S-100ß does not predict outcome after mild traumatic brain injury.

OBJECTIVE: To determine the usefulness of S-100ß, a marker for central nervous system damage, in the prediction of long-term outcomes after mild traumatic brain injury (MTBI) Hypothesis: Mid- and long-term outcomes of MTBI (i.e. 3, 6 and 12 months post-injury and return-to-work or school (RTWS)) may be predicted based on pre-injury and injury factors as well as S-100ß. METHODS: MTBI subjects without abnormal brain computed tomography requiring intervention, focal neurological deficits, seizures, amnesia > 24 hours and severe or multiple injuries were recruited at a level I trauma centre. Admission S-100ß measurements and baseline Concussion Symptom Checklist were obtained. Symptoms and RTWS were re-assessed at follow-up visits (3-10 days and 3, 6 and 12 months). Outcomes included number of symptoms and RTWS at follow-up. Chi-square tests, linear and logistic regression models were used and p < 0.05 was considered statistically significant. RESULTS: One hundred and fifty of 180 study subjects had S-100ß results. Eleven per cent were unable to RTWS at 12 months. S-100ß levels were not associated with post-concussive symptomatology at follow-up. In addition, no association was found between S-100ß levels and RTWS. CONCLUSION: Amongst MTBI patients, S-100ß levels are not associated with prolonged post-concussive syndrome or the inability to RTWS.

Scene mobility status as a predictor of injury severity and mortality due to vehicular crashes.

BACKGROUND: To examine the association of scene mobility status (SMS) and injury severity and mortality among motor vehicular crash (MVC) victims. METHODS: Adult MVC victims transported to medical facilities between 1997 and 2008 and included in the National Automotive Sampling System were studied. SMS was classified as follows: "ejected," "self-exited," "exited with assistance," "removed from the vehicle with decreased mental status," "removed due to perceived serious injury," and "removed for other reasons." Associations of SMS with Injury Severity Score and death were studied with contingency tables and multiple logistic regression models. RESULTS: A total of 62,634 cases representing 13,699,294 (weighted) cases were analyzed. Two percent of the cases were ejected, 38% self-exited, 18% exited with assistance, 4% removed with decreased mental status, 14% removed due to perceived serious injury, 1% other reasons, and 25% unknown. Mortality was highest among those ejected (8.7%). Those who self-exited and exited with assistance experienced a mortality of 0.02%. Injury Severity Score >8 occurred in 51% of those ejected, 37% of those removed with decreased mental status, 21% of those removed due to perceived serious injury, 4% of those who self-exited, and 5% of those exited with assistance. Multiple logistic regression revealed that those ejected, removed due to a low mental status or suspected injury, experienced higher adjusted odds ratios of dying than those who self-exited (odds ratio of 266 [69->999], 235 [61-903], and 66 (19-227), respectively). CONCLUSION: MVC occupants who "self-exited" or "exited with assistance" experienced a very low injury severity and mortality. Further efforts are needed to decrease the overtriaging of these patients.

Disparities in trauma center access of older injured motor vehicular crash occupants.

BACKGROUND: To evaluate whether older injured motor vehicular crash (MVC) occupants' access to trauma centers (TC) reflects the lower threshold suggested in triaging recommendations. METHODS: Adult front seat occupants of MVCs transported to a hospital from 1999 through 2006 included in the National Automotive Sampling System (NASS) were studied. Cases were classified by their age in years (≤60 years or >60 years). Younger and older injured MVC occupants were compared in relation to their likelihood of being transported to a TC. Multiple logistic regression models were built to adjust for confounders. RESULTS: A total of 35,830 cases representing 7,894,940 cases after weighting were analyzed. Older occupants were less likely to be transported to a TC than younger ones (47% vs. 55%, p < 0.0001). Older individuals were more likely to be restrained, passengers, and seated on the impacted side of lateral crashes. Injury severity was higher among the older group (mean Injury Severity Score, 4.1 vs. 3.1; p < 0.0001) and so was the resulting mortality (1.7% vs. 0.6%, p < 0.0001). Multiple logistic regression models after adjusting for confounders (i.e., other triage criteria) revealed a lower likelihood of TC transport (odds ratio, 0.75 [0.57-0.98]) for the older group. CONCLUSION: In contrast to the American College of Surgeons triaging recommendations, injured MVC occupants older than 60 years are less likely to be transported to a TC than their younger counterparts. Further studies should establish whether the lower access to TC experienced by the older population is a function of geographical factors, emergency medical services unconscious bias, or other factors.

