Occupants In Motor Vehicle Crashes Research Articles

Surgical Fasciotomies for Pediatric Acute Compartment Syndrome, and Overview

Introduction: The goal of treatment is firstly to save the patient's life and secondly to save the damaged climb. Fasciectomy is the only accepted treatment for compartment syndrome and should be performed promptly after the diagnosis is made. The results after fasciectomy are best when there is no delay in treatment. Method: Clinically determined according to the "5 P's" and measured Intracompartmental Pressure (ICP) with P ≥ 30 mmHg. Perform traditional Fasciotomies surgery on all patients. Results: There were four patients; Mean age: 54 months ± 31.749; Girl: 03; Boy: 01; Fall from hight: 2; Sport trauma: 01; Pedestrian in a car accident: 01; Mean - Intracompartmental Pressure (ICP): 53.75 mmHg.The most common mechanisms of injury are pedestrians struck by motor vehicles, falls, sports, and vehicle occupants in motor vehicle crashes. Forearm fractures are the most common cause in the upper extremity, and fractures of the tibia and/or fibula are most common in the lower extremity. Conclusions: Fractures significantly increase the risk of developing compartment syndrome in both forearm and leg fractures. The patients were transferred directly from the emergency room to the operating room, suggesting that the remaining developed compartment syndrome after admission or late diagnosis.

Computed tomography assessment of pelvic bone density: Associations with age and pelvic fracture in motor vehicle crashes

Motor vehicle crash (MVC) occupants routinely get a computed tomography (CT) scan to screen for internal injury, and this CT can be leveraged to opportunistically derive bone mineral density (BMD). This study aimed to develop and validate a method to measure pelvic BMD in CT scans without a phantom, and examine associations of pelvic BMD with age and pelvic fracture incidence in seriously injured MVC occupants from the Crash Injury Research and Engineering Network (CIREN) study. A phantom-less muscle-fat calibration technique to measure pelvic BMD was validated using 45 quantitative CT scans with a bone calibration phantom. The technique was then used to measure pelvic BMD from CT scans of 252 CIREN occupants (ages 16+) in frontal MVCs who had sustained either abdominal or pelvic injury. Pelvic BMD was analyzed in relation to age and pelvic fracture incidence. In the validation set, phantom-based calibration vs. phantom-less muscle-fat calibration yielded similar BMD values at the anterior superior iliac spine (ASIS; R2 = 0.95, p < 0.001) and iliac crest (R2 = 0.90, p < 0.001). Pelvic BMD was measured in 150 female and 102 male CIREN occupants aged 16–89, and 25% of these occupants sustained pelvic fracture. BMD at the ASIS and iliac crest declined with age (p < 0.001). For instance, iliac crest BMD decreased an average of 25 mg/cm3 per decade of age. The rate of iliac crest BMD decline was 7.6 mg/cm3 more per decade of age in occupants with pelvic fracture compared to those not sustaining pelvic fracture. Findings suggest pelvic BMD may be a contributing risk factor for pelvic fracture in MVCs.

Effects of muscle quantity and bone mineral density on injury and outcomes in older adult motor vehicle crash occupants

Objectives: Quantify the independent and combined effects of abdominal muscle quantity and lumbar bone mineral density (BMD) on injury risk and in-hospital outcomes in severely injured motor vehicle crash (MVC) occupants ages 50 and older. Methods: Skeletal muscle area measurements of MVC occupants were obtained through semi-automated segmentation of an axial computed tomography (CT) slice at the L3 vertebra. An occupant height-normalized Skeletal Muscle Index (SMI) was calculated - a defining metric of sarcopenia and low muscle mass (sarcopenia thresholds: <38.5 cm2/m2 females; <52.4 cm2/m2 males). Lumbar BMD was obtained using a validated, phantomless CT calibration method (osteopenia threshold: <145 mg/cm3). SMI and BMD values were used to categorize occupants, and logistic regression was used to associate sarcopenia, osteopenia, and osteosarcopenia predictors to injury outcomes (e.g., Injury Severity Score (ISS), maximum Abbreviated Injury Scale (MAIS) score, fractures) and hospital outcomes (e.g., length of stay, ICU days). Results: Of the 336 occupants, 210 (63%) were female (mean ± SD: age 66.3 ± 10.6). SMI was 41.7 ± 8.0 cm2/m2 in females and 51.2 ± 10.8 cm2/m2 in males. Based on SMI, 40% of females and 55% of males were classified as sarcopenic. BMD was 163.2 ± 38.3 mg/cm3 in females and 164.1 ± 35.4 mg/cm3 in males, with 41% of females and 33% of males classified as osteopenic. Prevalence of both conditions (osteosarcopenia) was similar between females (21%) and males (22%). Incidence of low SMI and BMD increased with age. Sarcopenic individuals were less likely to sustain a MAIS 2+ thorax injury and had longer ICU stays. Osteopenic individuals were more likely to sustain upper extremity injuries and fractures, and were less likely to be discharged to a rehabilitation facility. Osteosarcopenic individuals were less likely to be ventilated or admitted to the ICU but tended to spend more time on the ventilator if placed on one. Conclusions: Osteosarcopenia was not associated with any injury outcomes, but sarcopenia was associated with thoracic injury and osteopenia was associated with upper extremity injury incidence. Sarcopenia was only associated with ICU length of stay, while osteopenia was only associated with discharge destination. Osteosarcopenia was associated with likelihood of being ventilated, being admitted to the ICU, and with increased length of ventilation.

