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.

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.

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.

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.

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.

Crash culpability relative to age and sex for injured drivers using alcohol, marijuana or cocaine.

While there is a great deal of data documenting the etiologic role alcohol use plays in crash culpability, there is a dearth of data for other drugs. The purpose of this study was to assess crash culpability for single drug use among injured drivers admitted to a regional trauma center. This study is the largest of its kind involving trauma center patients. Clinical toxicology results obtained for patient care were linked to police crash reports containing a field attributing crash culpability. Drugs studied were alcohol, cocaine, and marijuana. As expected crash culpability was strongly associated with pre-crash alcohol use. In contrast, for both men and women, this study did not find an association between crash culpability and marijuana use. The data documents a significant association between cocaine use and crash culpability for both sexes and for drivers 21 to 40 years of age. This is the first large study to assess for crash culpability among injured drivers relative to cocaine use. Each year approximately 42 to 43,000 people die annually as the result of vehicular crashes. (NHTSA, 2005) For the decade 1994 through 2003, alcohol was a factor in 40-43% fatal injury crashes - the fatally injured person being either a vehicular occupant or pedestrian. Specifically 25 to 29% of drivers of cars and light trucks involved in those crashes were alcohol positive. Further, it is estimated that 80% or more of those drivers had blood alcohol concentrations (BAC) of 80 mg/dl or greater. (NHTSA, 2005).

Psychosocial and physical factors associated with lower extremity injury.

With the increasing availability of modern occupant restraints, more drivers and passengers are surviving high-energy crashes. However, a large number, especially those involved in frontal and offset frontal crashes, incur disabling lower extremity injuries. In the past, not much attention was paid to these injuries, as they were usually not life threatening. Despite the low AIS scores associated with injuries to the lower extremities, they pose a major physical and psychological burden on patients' and their ability to return to pre-crash functioning. Associated injuries, such as mild brain injuries, and psychosocial factors such as depression, also influence the long-term outcome.

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.

Pursuit of Licensure by Senior Drivers Referred by Police to a State Licensing Agency's Medical Advisory Board.

In all fifty United States and the District of Columbia, police Requests for Re-examination (RRE) concerning fitness to driver are accepted by licensing agencies. This study assessed licensing outcomes of senior drivers, ≥75 years of age, who had RREs submitted to the Medical Advisory Board (MAB) of a Maryland Motor Vehicle Administration from March 2005 through April 2007. RRE traffic event information (including crashed, did not crash), driver demographic information, initial MAB recommendations (suspension vs no suspension), driving occupational therapists assessments, and drivers' pursuit of continued licensure were entered into a database. During the period of study, 475 RREs were referred to the MAB. The percent of referred senior drivers (n=240, 50.4%) was similar to that of younger drivers (n=235, 49.5%). A higher percentage of senior drivers retired from driving compared to younger drivers; being, 57.1% vs 23.8% (p <.01), respectively. Further analyses limited to the 240 senior drivers found: 139 (57.9%) were men, 150 (62.5%) were 75-84 years of age, 119 (49.5%) were noted to be disoriented at the traffic scene, 141 (58.8%) were involved in a crash, and 127 (52.9%) were initially suspended as the result of MAB review. The following factors were significantly related to retiring from driving, initial MAB suspension and greater age. Of the 127 drivers who were initially suspended, 82 (64.6%) retired from driving, and 45 (35.4%) pursued further licensure (p <0.01). In contrast, the percentage of non-suspended drivers who did or did not pursue further licensure was similar; being 48.7% vs 51.3%. Among drivers ≥85 years of age, 68.9% retired from driving, compared with 50% of the drivers who were 75 to 84 years of age (p <0.01) While not statisically significant, higher percentages of driving retirement were noted for the following: sex - a greater percentage of men compared to women (61.9% vs 49.5%); confusion at the traffic scene (confused, 57.1% vs non-confused, 42.9%); and crash involvement (56.7% who crashed, retired vs 43.3% of those who did not crash, retired). Overall, the most important finding of this study is that as a result of police referral, only one-fifth (20.4%) of senior drivers 75 years of age or older, continued to maintain their driving privilege. However, only 40 drivers (16.7%) retained their original driving privilege without added restrictions. The data suggest that senior drivers who are not medically fit to drive may be identified by police referrals to a licensing agency. Driving occupational therapy assessments and training, and additional driving restrictions are recommended to facilitate continuation of the driving privilege for some drivers.

Police referral of drivers to the Maryland Motor Vehicle Administration's Medical Advisory Board.

