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.

On equal footing: Trends in ankle/foot injuries for men vs. women.

OBJECTIVES: The objective of the current study was to examine trends in ankle/foot (A/F) injuries during the period 2001-2014, in order to determine whether the incidence of these injuries has changed and whether a previously identified difference in risk by gender still existed. In addition, other driver and crash-related risk factors were examined separately for men and women. METHODS: Passenger vehicle drivers aged 16+ were identified from NASS-CDS; weighted data were analyzed for model years 2001-2014. Model years (MY) were grouped as 2001-2004 (older) vs. 2005-2014 (newer), and drivers in frontal crashes were included. Ankle injuries included fractures and dislocations to the malleolus and distal tibia/fibula. Foot injuries included fractures and dislocations of the talus, calcaneus, and tarsal/metatarsal bones. Logistic regression models were constructed to identify risk factors, including MY, age, belt use, toepan/instrument panel intrusion, and body mass index (BMI) separately for each gender using odds ratios. RESULTS: The incidence of A/F injuries declined significantly between older and newer MY, especially for women. Whereas before MY 2005, ankle and foot injury risk was significantly higher for women than men, risks for ankle injury are now virtually the same for both genders, and women are only 1.2 times more likely than men to sustain a foot injury in a frontal crash. From multivariable regression models, however, it is apparent that there are different risk factors for A/F injuries for men vs. women. Body weight was a significant factor for both groups, but for men it was a risk only for those extremely obese, whereas for women those who were categorized as overweight were also at increased risk. Age greater than 55 was also found to be a risk factor for foot injuries among women but not men. For men and women, toepan intrusion remained the most important factor for both foot and ankle injuries, with significantly higher odds ratios noted for men. Foot pedals were a more likely injury source for women, whereas the toepan was more likely for men. In addition, belt use was protective for ankle injuries in women but not men. CONCLUSIONS: Significant declines in A/F injuries have been noted in recent years, especially for women, whose risks are now similar to those for men. However, significant risk factors remain for each gender, primarily related to body habitus (BMI) and toepan intrusion. Age was a risk factor for foot injuries among women, for whom the foot pedals were more likely to be an injury source. Toepan intrusion remains a major factor for both men and women, but, with the exception of 30+ cm of intrusion, odds ratios were primarily much higher for men in each category of intrusion.

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.

Aortic injuries in newer vehicles.

The occurrence of AI was studied in relation to vehicle model year (MY) among front seat vehicular occupants, age≥16 in vehicles MY≥1994, entered in the National Automotive Sampling System Crashworthiness Data System between 1997 and 2010 to determine whether newer vehicles, due to their crashworthiness improvements, are linked to a lower risk of aortic injuries (AI). MY was categorized as 1994-1997, 1998-2004, or 2005-2010 reflecting the introduction of newer occupant protection technology. Logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals for the association between AI and MY independent of possible confounders. Analysis was repeated, stratified by frontal and near lateral impacts. AI occurred in 19,187 (0.06%) of the 31,221,007 (weighted) cases, and contributed to 11% of all deaths. AIs were associated with advanced age, male gender, high BMI, near-side impact, rollover, ejection, collision against a fixed object, high ΔV, vehicle mismatch, unrestrained status, and forward track position. Among frontal crashes, MY 98-04 and MY 05-10 showed increased adjusted odds of AI when compared to MY 94-97 [OR 1.84 (1.02-3.32) and 1.99 (0.93-4.26), respectively]. In contrast, among near-side impact crashes, MY 98-04 and MY 05-10 showed decreased adjusted odds of AI [OR 0.50 (0.25-0.99) and 0.27 (0.06-1.31), respectively]. While occupants of newer vehicles experience lower odds of AI in near side impact crashes, a higher AI risk is present in frontal crashes.

Causation and outcomes of diaphragmatic injuries in vehicular crashes.

