outcome

Prior or concurrent alcohol use at the time of traumatic brain injury (TBI) was examined in terms of post-injury atrophic changes measured by quantitative analysis of magnetic resonance imaging (MRI) and neuropsychological outcome. Two groups of TBI subjects were examined: those with a clinically significant blood alcohol level (BAL) present at the time of injury (TBI + BAL) and those without a significant BAL (TBI-only). To explore the potential impact of both acute and chronic alcohol use, subjects in both groups were further clustered into one of four subgroups (NONE, MILD, MODERATE or HEAVY) based upon available information regarding their pre-injury alcohol use. One-way analysis of covariance (ANCOVA) and multiple analysis of covariance (MANCOVA) were used with subject grouping as the main factor. Age, injury severity as measured by Glasgow Coma Scale (GCS) score, years of education, total intracranial volume (TICV), and the number of days post-injury were included as covariates where appropriate. Increased general atrophy was observed in patients with (a) a positive BAL and/or (b) a history of moderate to heavy pre-injury alcohol use. In addition, performance on neuropsychological outcome variables (WAIS-R and WMS-R Index scores) was generally worse in the subgroups of patients with positive BAL and a history of preinjury alcohol use, as compared to the other TBI groups though not statistically significant. Implications of alcohol use, at the time of brain injury, are discussed.

Head injury among drug abusers: an indicator of co-occurring problems

Alcohol and other drug use has been associated with traumatic brain injury both as a contributing factor to the injury and as a complicating factor for rehabilitation. Brain injury is associated with an increase in mental health and other problems that may be related to drug and alcohol abuse and that may influence recovery. This study examined self-reports of 661 drug-abusing inmates with self-reported head injury, health problems and mental health problems. Three groups were examined for this study: those having no head injury, one head injury, and two or more head injuries. Results indicate that inmates with head injuries had a significantly greater number of health problems, higher levels of alcohol and marijuana use, and significantly more mental health problems including depression, anxiety, suicidal thinking, and difficulties in concentrating and controlling violent behavior. This study suggests that questions regarding head injuries during assessment may identify drug abusers who need a treatment approach that accommodates their co-occurring problems and difficulties with processing and complying with treatment interventions.

Brain and Spinal Cord Injury

Up to 50% of all trauma deaths in the United States involve significant injury to the brain or spinal cord. This chapter highlights the public health significance of traumatic brain and spinal cord injury and examines methodological issues in studies of the epidemiology of these injuries. It addresses methodological challenges in epidemiologic and clinical studies of brain and spinal cord injury, including difficulties in case ascertainment, differing approaches to brain injury classification, and measurement issues in brain injury severity and outcome scales. The chapter summarizes scientific literature addressing demographic and lifestyle risk factors for brain injury including age, sex, and alcohol consumption. External causes of traumatic brain and spinal cord injury are also discussed, including transportation-related injuries and increasingly recognized sports-related brain injuries.

Nighttime driving, passenger transport, and injury crash rates of young drivers

OBJECTIVE

This study examines the association of nighttime driving and the carrying of passengers with the rate of motor vehicle crashes that resulted in severe or fatal injury to young drivers in California before the implementation of a graduated licensing system.

METHOD

Passenger vehicle drivers aged 16 or 17 involved in injury crashes in California from 1 January 1993 to 30 June 1998 were identified through a police crash database. An induced exposure method was used to estimate driving exposure. Odds ratios for driver injury crashes were estimated with logistic regression.

RESULTS

Driving at night, driving without adult supervision, driving with passengers, using alcohol, being 16, and being male were associated with high rates of driver injury crash.

CONCLUSIONS

The injury crash rate for drivers aged 16 or 17 increases during nighttime hours and in the absence of adult supervision, with or without other passengers. Driving between 10 pm and midnight is particularly dangerous for young drivers. Nighttime driving restrictions that begin at 10 pm or earlier and restrictions on carrying passengers at any hour may increase the effectiveness of graduated licensing systems.

The magnitude and correlates of alcohol and drug use before traumatic brain injury

OBJECTIVE

To describe preinjury alcohol and drug use and opportunities for secondary prevention among persons with recent traumatic brain injury (TBI).

DESIGN

Survey.

SETTING

Acute inpatient rehabilitation program.

PARTICIPANTS

A total of 142 (91%) of 156 consecutive admissions who met inclusion criteria and were screened.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Alcohol and drug use questionnaires, alcohol problem questions, toxicology results, readiness to change, and treatment preference questions.

RESULTS

Subjects were on average 37 years old, 80% were men, and 80% were white. Fifty-nine percent of the sample was considered "at-risk" drinkers and, as a group, subjects reported a high degree of preinjury alcohol-related problems. Thirty-four percent reported recent illicit drug use, and 42 (37%) of 114 cases with toxicology results were positive for illicit drugs. Motivation to change alcohol use correlated positively with greater self-reported alcohol consumption and problem severity. Most at-risk drinkers wanted to change on their own, whereas a minority were interested in treatment or Alcoholics Anonymous.

CONCLUSION

Both alcohol abuse and drug use are common before TBI. Inpatient brain injury rehabilitation represents an important opportunity to identify and intervene in substance abuse problems.