Age-based differences in the disability of spine injuries in pediatric and adult motor vehicle crash occupants

Objective The objective was to develop a disability-based metric for quantifying disability rates as a result of motor vehicle crash (MVC) spine injuries and compare functional outcomes between pediatric and adult subgroups. Methods Disability rate was quantified using Functional Independence Measure (FIM) scores within the National Trauma Data Bank—Research Data System for the top 95% most frequent Abbreviated Injury Scale (AIS) 3 spine injuries (14 unique injuries). Pediatric (7–18 years), young adult (19–45 years), middle-aged adult (46–65 years), and older adult (66+ years) MVC occupants with FIM scores available and at least one of the 14 spine injuries were included. FIM scores of 1 or 2 at time of discharge were used to define disability and correspond to full functional or modified dependence in self-feeding, locomotion, and/or verbal expression. Disability rate was evaluated on a per injury basis for each AIS 3 spine injury and calculated as the proportion of cases associated with disability (i.e. FIM of 1 or 2) out of the total cases of that particular injury. Disability rates were calculated with and without the exclusion of cases with severe co-injuries (AIS 4+) to minimize bias from additional non-spinal injuries that could have contributed to disability. Associations between adjusted disability rates and existing mortality rates were investigated. Results Locomotion impairment alone was the most frequent disability type for the top 14 AIS 3 spine injuries (7 cervical, 4 thoracic, and 3 lumbar) across all age groups and spine regions. Adjusted and unadjusted disability rates ranged from 0-69%. Adjusted disability rates increased with age: 14.8 ± 10% (mean ± SD) in pediatrics to 16.2 ± 6.6% (young adults), 29.2 ± 10.9% (middle-aged adults), and 45.0 ± 12.2% (older adults). Among all adult populations, adjusted mortality and disability rates were positively correlated (R 2>0.24), with disability rates consistently greater than corresponding mortality rates. Conclusions Older adults had significantly greater disability rates associated with MVC spine injuries across all spinal regions. MVC disability rates for pediatrics were considerably lower. Overall, rates of mortality were significantly lower than rates of disability. The adjusted disability rates developed can supplement existing injury metrics by accounting for age- and location-specific functional implications of MVC spine injuries.

Cluster analysis of seriously injured occupants in motor vehicle crashes

Permanent monitoring of real-world crashes is important to identify injury patterns and injury mechanisms that still occur in the field despite existing regulations and consumer testing programs. This study investigates current injury patterns at the MAIS 3+ level in the accident environment without limiting the impact direction. The approach consisted of applying unsupervised clustering algorithms to NASS-CDS crash data in order to classify seriously injured, belted occupants into clusters based on injured body regions, biomechanical characteristics and crash severity. Injury patterns in each cluster were analyzed and associated with other characteristics of the crash, such as the collision configuration. The groups of seriously injured occupants found in this research contain a large amount of information and research possibilities. The resulting clusters represent new opportunities for vehicle safety, which have been highlighted in this study.