BACKGROUND: This study aimed to identify vehicular and crash factors associated with diaphragmatic injuries (DIs). METHODS: DI presence was analyzed among Crash Injury Research and Engineering Network vehicular occupants (age ≥ 16 years) in relation to occupant and crash factors. Contact points (i.e., components in direct contact with occupants) involved in injury causation were analyzed. Cases with and without DI were compared in relation to mortality, Injury Severity Score (ISS) and the occurrence of injuries with a maximum Abbreviated Injury Scale (MAIS) score of 3+. Student's t test, Wilcoxon test, χ(2), and multiple logistic regression were used for statistical analysis. RESULTS: Of a total of 2,344 cases with complete data for analysis, 80 cases (3.4%) experienced DI. Multiple logistic regression analysis revealed a significant association with the occurrence of DI for near lateral impact (odds ratio, 7.71 [4.20-14.58]) and change in velocity (ΔV) of 40 km/h or greater (odds ratio 2.58 [1.29-5.24]). The seat belt and steering wheel were the most common contact points among frontal impact crashes, and the side interior surface and side hardware or armrest were the more common contact points among side impact crashes. DI cases experienced more MAIS3+ injuries in the head, chest and abdominal regions and exhibited higher median ISS (q1-q3) [42 (29-62.5) vs. 17 (10-27), p < 0.0001]. While mortality was higher among occupants with DI (48% vs. 14%), this effect disappeared when adjusted by ISS. CONCLUSION: DI are associated with lateral crashes and higher ΔV. Head, chest, and abdominal injuries occur more commonly among DI patients, and the presence of these injuries rather than the DI itself is responsible for the increased mortality in these patients. LEVEL OF EVIDENCE: Epidemiologic study, level III.

Declining statewide trends in motor vehicle crashes and injury-related hospital admissions.

Numbers of crashes, rates of police-reported injury severity, and hospital admission rates were calculated for the ten year period between 2001 and 2010 in Maryland. Comparisons were made for two 5-year periods of 2001-2005 and 2006-2010. Crash characteristics remained similar for the two five-year periods, but there was a significant increase in occupant age. Declines in police-reported injury severity were noted for each of four age groups: 16-29, 30-54, 55-64, and 65+, with smaller declines among older occupants. In addition, there were significant declines in hospital admissions, comparing the two time periods. Although reductions in crashes may be attributable to various roadway, behavioral, and other safety improvement efforts, reductions in hospital admission rates most likely reflect major improvements in crashworthiness implemented during the past decade. For those admitted to hospitals, significant increases in injury severity were noted between the first and second time periods. There was an association between age and ISS, a measure of total bodily injury, with the highest ISS scores noted for the youngest and oldest groups (16-29 and 55+, respectively). In addition, there was a significant increase in the mean age over time, from 39 in 2001 to 43 in 2010, p<.001. In general, the incidence and severity of injuries increased for all body regions. There was also a significant increase in hospital mortality, although length of hospital stay remained the same. Given these trends, increased efforts need to focus on both injury prevention and treatment for the increasing population of older, sometimes frail, vehicle occupants.

Frailty and injury causation.

PURPOSE: : The current study will attempt to elucidate whether frailty has a role in motor vehicle crash injury causation. METHODS: : The association between frailty and injury was studied among Crash Injury Research Engineering Network (CIREN) cases. The baseline "physical functioning" (PF) score of the SF-36 was used as a marker of frailty (i.e., PF score <75). Frailty associations with ISS and occupant, vehicular and crash factors were explored. Frailty association with delta V was analyzed among injured (i.e., brain, rib, or femur) belted occupants in frontal crashes to establish whether frailty confers a different risk of each particular injury. RESULTS: : Frailty occurred in 13.7 % of the cohort (n=1,747). Median (q1-q3) ISS was 14.0 (10-22) among the frail and 17.0 (10-24) among the non frail (p=0.40). Frailty was significantly associated with advanced age, male gender, the presence of co-morbidities, extreme BMIs, frontal and near-side crashes and delta V < 45 km/h. Seat belt use and ISS<16 were not associated with frailty. Multiple linear regressions, adjusting for age, gender and BMI revealed a negative association between frailty and log delta V (coefficient -0.188, p=0.04) among those with rib fractures but not among those with brain injuries or femur fractures. CONCLUSION: : PF score, a marker of frailty, is associated with similar ISS and lower delta V and is independently linked to lower delta V thresholds for some injuries (i.e. rib fractures) but not for others (i.e. brain injuries and femur fractures). These associations suggest a potential role of frailty in injury causation.

Degree of urbanization and mortality from motor vehicular crashes.

