Andrea N. Doud

Development of a Time Sensitivity Score for Frequently Occurring Motor Vehicle Crash Injuries

BACKGROUND Injury severity alone is a poor indicator of the time sensitivity of injuries. The purpose of the study was to quantify the urgency with which the most frequent motor vehicle crash injuries require treatment, according to expert physicians. STUDY DESIGN The time sensitivity was quantified for the top 95% most frequently occurring Abbreviated Injury Scale (AIS) 2+ injuries in the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) 2000-2011. A Time Sensitivity Score was developed using expert physician survey data in which physicians were asked to determine whether a particular injury should go to a Level I/II trauma center and the urgency with which that injury required treatment. RESULTS When stratifying by AIS severity, the mean Time Sensitivity Score increased with increasing AIS severity. The mean Time Sensitivity Scores by AIS severity were as follows: 0.50 (AIS 2); 0.78 (AIS 3); 0.92 (AIS 4); 0.97 (AIS 5); and 0.97 (AIS 6). When stratifying by anatomical region, the head, thorax, and abdomen were the most time sensitive. CONCLUSIONS Appropriate triage depends on multiple factors, including the severity of an injury, the urgency with which it requires treatment, and the propensity of a significant injury to be missed. The Time Sensitivity Score did not correlate highly with the widely used AIS severity scores, which highlights the inability of AIS scores to capture all aspects of injury severity. The Time Sensitivity Score can be useful in Advanced Automatic Crash Notification systems for identifying highly time sensitive injuries in motor vehicle crashes requiring prompt treatment at a trauma center.

Predicting patients that require care at a trauma center: Analysis of injuries and other factors

INTRODUCTION The detection of occult or unpredictable injuries in motor vehicle crashes (MVCs) is crucial in correctly triaging patients and thus reducing fatalities. The purpose of the study was to develop a metric that indicates the likelihood that an injury sustained in a MVC would require management at a Level I/II trauma centre (TC) versus a non-trauma centre (non-TC). METHODS Transfer Scores (TSs) were computed for 240 injuries that comprise the top 95% most frequently occurring injuries in the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) with an Abbreviated Injury Scale (AIS) severity of 2 or greater. A TS for each injury was computed using the proportions of patients involved in a MVC from the National Inpatient Sample (NIS) that were transferred to a TC or managed at a non-TC. Similarly, a TSMAIS that excludes patients with higher severity co-injuries was calculated using the proportion of patients with a maximum AIS (MAIS) equal to the AIS severity of a given injury. RESULTS The results indicated for injuries of a given AIS severity, body region, and injury type, there were large variations in the TSMAIS. Overall results demonstrated higher TSMAIS values when injuries were internal, haemorrhagic, intracranial or of moderate severity (AIS 3-5). Specifically, injuries to the head possessed a TSMAIS that ranged from 0.000 to 0.889, with head injuries of AIS 3-5 severities being the most likely to be transferred. DISCUSSION AND CONCLUSIONS The analysis indicated that the TSMAIS is not solely correlated with AIS severity and therefore it captures other important aspects of injury such as predictability and trauma system capabilities. The TS and TSMAIS can be useful in advanced automatic crash notification (AACN) research for the detection of highly unpredictable injuries in MVCs that require direct transport to a TC.

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 Fishers 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.

Functional outcomes of motor vehicle crash head injuries in pediatric and adult occupants