Injury risk curves in far-side lateral motor vehicle crashes by AIS level, body region and injury code

Objective The objective of this study was to develop injury risk curves as a function of change in vehicle velocity for occupants in far-side lateral motor vehicle crashes (MVCs) by AIS level, body region, and specific AIS codes that commonly occur in this crash mode. Methods The National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) years 2000–2015 database was queried, resulting in 4,495 non-weighted far-side crashes. For each case, occupant age, sex, and the following metadata were collected: vehicle model year, vehicle body type, lateral delta-v, normalized PDOF, multiple impacts, belt use, seat position, object contacted, striking vehicle body type, maximum crush extent and side airbag deployment. Multivariable logistic regression was used to develop risk curves for AIS 2+ through 5+ injuries, AIS 2+ injuries by body region (head, thorax, lower extremity), and for each of the 10 most frequent far-side AIS 2+ injuries. Significant covariates were determined by backwards elimination (p < 0.05). The full dataset and a subsampled dataset of only cases with side airbag deployment were used to develop risk curves. Results For AIS 2+ through 5+ injury, greater delta-V was associated with greater injury risk (OR’s: 2.48–3.66 per 11.9 kph increase) and belt use was associated with lower risk (OR’s: 0.04–0.36 compared to unbelted). Multiple impacts were significant predictors of increased AIS 3+, 4+ and 5+ injury risk (OR’s: 2.56, 2.27 and 2.83 compared to single impact). For AIS 2+ body region injuries, lateral delta-V and maximum CDC extent were positively associated with increased head, thorax and lower extremity injury risk while belt use was associated with lower risk. Increased lateral delta-v, unbelted status, and greater maximum CDC extent frequently increased injury risk for the most common far-side injuries. Side airbag deployment was not a significant covariate for the injury risk models. Conclusions The resulting risk models expand upon previous literature gaps to provide a more comprehensive view of contributors to injury risk for occupants in far-side MVCs. This study yields risk curves based on the latest available NASS-CDS data.

Sarcopenia and osteosarcopenia in seriously injured motor vehicle crash occupants

Objective: The objective of this study was to examine the prevalence of sarcopenia (low muscle mass) and osteosarcopenia (low bone density and muscle mass) in older motor vehicle crash (MVC) occupants and the relationship of these musculoskeletal conditions with age, sex, and injury.Methods: Sarcopenia and osteopenia was assessed from abdominal computed tomography (CT) scans of 61 seriously injured MVC occupants over age 50 in the Crash Injury Research and Engineering Network (CIREN) database.Results: The prevalence was 43% for sarcopenia, 25% for osteopenia, and 15% for osteosarcopenia in the CIREN occupants. The Injury Severity Score (ISS) was higher in those with only sarcopenia (mean ± SE = 22.4 ± 2.3), followed by those with osteosarcopenia (17.9 ± 2.4) and only osteopenia (12.8 ± 1.5). More total fractures were observed in occupants with sarcopenia alone (7.6 ± 1.5) or osteosarcopenia (7.0 ± 2.1) compared to nonsarcopenic occupants with osteopenia (4.0 ± 2.5).Conclusions: Sarcopenia and osteosarcopenia may be associated with more serious injuries and fractures in MVCs.

Age-based differences in the disability of extremity injuries in pediatric and adult occupants

Objective: The objective was to develop a disability-based metric for motor vehicle crash (MVC) upper and lower extremity injuries and compare functional outcomes between children and adults.Methods: Disability risk (DR) was quantified using Functional Independence Measure (FIM) scores within the National Trauma Data Bank–Research Data System for the top 95% most frequently occurring Abbreviated Injury Scale (AIS) 3 extremity injuries (22 unique injuries). Pediatric (7–18 years), young adult (19–45 years), middle-aged (46–65 years), and older adult (66+ years) MVC occupants with an FIM score and at least one of the 22 extremity injuries were included. DR was calculated for each injury as the proportion of occupants who were disabled of those sustaining the injury. A maximum AIS-adjusted disability risk (DRMAIS) was also calculated for each injury, excluding occupants with AIS 4+ co-injuries.Results: Locomotion impairment was the most frequent disability type across all ages. DR and DRMAIS of the extremity injuries ranged from 0.06 to 1.00 (6%–100% disability risk). Disability risk increased with age, with DRMAIS increasing from 25.9% ± 8.6% (mean ± SD) in pediatric subjects to 30.4% ± 6.3% in young adults, 39.5% ± 6.6% in middle-aged adults, and 60.5 ± 13.3% in older adults. DRMAIS for upper extremity fractures differed significantly between age groups, with higher disability in older adults, followed by middle-aged adults. DRMAIS for pelvis, hip, shaft, knee, and other lower extremity fractures differed significantly between age groups, with older adult DRMAIS being significantly higher for each fracture type. DRMAIS for hip and lower extremity shaft fractures was also significantly higher in middle-aged occupants compared to pediatric and young adult occupants. The maximum AIS-adjusted mortality risk (MRMAIS, proportion of fatalities among occupants sustaining an MAIS 3 injury) was not correlated with DRMAIS for extremity injuries in pediatric, young adult, middle-aged, and older adult occupants (all R2 < 0.01). Disability associated with each extremity injury was higher than mortality risk.Conclusions: Older adults had significantly greater disability for MVC extremity injuries. Lower disability rates in children may stem from their increased physiological capacity for bone healing and relative lack of bone disease. The disability metrics developed can supplement AIS and other severity-based metrics by accounting for the age-specific functional implications of MVC extremity injuries.