PURPOSE: : The purpose of this study is to establish whether motor vehicular crash (MVC) case fatality varies across different urbanization levels in the USA using a representative sample of crashes. METHODS: : Odds ratios (ORs) and 95% confidence intervals (CIs) for the association between urbanization level [i.e., central city (CC), suburban (SU) and others (OT)] and mortality were estimated in the 1997 - 2010 National Automotive Sampling System Crashworthiness Data System. Multiple logistic regression was used to adjust for confounders. Analysis was repeated for the occurrence of pre-hospital and hospital deaths. RESULTS: : 49,040,520 weighted occupants were included in the study. The distribution of occupants by urbanization categories was: SU 45%, OT 42%, and CC 13%. Case fatality was higher among OT occupants (0.81%) than among SU (0.51%) and CC (0.37%) occupants. Similar findings were present for pre-hospital deaths (OT 0.52%, SU 0.30%, and CC 0.21%) and hospital deaths (OT 0.29%, SU 0.21%, and CC 0.16%). Multivariate analysis revealed that adjusted odds of death were higher for OT cases [OR=1.55 (1.05-2.30)] than the CC. Adjusted odds of death for SU (OR=1.05 (0.81-1.37) were not different than CCs. Similar but accentuated findings were found for pre-hospital deaths. In contrast, adjusted odds of hospital death were not different among the 3 groups. CONCLUSION: : Occupants of vehicles crashing in OT (i.e., rural areas and small cities) experience a higher likelihood of dying after MVCs than those in CC and SU. Pre-hospital deaths, not hospital deaths, are responsible for this disparity.

Crash-related mortality and model year: are newer vehicles safer?

OBJECTIVE: The objective of this study was to determine whether occupants of newer vehicles experience a lower risk of crash-related mortality. METHODS: The occurrence of death was studied in relation to vehicle model year (MY) among front seat vehicular occupants, age ≥ 16 captured in the National Automotive Sampling System Crashworthiness Data System (NASS-CDS) between 2000 and 2008. The associations between death and other occupant, vehicular and crash characteristics were also explored. Multiple logistic regression models for the prediction of death were built with model year as the independent variable and other characteristics linked to death as covariates. Imputation was used for missing data; weighted data was used. RESULTS: A total of 70,314 cases representing 30,514,372 weighted cases were available for analysis. Death occurred in 0.6% of the weighted population. Death was linked to age>60, male gender, higher BMI, near lateral direction of impact, high delta v, rollover, ejection and vehicle mismatch, and negatively associated with seatbelt use and rear and far lateral direction of impact. Mortality decreased with later model year groups (MY<94 0.78%, MY 94-97 0.53%, MY 98-04 0.51% and MY 05-08 0.38%, p=<0.0001). After adjustment for confounders, MY 94-97, MY 98-04 and MY 05-08 showed decreased odds of death [OR 0.80 (0.69-0.94), 0.82 (0.70-0.97), and 0.67 (0.47-0.96), respectively] when compared to MY <94. CONCLUSION: Newer vehicles are associated with lower crash-related mortality. Their introduction into the vehicle fleet may explain, at least in part, the decrease in mortality rates in the past two decades.

Improving trauma triage using basic crash scene data.

OBJECTIVE: to analyze the occurrence of severe injuries and deaths among crash victims transported to hospitals in relation to occupant and scene characteristics, including on-scene patient mobility, and their potential use in triaging patients to the appropriate level of care. METHODS: the occurrence of death and ISS>15 were studied in relation to occupant, crash and mobility data readily available to EMS at the scene, using weighted NASS-CDS data. Data set was randomly split in two for model development and evaluation. Characteristics were combined to develop new triage schemes. Overtriage and undertriage rates were calculated for the NASS-CDS case trauma center allocation and for the newly developed triage schemes. RESULTS: Compared to the NASS-CDS distribution, a scheme using patient mobility alone showed lower overtriage of those with ISS≤15 (38.8% vs. 55.5%) and lower undertriage of victims who died from their crash-related injuries (2.34% vs. 21.47%). Undertriage of injuries with ISS> 15 was similar (16.0 vs. 16.9). A scheme based on the presence of one of many scene risk factors (age>55, GCS<14, intrusion ≥18", near lateral impact, far lateral impact with intrusion ≥12", rollover or lack of restraint use) resulted in an undertriage of 0.86% (death) and 10.5% (ISS>15) and an overtriage of 63.4%. The combination of at least one of the scene risk factors and mobility status greatly decreased overtriage of those with ISS<15 (24.4%) with an increase in death undertriage (3.19%). Further combination of mobility and scene factors allowed for maintenance of a low undertriage (0.86%) as well as an acceptable overtriage (48%). CONCLUSION: Patient mobility data easily obtained at the scene of a crash allows triaging of injured patients to the appropriate facility with a high sensitivity and specificity. The addition of crash scene data to scene mobility allows further reductions on undertriaging or overtriaging.