Occupant and crash characteristics for case occupants with cervical spine injuries sustained in motor vehicle collisions.

BACKGROUND: Motor vehicle collisions (MVCs) are the leading cause of spine and spinal cord injuries in the United States. Traumatic cervical spine injuries (CSIs) result in significant morbidity and mortality. This study was designed to evaluate both the epidemiologic and biomechanical risk factors associated with CSI in MVCs by using a population-based database and to describe occupant and crashes characteristics for a subset of severe crashes in which a CSI was sustained as represented by the Crash Injury Research Engineering Network (CIREN) database. METHODS: Prospectively collected CIREN data from the eight centers were used to identify all case occupants between 1996 and November 2009. Case occupants older than 14 years and case vehicles of the four most common vehicle types were included. The National Automotive Sampling System's Crashworthiness Data System, a probability sample of all police-reported MVCs in the United States, was queried using the same inclusion criteria between 1997 and 2008. Cervical spinal cord and spinal column injuries were identified using Abbreviated Injury Scale (AIS) score codes. Data were abstracted on all case occupants, biomechanical crash characteristics, and injuries sustained. Univariate analysis was performed using a χ analysis. Logistic regression was used to identify significant risk factors in a multivariate analysis to control for confounding associations. RESULTS: CSIs were identified in 11.5% of CIREN case occupants. Case occupants aged 65 years or older and those occupants involved in rollover crashes were more likely to sustain a CSI. In univariate analysis of the subset of severe crashes represented by CIREN, the use of airbag and seat belt together (reference) were more protective than seat belt alone (odds ratio [OR]=1.73, 95% confidence interval [CI]=1.32-2.27) or the use of neither restraint system (OR=1.45, 95% CI=1.02-2.07). The most frequent injury sources in CIREN crashes were roof and its components (24.8%) and noncontact sources (15.5%). In multivariate analysis, age, rollover impact, and airbag-only restraint systems were associated with an increased odds of CSI. Using the population-based National Automotive Sampling System's Crashworthiness Data System data, 0.35% of occupants sustained a CSI. In univariate analysis, older age was noted to be a significant risk factor for CSI. Airbag-only restraint systems and both rollover and lateral crashes were also identified as risk factors for CSI. In addition, increasing delta v was highly associated with CSIs. In multivariate analysis, similar risk factors were noted. Of all the restraint systems, seat belt use without airbag deployment was found to be the most protective restraint system (OR=0.29, 95% CI=0.16-0.50), whereas airbag-only restraint was associated with the highest risk of CSI (OR=3.54, 95% CI=2.29-5.46). CONCLUSIONS: Despite advances in automotive safety, CSIs sustained in MVC continue to occur too often. Older case occupants are at an increased risk of CSI. Rollover crashes and severe crashes led to a much higher risk of CSI than other types and severity of MVCs. Seat belt use is very effective in preventing CSI, whereas airbag deployment may increase the risk of occupants sustaining a CSI. More protection for older occupants is needed and protection in both rollover and lateral crashes should remain a focus of the automotive industry. The design of airbag restraint systems should be evaluated so that they are not causative of serious injury. In addition, engineers should continue to focus on improving automotive design to minimize the risk of spinal injury to occupants in high severity crashes.

Crash test ratings and real-world frontal crash outcomes: a CIREN study.