The need to improve information on road user type in National Vital Statistics System mortality data

Objectives: Both the National Vital Statistics System (NVSS) and the Fatality Analysis Reporting System (FARS) can be used to examine motor vehicle crash (MVC) deaths. These 2 data systems operate independently, using different methods to collect and code information about the type of vehicle (e.g., car, truck, bus) and road user (e.g., occupant, motorcyclist, pedestrian) involved in an MVC. A substantial proportion of MVC deaths in NVSS are coded as “unspecified” road user, which reduces the utility of the NVSS data for describing burden and identifying prevention measures. This study aimed to describe characteristics of unspecified road user deaths in NVSS to further our understanding of how these groups may be similar to occupant road user deaths.Methods: Using data from 1999 to 2015, we compared NVSS and FARS MVC death counts by road user type, overall and by age group, gender, and year. In addition, we examined factors associated with the categorization of an MVC death as unspecified road user such as state of residence of decedent, type of medical death investigation system, and place of death.Results: The number of MVC occupant deaths in NVSS was smaller than that in FARS in each year and the number of unspecified road user deaths in NVSS was greater than that in FARS. The sum of the number of occupant and unspecified road user deaths in NVSS, however, was approximately equal to the number of FARS occupant deaths. Age group and gender distributions were roughly equivalent for NVSS and FARS occupants and NVSS unspecified road users. Within NVSS, the number of MVC deaths listed as unspecified road user varied across states and over time. Other categories of road users (motorcyclists, pedal cyclists, and pedestrians) were consistent when comparing NVSS and FARS.Conclusions: Our findings suggest that the unspecified road user MVC deaths in NVSS look similar to those of MVC occupants according to selected characteristics. Additional study is needed to identify documentation and reporting challenges in individual states and over time and to identify opportunities for improvement in the coding of road user type in NVSS.

Accident analysis to support the development of strategies for the prevention of brain injuries in car crashes

This study estimated the frequency and risk of Moderate-to-Maximal traumatic brain injuries sustained by occupants in motor vehicle crashes in the US. National Automotive Sampling System - Crashworthiness Data System crashes that occurred in years 2001–2015 with light vehicles produced 2001 or later were incorporated in the study. Crash type, crash severity, car model year, belt usage and occupant age and sex were controlled for in the analysis. The results showed that Moderate concussions account for 79% of all MAISbrain2+ injuries. Belted occupants were at lower risks than unbelted occupants for most brain injury categories, including concussions. After controlling for the effects of age and crash severity, belted female occupants involved in frontal crashes were estimated to be 1.5 times more likely to sustain a concussion than male occupants in similar conditions. Belted elderly occupants were found to be at 10.5 and 8 times higher risks for sub-dural haemorrhages than non-elderly belted occupants in frontal and side crashes, respectively. Adopted occupant protection strategies appear to be insufficient to achieve significant decreases in risk of both life-threatening brain injuries and concussions for all car occupants. Further effort to develop occupant and injury specific strategies for the prevention of brain injuries are needed. This study suggests that these strategies may consider prioritization of life-threatening brain vasculature injuries, particularly in elderly occupants, and concussion injuries, particularly in female occupants.

