Using a severity threshold to improve occupational injury surveillance: Assessment of a severe traumatic injury-based occupational health indicator across the International Classification of Diseases lexicon transition

BACKGROUND

Traumatic injury is a leading cause of death and disability among US workers. Severe injuries are less subject to systematic ascertainment bias related to factors such as reporting barriers, inpatient admission criteria, and workers' compensation coverage. A state-based occupational health indicator (OHI #22) was initiated in 2012 to track work-related severe traumatic injury hospitalizations. After 2015, OHI #22 was reformulated to account for the transition from the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) to ICD-10-CM. This study describes rates and trends in OHI #22, alongside corresponding metrics for all work-related hospitalizations.

METHODS

Seventeen states used hospital discharge data to calculate estimates for calendar years 2012-2019. State-panel fixed-effects regression was used to model linear trends in annual work-related hospitalization rates, OHI #22 rates, and the proportion of work-related hospitalizations resulting from severe injuries. Models included calendar year and pre- to post-ICD-10-CM transition.

RESULTS

Work-related hospitalization rates showed a decreasing monotonic trend, with no significant change associated with the ICD-10-CM transition. In contrast, OHI #22 rates showed a monotonic increasing trend from 2012 to 2014, then a significant 50% drop, returning to a near-monotonic increasing trend from 2016 to 2019. On average, OHI #22 accounted for 12.9% of work-related hospitalizations before the ICD-10-CM transition, versus 9.1% post-transition.

CONCLUSIONS

Although hospital discharge data suggest decreasing work-related hospitalizations over time, work-related severe traumatic injury hospitalizations are apparently increasing. OHI #22 contributes meaningfully to state occupational health surveillance efforts by reducing the impact of factors that differentially obscure minor injuries; however, OHI #22 trend estimates must account for the ICD-10-CM transition-associated structural break in 2015.

Elder child or young adult? Adolescent trauma mortality amongst pediatric and adult facilities

BACKGROUND

While it is assumed adolescents receive comparable trauma care at pediatric trauma centers (PTC), adult trauma centers (ATC), and combined facilities (MTC), this remains understudied.

METHODS

We conducted a retrospective cohort study through the NTDB evaluating patients 14-18 years of age who presented to an ACS-verified level 1 or 2 trauma facility between 1/1/2016 and 12/31/2019. Multiple logistic regression analyses were performed to compare mortality risk among trauma facility verification types.

RESULTS

91,881 adolescents presented after trauma over the four-years. Hypotension, severe TBI, firearm mechanism, and ISS >15 were associated with increased mortality. Compared to PTCs, the odds of trauma-related mortality were statistically higher at MTCs (OR 1.82, p = 0.004) and ATCs (OR 1.89-2.05, p = 0.001-0.002).

CONCLUSIONS

Injured adolescents receiving care at ATCs and MTCs have higher mortality risk than those cared for at PTCs. Further evaluation of factors associated with this observed difference is warranted and may help identify opportunities to improve outcomes in injured adolescents.

Increased Lengths of Stay, ICU, and Ventilator Days in Trauma Patients with Asymptomatic COVID-19 Infection

Background

The SARS-Cov-2 coronavirus has varying clinical effects—from asymptomatic patients to life-threatening illness and death. At the only Level 1 Trauma Center in a rural state, outcomes appeared worse in trauma patients who tested positive for COVID despite these patients presumably being asymptomatic or only mildly affected before their traumatic event. This study compares all trauma admissions that were COVID-positive to those who were not.

Methods

The institutional database was queried for all level 1 and 2 trauma activations from March 2020-July 2021. The analysis consisted of a multivariate regression between COVID-negative and the COVID-positive group controlling for age, injury severity score (ISS), and Glasgow Coma Score (GCS). Outcomes compared were hospital length-of-stay (LOS), ICU LOS, ventilator days, days to discharge to a facility, and in-hospital mortality.

Results

Hospital LOS was 2.7 days longer in the COVID-positive group (P < .0005). ICU LOS was 2.9 days longer for patients admitted to the ICU in the COVID positive-group (P = .017). Ventilator days were 4.7 days longer for patients requiring mechanical ventilation in the COVID-positive group (P = .002). Discharge to a post-acute facility required 6.1 more days in the COVID-positive group (P = .005).

Conclusion

Trauma patients presenting positive for COVID-19 are presumed to be asymptomatic before their traumatic event. Despite this, the physiologic toll of trauma combined with the COVID infection causes significantly worse clinical outcomes, including increasing hospital days in this patient population, which continues to tax the already burdened healthcare system.

Development and Validation of a Controlled Vocabulary: An OWL Representation of Organizational Structures of Trauma Centers and Trauma Systems

In trauma care and trauma care research there exists an implementation gap regarding a consistent controlled vocabulary to describe organizational aspects of trauma centers and trauma systems. This paper describes the development and evaluation of a controlled vocabulary for trauma care organizations. We give a detailed description of the involvement of domain experts in the domain analysis workflow and the authoring of definitions and additional term descriptions. Finally, the paper details the evaluation methodology to assess the initial version of the controlled vocabulary. The results of the evaluation show that our development process yields terms most of which find approval from domain experts not involved in the development. In addition, our evaluation tools resulted in valuable domain expert input to optimize the controlled vocabulary.