OBJECTIVE: To establish whether the Insurance Institute for Highway Safety (IIHS) offset crash test ratings are linked to different mortality rates in real world frontal crashes. METHODS: The study used Crash Injury Research Engineering Network drivers of age older than 15 years who were involved in frontal crashes. The Crash Injury Research Engineering Network is a convenience sample of persons injured in crashes with at least one Abbreviated Injury Scale score of 3+ injury or two Abbreviated Injury Scale score of 2+ injuries who were either treated at a Level I trauma center or died. Cases were grouped by IIHS crash test ratings (i.e., good, acceptable, marginal, poor, and not rated). Those rated marginal were excluded because of their small numbers. Mortality rates experienced by these ratings-based groups were compared using the Mantel-Haenszel chi test. Multiple logistic regression models were built to adjust for confounders (i.e., occupant, vehicular, and crash factors). RESULTS: A total of 1,226 cases were distributed within not rated (59%), poor (12%), average (16%), and good (14%) categories. Those rated good and average experienced a lower unadjusted mortality rate. After adjustment by confounders, those in vehicles rated good experienced a lower risk of death (adjusted OR 0.38 [0.16-0.90]) than those in vehicles rated poor. There was no significant effect for "acceptable" rating. Other factors influencing the occurrence of death were age, DeltaV >or=70 km/h, high body mass index, and lack of restraint use. CONCLUSION: After adjusting for occupant, vehicular, and crash factors, drivers of vehicles rated good by the IIHS experienced a lower risk of death in frontal crashes.

Early predictors of postconcussive syndrome in a population of trauma patients with mild traumatic brain injury.

PURPOSE: The purpose of this analysis was to determine which of the initial symptoms after mild traumatic brain injury (MTBI) can best predict the development of persistent postconcussive syndrome (PCS). METHODS: One hundred eighty MTBI patients admitted to a level I trauma center were enrolled in a prospective study and 110 followed for 3 months. MTBI was defined as a Glasgow Coma Score of 13 to 15 with a transient loss of consciousness or report of being dazed or confused. PCS was defined as the persistence of four or more symptoms long term. Patients were screened at admission and at 3 days to 10 days and 3 months. Symptom checklists were administered to ascertain the presence of symptoms (cognitive, emotional, and physical) after concussion. For a subset of patients that were physically able, balance tests were also conducted. Stepwise logistic regression was used to identify which symptoms best predicted PCS. RESULTS: The mean age of the subjects was 35 years, and 65% were men. Physical symptoms were the most prevalent in the 3 days to 10 days postinjury with most declining thereafter to baseline levels. Emotional and cognitive symptoms were less prevalent but more likely to remain elevated at 3 months; 41.8% of subjects reported PCS at 3 months. The strongest individual symptoms that predicted long-term PCS included anxiety, noise sensitivity (NS), and trouble thinking; reported by 49%, 27%, and 31% of the subjects at 3 days to 10 days, respectively. In multivariate regressions including age, gender, and early symptoms, only anxiety, NS and gender remained significant in the prediction of PCS. Interactions revealed that the effect of anxiety was seen primarily among women. NS had an odds ratio of 3.1 for PCS at 3 months. CONCLUSIONS: After MTBI, anxiety among women and NS are important predictors of PCS. Other physical symptoms, while more prevalent are poor predictors of PCS.

Suicides, homicides, and unintentional injury deaths after trauma center discharge: cocaine use as a risk factor.

BACKGROUND: : To study whether trauma center patients with positive toxicology findings for cocaine-positive (COC+) are at a higher risk for suicide, homicide, and unintentional injury death after discharge than cocaine-negative (COC+) trauma patients. METHODS: : Patients admitted between July 1983 and June 1995 and discharged alive from a level I trauma center were prospectively followed up for 1.5 years to 14.5 years. The occurrence of suicide, homicide, and unintentional injury death was explored in relation to COC+ status at admission using Cox proportional hazards methodology. Models included possible confounders. Interactions with each of the main effects were explored. RESULTS: : Of the 27,399 admissions, 21,500 had urine COC toxicology testing performed and were included in the study. COC was positive in 11.4% of the studied population. COC+ patients were significantly younger, with 72% of COC+ versus 43% of COC- in the 25 to 44 years age group. COC+ patients were more likely to be men, positive for alcohol, and intentional injury victims. COC+ status was not associated with subsequent suicide. Furthermore, the COC+ status association with subsequent homicide became nonsignificant after adjusting for confounders. Unadjusted COC+ status was associated with unintentional injury death (odds ratio = 1.65 [1.14-2.40]). Interactions were found in the association with unintentional injury death such that COC+ status tripled the odds of injury death (odds ratio = 2.75 [1.58-4.78]) among the alcohol-negative patients within the 25 to 45 years age group. CONCLUSION: : COC+ trauma patients are at an increased risk of subsequent unintentional injury death after discharge from a trauma center. Suicide and homicide occurrence seems to be unaffected.