Functional outcomes of thoracic injuries in pediatric and adult occupants

ABSTRACTObjective: To develop a disability metric for motor vehicle crash (MVC) thoracic injuries and compare functional outcomes between pediatric and adult populations.Methods: Disability risk (DR) was quantified using Functional Independence Measure (FIM) scores within the National Trauma Data Bank (NTDB) for the top 95% most frequently occurring AIS 2, 3, 4, and 5 thoracic injuries in NASS-CDS 2000–2011. The NTDB contains a truncated form of the FIM score, including three items (self-feed, locomotion, and verbal expression), each graded from full functional dependence to full functional independence. Pediatric (ages 7–18 years), adult (19–45), middle-aged adult (46–65), and older adult (66+) MVC occupants were classified as disabled or not disabled based on the FIM scale. The DR was calculated for each injury within each age group by dividing the number of patients who were disabled that sustained the specific injury by the number of patients who sustained the specific injury. To account for the impact of more severe co-injuries, a maximum Abbreviated Injury Scale (MAIS) adjusted DR (DRMAIS) was also calculated. DR and DRMAIS could range from 0 (0% disability risk) to 1 (100% disability risk).Results: The mean DRMAIS for MVC thoracic injuries was 20% for pediatric occupants, 22% for adults, 29% for middle-aged adults, and 43% for older adults. Older adults possessed higher DRMAIS values for diaphragm laceration/rupture, heart laceration, hemo/pneumothorax, lung contusion/laceration, rib fracture, and sternum fracture compared to the other age groups. The pediatric population possessed a higher DRMAIS value for flail chest compared to the other age groups.Conclusions: Older adults had significantly greater overall disability than each of the other age groups for thoracic injuries. The developed disability metrics are important in quantifying the significant burden of injuries and loss of quality life years. Such metrics can be used to better characterize severity of injury and further the understanding of age-related differences in injury outcomes, which can impact future age-specific modifications to AIS.

Disability risk in pediatric motor vehicle crash occupants.

Mortality rates among children in motor vehicle crashes (MVCs) are typically low; however, nonfatal injuries can vary in severity by imposing differing levels of short- and long-term disability. To better discriminate the severity of nonfatal MVC injuries, a pediatric-specific disability risk (DR) metric was created. The National Automotive Sampling System 2000 to 2011 was used to define the top 95% most common Abbreviated Injury Scale (AIS) 2+ injuries among pediatric MVC occupants. Functional Independence Measure scores were abstracted from the National Trauma Data Bank 2002 to 2006. Multiple imputation was used to account for missing data. The DR and coinjury-adjusted DR (DRMAIS) of the most common AIS 2+ MVC-induced injuries were calculated for 7-year-old to 18-year-old children by determining the proportion of those disabled after an injury to those sustaining the injury. DR and DRMAIS values ranged from 0 to 1, representing 0% to 100% DR. The mean DR and DRMAIS of all injuries were 0.290 and 0.191, respectively. DR and DRMAIS were greatest for injuries to the head (DR, 0.340; DRMAIS, 0.279), thorax (DR, 0.320; DRMAIS, 0.233), and spine (DR, 0.315; DRMAIS, 0.200). The mean DR and DRMAIS increased with increasing AIS severity but there was significant variation and overlapping values across AIS severity levels. Comparison of DRMAIS to coinjury-adjusted mortality risk (MRMAIS) revealed that among 118 injuries with MRMAIS of 0.000, DRMAIS ranged from 0.000 to 0.429. Incorporation of DR metrics into injury severity metrics may improve the ability to distinguish between the severity of different nonfatal injuries. This is especially crucial in the pediatric population where permanent disability can result in a high number of years lost due to disability. The accuracy of such severity metrics is crucial to the success of pediatric triage algorithms such as Advanced Automatic Crash Notification algorithms. Epidemiologic/prognostic study, level III.