ABSTRACT Objective: The objective of the study was to develop a disability-based metric for motor vehicle crash (MVC) injuries, with a focus on head injuries, and compare the functional outcomes between the pediatric and adult populations. Methods: Disability risk (DR) was quantified using Functional Independence Measure (FIM) scores within the National Trauma Data Bank—Research Data System (NTDB-RDS) for the top 95% most frequently occurring Abbreviated Injury Scale (AIS) 3, 4, and 5 head injuries in NASS-CDS 2000–2011. Pediatric (ages 7–18), adult (19–45), middle-aged (46–65), and older adult (66+) patients with an FIM score available who were alive at discharge and had an AIS 3, 4, or 5 injury were included in the study. The NTDB-RDS contains a truncated form of the FIM instrument, including 3 items (self-feed, locomotion, and verbal expression), each graded on a scale of 1 (full functional dependence) to 4 (full functional independence). Patients within each age group were classified as disabled or not disabled based on the FIM scale. The DR was calculated for each age group by dividing the number of patients who sustained a specific injury and were disabled by the number of patients who sustained the specific injury. To account for the impact of more severe associated coinjuries, a maximum AIS (MAIS) adjusted DR (DRMAIS) was also calculated for each injury. DR and DRMAIS ranged from 0 (0% disability risk) to 1 (100% disability risk). Results: An analysis of the most frequent FIM components associated with disabling MVC head injuries revealed that disability across all 3 items (self-feed, locomotion, and expression) was the most frequent for pediatric and adult patients. Only locomotion was the most frequent for middle-aged and older adults. The mean DRMAIS for MVC head injuries was 35% for pediatric patients, 36% for adults, 38% for middle-aged adults, and 44% for older adults. Further analysis was conducted by grouping the head injuries into 8 groups based on the structure of injury and injury type. The pediatric population possessed higher DRMAIS values for brain stem injuries as well as loss of consciousness injuries. Older adults possessed higher DRMAIS values for contusion/hemorrhage injuries, epidural hemorrhage, intracerebral hemorrhage, skull fracture, and subdural/subarachnoid hemorrhage. Conclusion: At-risk populations such as pediatric and older adult patients possessed higher DRMAIS values for different head injuries. Disability in pediatric patients is critical due to loss of quality life years. Disability risk can supplement severity metrics to improve the ability of such metrics to discriminate the severity of different injuries that do not lead to death. Understanding of age-related differences in injury outcomes when compared to adults could inform future age-specific modifications to the AIS.

Evaluation of developmental metrics for utilization in a pediatric advanced automatic crash notification algorithm

ABSTRACT Objective: Appropriate treatment at designated trauma centers (TCs) improves outcomes among injured children after motor vehicle crashes (MVCs). Advanced Automatic Crash Notification (AACN) has shown promise in improving triage to appropriate TCs. Pediatric-specific AACN algorithms have not yet been created. To create such an algorithm, it will be necessary to include some metric of development (age, height, or weight) as a covariate in the injury risk algorithm. This study sought to determine which marker of development should serve as a covariate in such an algorithm and to quantify injury risk at different levels of this metric. Methods: A retrospective review of occupants age < 19 years within the MVC data set NASS-CDS 2000–2011 was performed. R2 values of logistic regression models using age, height, or weight to predict 18 key injury types were compared to determine which metric should be used as a covariate in a pediatric AACN algorithm. Clinical judgment, literature review, and chi-square analysis were used to create groupings of the chosen metric that would discriminate injury patterns. Adjusted odds of particular injury types at the different levels of this metric were calculated from logistic regression while controlling for gender, vehicle velocity change (delta V), belted status (optimal, suboptimal, or unrestrained), and crash mode (rollover, rear, frontal, near-side, or far-side). Results: NASS-CDS analysis produced 11,541 occupants age < 19 years with nonmissing data. Age, height, and weight were correlated with one another and with injury patterns. Age demonstrated the best predictive power in injury patterns and was categorized into bins of 0–4 years, 5–9 years, 10–14 years, and 15–18 years. Age was a significant predictor of all 18 injury types evaluated even when controlling for all other confounders and when controlling for age- and gender-specific body mass index (BMI) classifications. Adjusted odds of key injury types with respect to these age categorizations revealed that younger children were at increased odds of sustaining Abbreviated Injury Scale (AIS) 2+ and 3+ head injuries and AIS 3+ spinal injuries, whereas older children were at increased odds of sustaining thoracic fractures, AIS 3+ abdominal injuries, and AIS 2+ upper and lower extremity injuries. Conclusions: The injury patterns observed across developmental metrics in this study mirror those previously described among children with blunt trauma. This study identifies age as the metric best suited for use in a pediatric AACN algorithm and utilizes 12 years of data to provide quantifiable risks of particular injuries at different levels of this metric. This risk quantification will have important predictive purposes in a pediatric-specific AACN algorithm.