Expected differences and unexpected commonalities in mortality, injury severity, and injury patterns between near versus far occupants of side impact crashes.

OBJECTIVE: To compare injury patterns and outcomes of near- and far-side collisions. METHODS: Near- and far-side occupants in the Crash Injury Research and Engineering Network (CIREN) were compared for mortality and the occurrence of severe injuries (maximum abbreviated injury scale [MAIS] 3+). Regression models, adjusting for confounders, examined death and MAIS 3+ injuries as outcomes and near- or far-side position as an independent variable. CIREN findings were compared with those of the Crash Outcome Data Evaluation System (CODES), and the Maryland Automated Accident Reporting System. RESULTS: Of the 380 cases, 72% were in the near and 28% in the far position. Mortality was similar between groups within CIREN. Near-side occupants experienced a higher frequency of MAIS 3+ injuries for the thorax, abdomen, and lower extremities, and fewer MAIS 3+ head injuries than far-side occupants (35% vs. 46%, p = 0.06). Regression models revealed similar risk of MAIS 3+ head injuries among near- and far-side occupants. The most common structures contacting the head in far-side crashes (N = 62) were opposite side structures (52%) and other occupants (13%). Similar risks of head injuries among near- and far-side occupants were observed for the CODES data; however, lower risks of death were present among far-side drivers involved in crashes, based on CODES and Maryland Automated Accident Reporting System. CONCLUSIONS: Despite a lower incidence of thoracic, abdominal, and lower extremity injuries, far-side occupants experienced a similar risk of head injuries to that of near-side occupants. Contact patterns suggest that restraint systems fail to keep far-side occupants' heads from striking opposite side structures or other occupants.

Crash and occupant predictors of pulmonary contusion.

OBJECTIVES: Pulmonary contusions (PCs) are a common injury sustained in motor vehicle collisions. The crash and occupant characteristics of PC in motor vehicle collisions are currently unknown. Additionally, the clinical significance and the impact on mortality have not been determined. METHODS: A retrospective review of the Crash Injury Research and Engineering Network database with inclusion criteria of frontal (F) and near-side lateral (L) crashes involving occupants older than 15 years, yielded 2,184 case occupants. Pearson's chi and multivariate logistic regression were used with a p < 0.05 conferring statistical significance. RESULTS: Median age was 38 years, 80% were drivers and mortality was 16%. Forty-nine percent of case occupants were not wearing lap-shoulder belts. Chest trauma was sustained by 1,131 (52%), of whom 379 had PC. Crash characteristics included: 38 kph median change in velocity (delta V), 72% frontal deformation, and 35% struck a fixed object. Injury characteristics included median Injury Severity Score 17 with the following Abbreviated Injury Score (AIS) >2 injuries: thoracic 40%, abdominal 19%, and head 24%. Univariate predictors of PC included: age <25, male, higher Injury Severity Score, fatality, delta V >45 kph, L impacts, and collision with fixed object. PC was significantly associated with occupant compartment intrusion in F but not L crashes. In multivariate analysis, significant predictors of PC included: age <25 (odds ratios [OR] = 1.5), delta V >45 kph (OR = 1.9), and fixed object (frontal crash only) (OR = 1.8). Controlling for head, spine, abdominal, and extremity injuries AIS >2, PC was not a statistically significant risk factor for mortality. This was consistent whether or not another AIS >2 thoracic injury was present. The effectiveness of side-impact airbags was not evaluated due to the small sample size. CONCLUSIONS: Crash severity as demonstrated by higher delta V was strongly associated with PC in all crashes. Frontal crashes with a fixed object or intrusion are more likely to result in a PC. The risk of PC is greatly increased in near-side lateral impacts regardless of intrusion or object struck; suggesting occupant proximity may be the most important factor. Further investigations of the efficacy of side airbags as a counter measure should be considered and continued public education of the efficacy of lap-shoulder restrains should continue. Unexpectedly, although a marker for crash severity, PC is not an independent marker of mortality.

Injury severity and outcome of overweight and obese patients after vehicular trauma: a crash injury research and engineering network (CIREN) study.