Head injuries (TBI) to adults and children in motor vehicle crashes

ABSTRACTPurpose: This is a descriptive study. It determined the annual, national incidence of head injuries (traumatic brain injury, TBI) to adults and children in motor vehicle crashes. It evaluated NASS-CDS for exposure and incidence of various head injuries in towaway crashes. It evaluated 3 health databases for emergency department (ED) visits, hospitalizations, and deaths due to TBI in motor vehicle occupants.Methods: Four databases were evaluated using 1997–2010 data on adult (15+ years old) and child (0–14 years old) occupants in motor vehicle crashes: (1) NASS-CDS estimated the annual incidence of various head injuries and outcomes in towaway crashes, (2) National Hospital Ambulatory Medical Care Survey (NHAMCS)-estimated ED visits for TBI, (3) National Hospital Discharge Survey (NHDS) estimated hospitalizations for TBI, and (4) National Vital Statistics System (NVSS) estimated TBI deaths. The 4 databases provide annual national totals for TBI related injury and death in motor vehicle crashes based on differing definitions with TBI coded by the Abbreviated Injury Scale (AIS) in NASS-CDS and by International Classification of Diseases (ICD) in the health data.Results: Adults: NASS-CDS had 16,980 ± 2,411 (risk = 0.43 ± 0.06%) with severe head injury (AIS 4+) out of 3,930,543 exposed adults in towaway crashes annually. There were 49,881 ± 9,729 (risk = 1.27 ± 0.25%) hospitalized with AIS 2+ head injury, without death. There were 6,753 ± 882 (risk = 0.17 ± 0.02%) fatalities with a head injury cause. The public health data had 89,331 ± 6,870 ED visits, 33,598 ± 1,052 hospitalizations, and 6,682 ± 22 deaths with TBI. NASS-CDS estimated 48% more hospitalized with AIS 2+ head injury without death than NHDS occupants hospitalized with TBI. NASS-CDS estimated 29% more deaths with AIS 3+ head injury than NVSS occupant TBI deaths but only 1% more deaths with a head injury cause. Children: NASS-CDS had 1,453 ± 318 (risk = 0.32 ± 0.07%) with severe head injury (AIS 4+) out of 454,973 exposed children annually. There were 2,581 ± 683 (risk = 0.57 ± 0.15%) hospitalized with AIS 2+ head injury, without death. There were 466 ± 132 (risk = 0.10 ± 0.03%) fatalities with a head injury cause. The public health data had 19,251 ± 2,803 ED visits, 3,363 ± 255 hospitalizations, and 488 ± 6 deaths with TBI. NASS-CDS estimated 24% fewer hospitalized children with AIS 2+ head injury without death than NHDS hospitalization with TBI. NASS-CDS estimated 31% more deaths with AIS 3+ head injury than NVSS child deaths but 5% fewer deaths with a head injury cause.Conclusions: The annual national incidence of motor vehicle–related head injury (TBI) was estimated using 1997–2010 NASS-CDS from the Department of Transportation and NHAMCS (ED visits), NHDS (hospitalizations), and NVSS (deaths) from the Department of Health and Human Services. The transportation and health databases use different definitions and coding, which complicates direct comparisons. Future work is needed where ICD to AIS translators are used if comparisons of serious head injuries in NASS and health data sets are to be made.

Investigation of Intraventricular Hemorrhage Volume in Motor Vehicle Crash Occupants

Motor vehicle crashes (MVCs) are a leading cause of traumatic intracranial injuries which often have devastating impacts on morbidity and mortality. Intraventricular hemorrhage (IVH) is one type of head injury that is identified on post-traumatic computed tomography (CT) scans.

Mortality Risk in Pediatric Motor Vehicle Crash Occupants: Accounting for Developmental Stage and Challenging Abbreviated Injury Scale Metrics

Objective: Survival risk ratios (SRRs) and their probabilistic counterpart, mortality risk ratios (MRRs), have been shown to be at odds with Abbreviated Injury Scale (AIS) severity scores for particular injuries in adults. SRRs have been validated for pediatrics but have not been studied within the context of pediatric age stratifications. We hypothesized that children with similar motor vehicle crash (MVC) injuries may have different mortality risks (MR) based upon developmental stage and that these MRs may not correlate with AIS severity.Methods: The NASS-CDS 2000–2011 was used to define the top 95% most common AIS 2+ injuries among MVC occupants in 4 age groups: 0–4, 5–9, 10–14, and 15–18 years. Next, the National Trauma Databank 2002–2011 was used to calculate the MR (proportion of those dying with an injury to those sustaining the injury) and the co-injury-adjusted MR (MRMAIS) for each injury within 6 age groups: 0–4, 5–9, 10–14, 15–18, 0–18, and 19+ years. MR differences were evaluated between age groups aggregately, between age groups based upon anatomic injury patterns and between age groups on an individual injury level using nonparametric Wilcoxon tests and chi-square or Fisher's exact tests as appropriate. Correlation between AIS and MR within each age group was also evaluated.Results: MR and MRMAIS distributions of the most common AIS 2+ injuries were right skewed. Aggregate MR of these most common injuries varied between the age groups, with 5- to 9-year-old and 10- to 14-year-old children having the lowest MRs and 0- to 4-year-old and 15- to 18-year-old children and adults having the highest MRs (all P <.05). Head and thoracic injuries imparted the greatest mortality risk in all age groups with median MRMAIS ranging from 0 to 6% and 0 to 4.5%, respectively. Injuries to particular body regions also varied with respect to MR based upon age. For example, thoracic injuries in adults had significantly higher MRMAIS than such injuries among 5- to 9-year-olds and 10- to 14-year-olds (P =.04; P <.01). Furthermore, though AIS was positively correlated with MR within each age group, less correlation was seen for children than for adults. Large MR variations were seen within each AIS grade, with some lower AIS severity injuries demonstrating greater MRs than higher AIS severity injuries. As an example, MRMAIS in 0- to 18-year-olds was 0.4% for an AIS 3 radius fracture versus 1.4% for an AIS 2 vault fracture.Conclusions: Trauma severity metrics are important for outcome prediction models and can be used in pediatric triage algorithms and other injury research. Trauma severity may vary for similar injuries based upon developmental stage, and this difference should be reflected in severity metrics. The MR-based data-driven determination of injury severity in pediatric occupants of different age cohorts provides a supplement or an alternative to AIS severity classification for pediatric occupants in MVCs.