All-Terrain Vehicle Injury in Children and Youth: Examining Current Knowledge and Future Needs

BACKGROUND All-terrain vehicle (ATV)-related injuries remain a large public health problem in the United States and disproportionately affect American youth. Although children account for only 14-18% of ATV riders, they comprise 37-57% of those injured in ATV-related accidents. Since the U.S. Consumer Product Safety Commission began collecting data in 1982, 23% of ATV-related deaths have occurred in children. OBJECTIVE With this review, we outline the major risk factors for injuries among young ATV riders in the United States and suggest research-based interventions to successfully modify such risk factors. DISCUSSION We reviewed data from 16 published reviews regarding epidemiology and risk factors among ATV-related injuries in American children. All data pointed to young driver age and lack of appropriate safety equipment as major risk factors for such injuries. Although these risk factors are modifiable, legislation and programs designed to mitigate such risks have been unsuccessful. Among adults, the brief intervention model has become widely used among trauma patients exhibiting risky behaviors. Additionally, peer-to-peer interventions have demonstrated success with respect to drug and alcohol use in school-aged children. Both the brief and peer-to-peer interventions are promising avenues for decreasing risky ATV-related behavior in youths but have not been studied in this field. CONCLUSIONS ATV-related injuries disproportionately affect American youths. Although risk factors for such injuries are modifiable, current methods for intervention (mainly legislation) have not been successfully implemented. The brief intervention and peer-to-peer interventions have shown promise in other fields and should be studied with respect to pediatric ATV use.

Characterization of the occult nature of injury for frequently occurring motor vehicle crash injuries

BACKGROUND Occult injuries are not easily detected and can be potentially life-threatening. The purpose of this study was to quantify the perceived occultness of the most frequent motor vehicle crash injuries according to emergency medical services (EMS) professionals. STUDY DESIGN An electronic survey was distributed to 1,125 EMS professionals who were asked to quantify the likelihood that first responders would miss symptoms related to a particular injury on a 5-point Likert scale. The Occult Score for each injury was computed from the average of all the survey responses and normalized to be a continuous metric ranging from 0 to 1 where 0 is a non-occult (highly apparent on initial presentation) injury and 1 is an occult (unapparent on initial presentation) injury. RESULTS Overall, 110,671 survey responses were collected. The Occult Score ranged from 0 to 1 with a mean, median, and standard deviation of 0.443, 0.450, and 0.233, respectively. When comparing the Occult Score of an injury to its corresponding AIS severity, there was no relationship between the metrics. When stratifying by body region, injury type, and AIS severity, it was evident that AIS 2-4 abdominal injuries with lacerations, hemorrhage, or contusions were perceived as the most occult injuries. CONCLUSIONS Timely triage is key to reduce the morbidity and mortality associated with occult injuries. The Occult Score developed in this study to describe the predictability of an injury in a motor vehicle crash will be used as part of a larger effort, including incorporation into an advanced automatic crash notification (AACN) algorithm to detect crash conditions associated with a patients need for prompt treatment at a trauma center.

The spleen not taken: Differences in management and outcomes of blunt splenic injuries in teenagers cared for by adult and pediatric trauma teams in a single institution

BACKGROUND Nonoperative management (NOM) of blunt splenic injury, initially touted for the care of pediatric patients, has become the standard of care for stable trauma patients of all ages. In our institution, trauma patients younger than 16 years are managed by the pediatric surgery service and patients 16 years or older are managed by the adult trauma service. Angioembolization is routinely used for adults with blunt splenic injury but rarely used for pediatric patients. A retrospective chart review was performed to determine if more liberal use of angioembolization increases the success rate of NOM of blunt splenic injury in adolescents. METHODS Using our institutional trauma registry, we performed a retrospective chart review of 13- to 18-year-olds admitted with blunt splenic injury from 2007 to 2015. One hundred thirty-three patients were identified; 59 were 13- to 15-year-olds and cared for by the Pediatric Trauma service, whereas 74 were 16- to 18-year-olds and cared for by the Adult Trauma service. The cohorts were compared with respect to imaging performed, grade of injury, Injury Severity Score, presence of active extravasation or pseudoaneurysm, interventions performed, blood transfused, intensive care unit days, length of stay, complications, and 30-day mortality rates. RESULTS There were no significant differences in Injury Severity Score, incidence of active extravasation or pseudoaneurysm identified on computed tomography, or grade of injury between the two cohorts. More patients underwent angioembolization in the “adult” group (p = 0.001) with no difference in the success rate of NOM (p = 0.117). The overall failure rate of NOM of high-grade injuries was only 4.1%. CONCLUSION Failure of NOM in high-grade injuries is rare; as a result, the number needed to treat with prophylactic angioembolization would be around 37 patients, resulting in undue risk to many patients with no therapeutic benefit. No improvement in failure rate was seen with aggressive angioembolization, though a larger sample size is needed to rule out type 2 error. LEVEL OF EVIDENCE Therapeutic, level IV.