BACKGROUND: This study investigates the influence of overweight and obesity on outcome from vehicular trauma. METHODS: All Crash Injury Research and Engineering Network patients older than 16 years involved in frontal and lateral crashes between 2000 and 2005 in vehicles with front airbags were included (n = 1,615). Obese, overweight, and normal-weight patients were compared in relation to injury severity score (ISS) and mortality using the Bonferroni method for multiple comparisons and the chi test. Control variables included patient factors (gender, age, and height) and crash factors (curb weight, change in velocity [DeltaV], principal direction of force, and restraint use). Multivariate analysis was performed for both ISS and mortality using linear and logistic regression, respectively. An alpha value of 0.05 was used for all statistics. RESULTS: Univariate analysis showed no difference in ISSs between groups based on body mass index. Mortality was higher for obese and overweight than for normal-weight patients (20.5%, 16.2%, and 9.4%, respectively). Multiple linear regression revealed a positive association of ISS with overweight (parameter estimate 2.44, p = 0.009) but not with obese patients. Crash factor adjusted odds of dying were 2.08 (CI 1.43-3.04) for overweight and 3.17 (CI 2.14-4.72) for obese patients. Injury-severity-adjusted odds of dying were 1.87 (CI 1.17-3.01) for overweight and 3.89 (CI 2.38-6.45) for obese patients. CONCLUSION: After adjusting for age, gender, and crash factors, overweight patients (but not obese patients) experienced more severe injuries. Obese and overweight patients experience higher unadjusted and adjusted mortality rates.

School suspensions, injury-prone behaviors, and injury history.

PURPOSE: To investigate the association of history of school suspension (HSS) to risky behaviors and injury history. METHODS: Adult patients admitted to a Level I trauma center (n = 774) were assessed for demographics, socioeconomic status, educational history, risky behaviors (infrequent seat belt use, drinking and driving, binge drinking, and speeding for a thrill), substance abuse disorders, and prior injury history. Student's t test and chi statistics were used to compare subjects with and without a HSS in relation to risky behaviors and injury history (alpha = 0.05). Logistic regression models were constructed with each risky behavior and injury history as the outcome adjusting for demographics, socioeconomic status, and substance abuse disorders. RESULTS: Patients with HSS (n = 260) were significantly younger, more likely to be male, not married, low income, Black, unemployed, smokers, and alcohol and drug dependent than patients without such history (n = 514). They had higher rates of binge drinking (66% vs. 33%), infrequent seat belt use (50% vs. 26%), drinking and driving (24% vs. 12%), and driving fast for a thrill (21% vs. 8%). Similarly, they had more frequent previous history of vehicular injuries (44% vs. 31%) and assaults (36% vs. 16%). Multivariate models revealed school suspension to be associated with infrequent seat belt use (Odds ratio [OR] = 2.02 [1.44-2.83]), binge drinking (OR = 1.95 [1.25-3.04]), speeding for a thrill (OR = 1.83 [1.15-2.92]), prior vehicular injuries (OR = 1.46 [1.06-2.02]), and assaults (OR = 1.67 [1.13-2.47]). CONCLUSION: HSS is associated with risky behaviors, and history of prior vehicular crashes and assaults.

Delta V, principal direction of force, and restraint use contributions to motor vehicle crash mortality.

OBJECTIVE: To measure the combined contribution of change in velocity (Deltav), principal direction of force (PDOF), and restraint use on mortality after vehicular trauma. METHODS: The Crash Injury Research and Engineering Network population includes patients <8 years old with one injury with an Abbreviated Injury Scale score >or=3 or with two injuries with an Abbreviated Injury Scale score >or=2, who were occupants of a vehicle. Patients 15 years or younger; in rear collisions; back seat occupants; in crashes with Deltav >80 km/h, unknown Deltav, or unknown PDOF; or in vehicles without airbags were excluded. Mortality was analyzed in relation to Deltav (km/h), restraint use, and PDOF using chi2. Multiple logistic regression models were built, including possible confounders (body mass index, age, gender) and interactions were explored. An [alpha] = 0.05 was used for all statistics. RESULTS: A total of 1,261 cases were included. Mortality was higher for unrestrained than for restrained patients (17% vs. 9%) and was higher for lateral than for frontal impact patients (17% vs. 11%). Higher mortality rates were also observed for Deltav 40-80 km/h than for Deltav <40 km/h (17% vs. 9%). Multiple logistic regression findings, after adjusting for age, gender, and body mass index, revealed significant effects of lateral PDOF (odds ratio [OR] 3.06 [2.03-4.61]), unrestrained status (OR 2.95 [2.01-4.38]), and Deltav 40-80 km/h (OR 3.65 [2.44-5.44]). Effect modification was found between PDOF and Deltav. CONCLUSIONS: A Deltav 40 km/h to 80 km/h, lack of restraint use, and lateral impact significantly affects mortality. A synergistic effect was found between Deltav 40-80 km/h and lateral PDOF.