Factors Associated With Clinically Significant Head Injury in Children Involved in Motor Vehicle Crashes

Objective: Head injury is the most common cause of death for child occupants in motor vehicle crashes (MVCs). The morbidity associated with nonlethal MVC-related head injuries is of great clinical consequence as well. The purpose of this study was to identify the frequency of, and risk factors for, clinically significant head injury (CSHI) in child occupants in MVCs. Methods: A large, child-specific crash surveillance system linking insurance claims data to telephone survey data was utilized. Qualifying crashes involved model year 1990 or newer vehicles in crashes with one or more child occupants (age 4 to 15 years) occurring in 15 U.S. states. Data were accrued between March 2000 and December 2007. A probability sample of crashes was selected for telephone survey with the driver of the insured vehicle. A clinically significant head injury, as reported by the child's parent using a validated survey, included concussions, skull fractures, and intracranial hemorrhages. Multivariate logistic regression was used to identify factors associated with a CSHI. Results: During the period of study, completed interviews were obtained on 19,075 children aged 4–15, representing 318,527 children involved in 219,511 crashes. The overall rate of CSHI in child occupants was 1.08 percent. Factors associated with an increased risk of head injury included rollover (odds ratio [OR] = 8.60, 95% confidence interval [CI] 6.40–11.57) and near-side impact crashes (OR = 2.39, 95% CI 1.73–3.30) vs. frontal impact; lack of restraint (OR = 3.13, 95% CI 2.26–4.33) vs. restrained; and driver age < 25 years (OR = 1.43, 95% CI 1.12–1.81) vs. driver age ⩾ 25 years. Some factors varied based on occupant age, and younger child age had a protective effect on the risk for head injury. Conclusion: The risk of CSHI for 4- to 15-year-old child occupants was 1.08 percent. Several demographic and crash factors were associated with CSHI in child occupants. This information may help inform design safety initiatives.

Effects of osteoporosis on AIS 3+ injury risk in motor-vehicle crashes

Older occupants in motor-vehicle crashes are more likely to experience injury than younger occupants. One possible reason for this is that increasing age is associated with increased prevalence of osteoporosis, which decreases bone strength. Crash-injury data were used with Bayes’ Theorem to estimate the conditional probability of AIS 3+ skeletal injury given that an occupant is osteoporotic for the injury to the head, spine, thorax, lower extremities, and upper extremities. This requires the conditional probabilities of osteoporosis given AIS 3+ injury for each of the body regions, which were determined from analysis of the Crash Injury Research and Engineering Network database. It also requires information on probability of osteoporosis in the crash-involved population and the probabilities of AIS 3+ skeletal injury to different body regions in crashes. The latter probabilities were obtained from the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) database. The former was obtained by modeling the probability of osteoporosis in the US populations using data from the 2006 National Health Examination Nutrition Survey and applying this model to the estimate of the crash-involved population in NASS-CDS. To attempt to account for the effects of age on injury outcome that are independent of osteoporosis, only data from occupants who were 60 years of age or older were used in all analyses. Results indicate that the only body region that experiences a statistically significant change in fracture injury risk with osteoporosis is the spine, for which osteoporosis increases the risk of AIS 3+ fracture by 3.28 times, or from 0.41% to 1.34% ( p < 0.0001). This finding suggests that the increase in AIS 3+ injury risk with age for non-spine injuries is likely influenced by factors other than osteoporosis.