Predicting Pediatric Patients Who Require Care at a Trauma Center: Analysis of Injuries and Other Factors

BACKGROUND Triage decision correctness for children in motor vehicle crashes can be affected by occult injuries. There is a need to develop a transfer score (TS) metric for children that can help quantify the likelihood that an injury is present that would require transfer to a trauma center (TC) from a non-TC, and improve triage decision making. Ultimately, the TS metric might be useful in an advanced automatic crash notification algorithm, which uses vehicle telemetry data to predict the risk of serious injury after a motor vehicle crash using an approach that includes metrics to describe injury severity, time sensitivity, and predictability. STUDY DESIGN Transfer score metrics were calculated in 4 pediatric age groups (0 to 4, 5 to 9, 10 to 14, 15 to 18 years) for the most frequent motor vehicle crash injuries using the proportions of children transferred to a TC or managed at a non-TC using the National Inpatient Sample years 1998 to 2007. To account for the maximum Abbreviated Injury Scale (MAIS) injury, a co-injury adjusted transfer score (TSMAIS) was calculated. The TS and TSMAIS range from 0 to 1, with 1 indicating highly transferred injuries. RESULTS Injuries in younger patients were more likely to be transferred (median TS 0.48, 0.35, 0.25, and 0.23 for 0 to 4, 5 to 9, 10 to 14, and 15 to 18 years, respectively). Injuries more likely to be transferred in younger children occurred in the thorax and abdomen. Regardless of age, spine (median TSMAIS 0.59), head (median TSMAIS 0.48), and thorax (median TSMAIS 0.46) injuries had the highest frequency for transfer. CONCLUSIONS The TS metrics quantitatively describe age-specific transfer practices for children with particular injuries. This information can be useful in advanced automatic crash notification systems to alert first responders to the possibility of occult injuries and reduce undertriage of commonly missed injuries.

Characterization of the occult nature of frequently occurring pediatric motor vehicle crash injuries

BACKGROUND Occult injuries are those likely to be missed on initial assessment by first responders and, though initially asymptomatic, they may present suddenly and lead to rapid patient decompensation. No scoring systems to quantify the occultness of pediatric injuries have been established. Such a scoring system will be useful in the creation of an Advanced Automotive Crash Notification (AACN) system that assists first responders in making triage decisions following a motor vehicle crash (MVC). STUDY DESIGN The most frequent MVC injuries were determined for 0-4, 5-9, 10-14 and 15-18 year olds. For each age-specific injury, experts with pediatric trauma expertise were asked to rate the likelihood that the injury may be missed by first responders. An occult score (ranging from 0-1) was calculated by averaging and normalizing the responses of the experts polled. RESULTS Evaluation of all injuries across all age groups demonstrated greater occult scores for the younger age groups compared to older age groups (mean occult score 0-4yo: 0.61 ± 0.23, 5-9yo: 0.53 ± 0.25, 10-14yo: 0.48 ± 0.23, and 15-18yo: 0.42 ± 0.22, p < 0.01). Body-region specific occult scores revealed that experts judged abdominal, spine and thoracic injuries to be more occult than injuries to other body regions. CONCLUSIONS The occult scores suggested that injuries are more difficult to detect in younger age groups, likely given their inability to express symptoms. An AACN algorithm that can predict the presence of clinically undetectable injuries at the scene can improve triage of children with these injuries to higher levels of care.