Social, behavioral and driving characteristics of injured pedestrians: a comparison with other unintentional trauma patients.

Pedestrian injuries represent 11% of all motor vehicle related injuries in the USA. This study attempts to define the epidemiology of the pedestrian victim. Patients admitted to a regional adult trauma center were interviewed and evaluated for substance abuse. Pedestrians were compared with the remaining unintentional trauma patients with regard to demographics, socioeconomics, possession of a driver's license, injury prone behaviors, risk taking dispositions, and BAC levels using the Student's t-test and Pearson's chi2 statistic (alpha=0.05). Multivariate logistic regression models were built with pedestrian mechanism as the outcome. When compared to the remaining unintentional trauma population (N=661), pedestrians (N=113) were significantly more likely to be black, not married, unemployed, binge drinkers, alcohol dependent, drug dependent, BAC+, to have a low income, low educational achievement, younger age, and to not have a driver license. Black race, unemployment of 1 year or more, never licensed, lapsed license, revoked license and BAC>200 mg/dl showed statistical significance in the multiple logistic regression. Pedestrians represent a sub-population with a low socioeconomic status and high incidence of substance abuse. Unemployment, not having a driver's license, black race, and a BAC>200 mg/dl were strongly linked to being an injured pedestrian.

Risk of psychoactive substance dependence among substance users in a trauma inpatient population.

One measure of a substance's addictive risk is the proportion of users who become dependent. This study evaluates the lifetime and current risk of substance dependence among lifetime substance users' among trauma inpatients and provides a relative ranking of addictive risk among the substances. Data on use of 8 substance groups (alcohol, opiates, marijuana, cocaine, other stimulants, sedative-hypnotics, hallucinogens, other drugs) were obtained by interview (Structured Clinical Interview for the DSM-III-R) from 1,118 adult trauma inpatients. Prevalence of lifetime dependence among lifetime users ranged from 80.7% for opiates and 70.9% for cocaine to 33.3% for hallucinogens and 26.6% for sedative-hypnotics. The rank order of addictive risk was similar to that found in the general population. Trauma inpatients had a higher absolute addictive risk than the general population, comparable to the risk found in patients in treatment for substance use disorders, suggesting the importance of screening trauma inpatients for substance dependence.

Sociodemographic characteristics associated with substance use status in a trauma inpatient population.

Substance use is significantly associated with physical injury, yet relatively little is known about the prevalence of specific substance use disorders among trauma patients, or their associated sociodemographic characteristics. We evaluated these issues in an unselected sample of 1,118 adult inpatients at the University of Maryland Shock Trauma Center, Baltimore, MD, who were interviewed with the psychoactive substance use disorder section of the Structured Clinical Interview for DSM-III-R. Among trauma inpatients, lifetime alcohol users (71.8% of subjects) were more likely male; users of illegal drugs (45.3%) were also more likely to be younger, unmarried, and poor. Patients with current drug abuse/dependence (18.8%) were more likely to be non-white, less educated, and poor; those with current alcohol abuse/dependence (32.1%) were also more likely male, unmarried, and older. These findings highlight the need for screening for substance use disorders in trauma settings and referral of patients to substance abuse treatment programs.

The association between age, injury, and survival to hospital among a cohort of injured motorcyclists.

Despite the significant increase in mortality among older motorcyclists during the past decade, few studies have addressed specific injuries or mortality rates among all those injured. The purpose of this study is to describe the crash and injury characteristics among a cohort of motorcyclists injured in Maryland, and to determine the influence of age and crash type on mortality, injury patterns, and place of death (scene vs. hospital). Possible biases introduced by studying only those hospitalized are described. Based on the findings, specific injury prevention strategies for older vs. younger riders are proposed.