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.

Are current law enforcement strategies associated with a lower risk of repeat speeding citations and crash involvement? A longitudinal study of speeding Maryland drivers.

PURPOSE: To determine whether traffic court appearances and different court verdicts were associated with risk of subsequent speeding citations and crashes. METHODS: A cohort of 29,754 Maryland drivers ticketed for speeding who either went to court or paid fines by mail in May/June 2003 was followed for 3 years. Drivers appearing in court were categorized by verdicts: 1) not guilty, 2) suspension of prosecution/no prosecution (STET/NP), 3) case dismissed, 4) probation before judgment (PBJ) and fines, or 5) fines and demerit points. Cox proportional hazard models were used to estimate adjusted hazard ratios (AHR). RESULTS: Court appearances were associated with lower risk of subsequent speeding citations (AHR = 0.92; 95% confidence interval [CI], 0.88-0.96), but higher risk of crashes (AHR = 1.25; 95% CI, 1.16-1.35). PBJ was associated with significantly lower repeat speeding tickets (AHR = 0.83; 95% CI, 0.75-0.91) and a non-significant decrease in crashes (AHR = 0.87; 95% CI, 0.75-1.02). Both repeat speeding tickets and subsequent crashes were significantly lower in the STET/NP group. CONCLUSIONS: PBJ and STET/NP may reduce speeding and crashes, but neither verdict eliminated excess crash risk among drivers who choose court appearances. Randomized, controlled evaluations of speeding countermeasures are needed to inform traffic safety policies.

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.

Impulsive or depressive personality traits do not impede behavioral change after brief alcohol interventions.

The authors investigated whether impulsivity and depression affect the success of interventions to reduce alcohol use. Unadjusted and adjusted regression models were constructed to analyze the effect of impulsivity and depression on 12-month outcomes of participants of a trauma center based randomized trial of brief personalized motivational interventions versus information and advice. Of 497 problem drinkers enrolled in the program, 248 completed the 12-month follow-up. Impulsivity, male gender, being older than 35, and intentional mechanism of injury had a direct association with drinking. After interventions, a decrease in drinking was found that was unaffected by the presence of impulsivity or depression indicators.

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.

Vehicle model year and crash outcomes: a CIREN study.

OBJECTIVE: To quantify the effect of model year (MY) on the occurrence of severe injuries and death after involvement in motor vehicle crashes. METHODS: Cases involving adult front seat occupants of vehicles MY > or = 1994 equipped with frontal airbags were selected from the Crash Injury Research and Engineering Network (CIREN) database. Cases were grouped by MY: 1994-1997, 1998-2004, and 2005-2007 (MY groups [MYG] 1, 2, and 3, respectively. MYGs were compared in relation to mortality, Injury Severity Score (ISS), and the occurrence of Abbreviated Injury Severity score (AIS) 3+ and AIS4+ injuries to each body region using Mantel Haenszel chi-square, Kruskal-Wallis, and Bonferroni corrected t test. To adjust for confounders, multiple logistic regression models were built to explore the association of MYG with death. Covariates included age, BMI, delta v, principal direction of force (PDOF), restraint use, and vehicle type. RESULTS: A total of 1888 cases was distributed within MYG1 (34%), MYG2 (62%), and MYG (34%). Age, gender, BMI, and PDOF distribution did not differ among MYGs. Though ISS distribution was not different, a decrease in the occurrence of AIS4+ of the thorax and spine regions was noted over time. Mortality also decreased over time (18, 9, and 4% MYG 1, 2, and 3, respectively). Multivariate analysis revealed a protective effect of MYG2 and MGY3 (odds ratio [OR], 0.57 [0.44-0.75] and 0.22 [0.07-0.50], respectively) in relation to death. CONCLUSIONS: Front seat occupants of later MY vehicles injured during crashes experience a decreased likelihood of very severe thoracic injuries, spinal injuries, and death.

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.

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.

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.