In the 50 United States and the District of Columbia law enforcement medical referrals are accepted by licensing agencies. This study assessed driving actions, medical concerns, and medical conditions in 486 police referrals to the Medical Advisory Board of the Maryland Motor Vehicle Administration during a 25-month period. Driving actions, medical concerns, and medical conditions were grouped into categories and entered into a database. These elements were analyzed relative to driver age and sex. In addition, the issuance of citations for driving violations was studied relative to age and sex. A greater percentage of drivers 60 years of age or greater (senior adults) were referred compared to the general population of licensed drivers that age, being 71.4% vs 20.6% (p <0.01). Crashing, the most common driving action, was not associated with age or sex. Among driving actions frequently mentioned relative to older drivers, only confusion of pedals was associated with senior adults drivers as compared to younger drivers (6.1% vs 0.1%, p <0.01). Of the most frequently mentioned medical concerns, confusion/disorientation was associated with being a senior adult (p <0.01), while loss of consciousness was associated with younger drivers (p <0.01). The most frequently mentioned medical conditions, diabetes and seizure, were associated with being under 60 years of age. All mentions of dementia were in senior adult drivers. Compared with younger drivers, drivers 60 years of age or older, were less often summoned for driving violations, being 33.0% vs 53.5% (p <0.01), respectively. The threshold for the issuance of fewer citations was lower for men (40 to 59 years of age) compared to women (60 years of age or greater). Studies are needed to correlate specific traffic violations and/or crashes to specific medical conditions.

Risk factors associated with pelvic fractures sustained in motor vehicle collisions involving newer vehicles.

BACKGROUND: Despite advances in automotive safety, pelvic fractures caused by motor vehicle collisions remain a significant cause of mortality, morbidity, and functional disability. This study was designed to evaluate epidemiologic and biomechanic risk factors associated with pelvic fractures resulting from motor vehicle collisions. We utilized the Crash Injury Research Engineering Network (CIREN) database to identify these risk factors in newer vehicles. METHODS: Data were prospectively collected at the ten CIREN centers from 1996 to 2005. Specific data were then abstracted on all patients, biomechanic crash characteristics, and injuries sustained. Patients involved in a frontal or near-side lateral impact with pelvic fractures were compared with those without. Univariate analysis was performed using a chi2 analysis. Logistic regression was used to identify significant risk factors in a multivariate analysis to control for confounding associations. RESULTS: Of the 1,851 patients studied, 511 (27.6%) had a pelvic fracture. The overall mortality was 17%. Injury specific factors associated with pelvic fracture were higher Injury Severity Score (ISS) and fatality of the patient. Biomechanic factors associated with the risk of pelvic fracture included; no airbag deployment (p < 0.001), smaller vehicle (p = 0.05), and lateral deformation location (p < 0.001). When stratified by vehicle deformation location, logistic regression models revealed statically significant variables in a frontal impact which included; higher body mass index, higher ISS, large patient vehicle, no seatbelt use, and higher deltaV. For near-side lateral impacts, multivariate analysis revealed statistically significant variables of lower body mass index, higher ISS, female sex, small vehicle size, and higher deltaV. CONCLUSIONS: Even in newer vehicles with federally mandated safety features, pelvic fractures remain a common injury. Pelvic fractures may serve as a marker of crash severity and specific crash characteristics are associated with pelvic fractures. Lateral crashes are significantly more likely to result in a pelvic fracture and, therefore, prevention of pelvic fractures should focus on improving occupant safety in near-side lateral impacts. Recognition of other associations should lead researchers to further investigate causative factors that will ultimately result in improved vehicle design.

Life-altering outcomes after lower extremity injury sustained in motor vehicle crashes.

BACKGROUND: Lower extremity injuries (LEIs) sustained in vehicular crashes result in physical problems and unexpected psychosocial consequences. Their significance is diminished by low Abbreviated Injury Scale scores. METHODS: Drivers who sustained LEIs were identified as part of the Crash Injury Research and Engineering Network (CIREN) and interviewed during hospitalization, at 6 months, and at 1 year. All were occupants of newer vehicles with seatbelts and airbags. RESULTS: Sixty-five patients were followed for 1 year. Injuries included mild brain injury (43%), ankle/foot fractures (55%), and bilateral injuries (37%). One year post-injury, 46% reported limitations in walking and 22% with ankle/foot fractures were unable to return to work. Depression (39%), cognitive problems (32%), and post-traumatic stress disorder (18%) were significant in the mild brain injury group. CONCLUSIONS: Long-lasting physical and psychological burdens may impede recovery and alter the lifestyle of patients with LEI. These issues need to be addressed by trauma center personnel.