The Effect of Air Bags on Pregnancy Outcomes in Washington State

To estimate whether air-bag deployment is associated with an increased risk of adverse pregnancy outcomes. We performed a retrospective cohort study to assess the effect of air-bag availability and air-bag deployment on the risk of adverse pregnancy outcomes among pregnant, front-seat occupants in motor vehicle crashes in Washington State. Pregnant women involved in motor vehicle crashes were identified by linking birth and fetal death certificate data with Washington State Patrol crash data, which reported air-bag availability and deployment. We calculated relative risks (RRs) of adverse maternal and perinatal outcomes and 95% confidence intervals (CIs) using Poisson regression, adjusted for maternal age, seatbelt use, and vehicle model year. We found no increased risk of adverse maternal or perinatal pregnancy outcomes among occupants of air-bag-equipped vehicles in all collisions (n=2,207) compared with those in vehicles without air bags (n=1,141). Among crashes in which air-bag deployment would be likely, we found a nonsignificant 70% increased risk of preterm labor (RR 1.7, 95% CI 0.9-3.2) and a nonsignificant threefold increased risk (RR 3.1, 95% CI 0.4-22.1) of fetal death among occupants in vehicles with air-bag deployment compared with occupants in vehicles without air bags, although fetal death results were limited by small numbers (2/198 [1.0%] in pregnant women whose air bags deployed; 2/622 [0.3%] in pregnant women whose air bags did not deploy). Our findings provide clinicians with evidence to advise women that air bags do not seem to elevate risk of most potential adverse outcomes during pregnancy. II.

Appropriate analysis of CIREN data: Using NASS-CDS to reduce bias in estimation of injury risk factors in passenger vehicle crashes

The Crash Injury Research Engineering Network (CIREN) database contains detailed medical and crash information on a large number of severely injured occupants in motor vehicle crashes. CIREN's major limitation for stand-alone analyses to explore injury risk factors is that control subjects without a given injury type must have another severe injury to be included in the database. This leads to bias toward the null in the estimation of risk associations. One method to cope with this limitation is to obtain information about occupants without a given injury type from the National Automotive Sampling System's Crashworthiness Data System (NASS-CDS), which is a probability sample of towaway crashes, containing similar crash information, but less medical detail. Combining CIREN and NASS-CDS in this manner takes advantage of the increased sample size when outcomes are available in both datasets; otherwise NASS-CDS can serve as a sample of controls to be combined with CIREN cases, possibly under a sensitivity analysis that includes and excludes NASS-CDS subjects whose status as a control is uncertain. Because CIREN is not a probability sample of crashes that meet its inclusion criteria, we develop a method to estimate the probability of selection for the CIREN cases using data from NASS-CDS. These estimated probabilities are then used to compute “pseudo-weights” for the CIREN cases. These pseudo-weights not only allow for reduced bias in the estimation of risk associations, they allow direct prevalence estimates to be made using medical outcome data available only in CIREN. We illustrate the use of these methods with both simulation studies and application to estimation of prevalence and predictors of AIS 3+ injury risk to head, thorax, and lower extremity regions, as well as prevalence and predictors of acetabular pelvic fractures. Results of these analyses demonstrate combining NASS and CIREN data can yield improvements in mean square error and nominal confidence interval coverage over analyses that use either the NASS-CDS or the CIREN sample alone.

Prehospital predictors of risk for pelvic fractures in pediatric trauma patients

Pelvic fractures are uncommon in children, but can occur as a result of high-energy impact injuries to the lower torso in association with blunt trauma. Pelvic fractures can be associated with significant morbidity while the work-up and treatment for these injuries is costly. The aim was to identify risk factors that help determine which pediatric trauma patients are at highest risk of sustaining a pelvic fracture to aid in the development of criteria for the targeted use of pelvic radiographic imaging. A retrospective analysis was conducted using the only pediatric trauma registry in the state of Maryland, located at The Johns Hopkins Children's Center. All blunt trauma patients who were younger than 15 years of age from 1990 to 2005 were included in the analysis (n = 13,360) with a final diagnosis of pelvic fracture as the primary outcome of interest. Comparisons were made using Pearson's chi-square for categorical and the Mann-Whitney rank sum test for non-normally distributed variables. Pelvic fractures following blunt trauma in children are associated with age, race, place and mechanism of injury. Compared to children 4 years and younger, pelvic fractures were more likely to occur in children aged 5-9 years (OR = 3; P = 0.000), as well as 10-14 years (OR = 5; P = 0.000). Compared to blunt trauma injuries from falls, children who were struck by vehicles or who were occupants in motor vehicle crashes (MVC) were six times (P = 0.000) and twice (P = 0.02) as likely to sustain a pelvic fracture, respectively. Four factors were demonstrated by this study to be significantly associated with pediatric pelvic fractures: being Caucasian, age between 5 and 14 years, being struck as a pedestrian or a motor vehicle crash occupant. Identification of these factors may aid clinicians in selecting patients who are at highest risk for pelvic fracture and may benefit most from pelvic radiography.