Effect of Maryland's 2011 Alcohol Sales Tax Increase on Alcohol-Positive Driving.

INTRODUCTION: The 2011 Maryland alcohol sales tax increase from 6% to 9% provided an opportunity to evaluate the impact on rates of alcohol-positive drivers involved in injury crashes. METHODS: Maryland police crash reports from 2001 to 2013 were analyzed using an interrupted time series design and a multivariable analysis employing generalized estimating equations models with a negative binomial distribution. Data were analyzed in 2014-2015. RESULTS: There was a significant gradual annual reduction of 6% in the population-based rate of all alcohol-positive drivers (p<0.03), and a 12% reduction for drivers aged 15-20 years (p<0.007), and 21-34 years (p<0.001) following the alcohol sales tax increase. There were no significant changes in rates of alcohol-positive drivers aged 35-54 years (rate ratio, 0.98; 95% CI=0.89, 1.09). Drivers aged ≥55 years had a significant immediate 10% increase in the rate of alcohol-positive drivers (rate ratio, 1.10; 95% CI=1.04, 1.16) and a gradual increase of 4.8% per year after the intervention. Models using different denominators and controlling for multiple factors including a proxy for unmeasured factors found similar results overall. CONCLUSIONS: The 2011 Maryland alcohol sales tax increase led to a significant reduction in the rate of all alcohol-positive drivers involved in injury crashes especially among drivers aged 15-34 years. This is the first study to examine the impact of alcohol sales taxes on crashes; previous research focused on excise tax. Increasing alcohol taxes is an important but often neglected intervention to reduce alcohol-impaired driving.

Risk perception and impulsivity: association with risky behaviors and substance abuse disorders.

Low risk perception and high impulsivity, in conjunction with substance abuse disorders, are associated with the occurrence of injury in the general population. The study described in this article investigated the association of risk perception and impulsivity with risky behaviors (infrequent seat belt use, drinking and driving, riding with a drunk driver, binge drinking, and speeding for the thrill) among adults with unintentional blunt trauma. Patients (N = 756) were assessed for substance abuse disorders and participation in risky behaviors. Risk perception and impulsivity were measured by questionnaire. Pearson's chi-square statistic was used to investigate risk perception, impulsivity, substance abuse, and possible confounders relative to risky behaviors. Odds ratios were calculated using logistic regression methodology. Univariate results indicated that low risk perception and high impulsivity were significant risk factors for risky behaviors. After adjustment for confounding factors, low risk perception and high impulsivity remained significantly associated with risky behaviors in the trauma patient population.

Injury patterns and severity among hospitalized motorcyclists: a comparison of younger and older riders.

In recent years there has been a significant increase in mortality among motorcyclists, especially older riders (40+ years). However, few studies have compared the nature and severity of injuries sustained by older vs. younger cyclists. The purpose of this analysis was to determine differences, if any, in injury patterns to older vs. younger motorcyclists and to explore rider, vehicle, and environmental factors associated with these differences. Older riders were found to have a significantly higher incidence of thoracic injury, especially multiple thoracic injuries, and specifically multiple rib fractures. Older motorcyclists were also more likely to ride larger motorcycles, and were more involved in collisions involving overturning or striking highway structures. Large engine sizes were associated with increased risk of head and thoracic injuries, but not abdominal injuries. The magnitude of increased risks related to 1000+ cc engine size was higher among older motorcyclists than younger motorcyclists.

Crash culpability and the role of driver blood alcohol levels.

Twenty years ago the American Medical Association reported the relationship between blood alcohol concentration (BAC) and crash causation. This study addresses culpability, age, gender and BAC in a population of drivers injured in motor vehicle crashes. Five years of hospital and crash data were linked, using probabilistic techniques. Trends in culpability were analyzed by BAC category. Given BAC level, the youngest and oldest drivers were more likely to have caused their crash. Women drivers had significantly higher odds of culpability at the highest BAC levels. Seatbelt use was also associated with culpability, perhaps as a marker for risk-taking among drinkers.