Long-term sustainability of Washington State's quality improvement initiative for the management of pediatric spleen injuries

BACKGROUND

Initial results of Washington State's quality improvement initiative addressing the management of blunt traumatic pediatric spleen injuries were published in 2008. In this update, we evaluated whether these effects were sustained over time.

METHODS

Data from the Washington Trauma Registry for years 1999-2001 (pre-intervention), 2003-2005 (post-intervention), and 2012-2014 (follow-up) were used in a retrospective cohort study. Children between ages 0 to 14 years who were hospitalized with a traumatic blunt spleen injury were included. Multivariable logistic regression was used to account for patient, injury, and hospital characteristics.

RESULTS

Overall, splenectomies continued to be less common with 8.3% of pediatric patients receiving splenectomies in the follow-up period compared with 14.3% and 7.2% in the preintervention and post-intervention periods (p = 0.034). After adjustment, splenectomies remained less likely to be performed in both post-intervention (OR = 0.37; 95% CI = 0.16-0.90) and follow-up periods (OR = 0.29; 95% CI = 0.12-0.70) compared to pre-intervention. Children were much more likely to be cared for at pediatric trauma hospitals in the follow-up period (OR = 5.13; 95% CI = 2.79-9.43) after adjustment.

CONCLUSIONS

Evaluation of this statewide quality improvement initiative showed that positive changes in management practices persist. This evidence suggests that statewide quality improvement initiatives can be sustainable with minimal ongoing effort.

LEVEL OF EVIDENCE

Level III.

State Trauma Registries as a Resource for Occupational Injury Surveillance and Research: Lessons From Washington State, 1998-2009

OBJECTIVES

Work-related traumatic injury is a leading cause of death and disability among US workers. Occupational injury surveillance is necessary for effective prevention planning and assessing progress toward Healthy People 2020 objectives. Our objectives were to (1) describe the Washington State Trauma Registry (WTR) as a resource for occupational injury surveillance and research, (2) compare the WTR with 2 population-based data sources more widely used for these purposes, and (3) compare the number of injuries ascertained by the WTR with other data sources.

METHODS

We linked WTR records to hospital discharge records in the Comprehensive Hospital Abstract Reporting System for 2009 and to workers' compensation claims from the Washington State Department of Labor and Industries for 1998 to 2008. We assessed the 3 data sources for overlap, concordance, and case ascertainment.

RESULTS

Of 9185 work-related injuries in the WTR, 3380 (37%) did not link to workers' compensation claims. Use of payer information in hospital discharge records along with the WTR work-relatedness field identified 20% more linked injuries as work related (n = 720) than did use of payer information alone (n = 602). The WTR identified substantial numbers of work-related injuries that were not identified through workers' compensation or hospital discharge records.

CONCLUSIONS

Workers' compensation and hospital discharge databases are important but incomplete data sources for work-related injuries; many work-related injuries are not billed to, reported to, or covered by workers' compensation. Trauma registries are well positioned to capture severe work-related injuries and should be included in comprehensive injury surveillance efforts.

OOSTT: a Resource for Analyzing the Organizational Structures of Trauma Centers and Trauma Systems

Organizational structures of healthcare organizations has increasingly become a focus of medical research. In the CAFÉ project we aim to provide a web-service enabling ontology-driven comparison of the organizational characteristics of trauma centers and trauma systems. Trauma remains one of the biggest challenges to healthcare systems worldwide. Research has demonstrated that coordinated efforts like trauma systems and trauma centers are key components of addressing this challenge. Evaluation and comparison of these organizations is essential. However, this research challenge is frequently compounded by the lack of a shared terminology and the lack of effective information technology solutions for assessing and comparing these organizations. In this paper we present the Ontology of Organizational Structures of Trauma systems and Trauma centers (OOSTT) that provides the ontological foundation to CAFÉ's web-based questionnaire infrastructure. We present the usage of the ontology in relation to the questionnaire and provide the methods that were used to create the ontology.

Effects of registered nurse staffing level on hospital-acquired conditions in cardiac surgery patients: A propensity score matching analysis

BACKGROUND

The ramifications of inadequate nurse staffing may have serious consequences due to reimbursement policies.

PURPOSE

To determine the effects of registered nurse staffing on hospital-acquired conditions in cardiac surgery patients.

METHOD

Data from the 2009 to 2011 Nationwide Inpatient Sample were used to construct a propensity score-matched cohort. Multivariate regressions were performed to compare the probability, length of stay, mortality, and costs of three common hospital-acquired conditions between low- and high-staffing hospitals.

RESULTS

A total of 439,365 patients in low-staffing hospitals were 1:1 matched to patients in high-staffing hospitals. High-staffing hospitals had 10% to 25% fewer cases (adjusted odds ratio [AOR] 0.75-0.90, p < .0001), 5% to 20% lower mortality (AOR 0.80-0.95, p < .0001), and 4% to 6% shorter length of stay (coefficient -0.06 to -0.04, p < .0001). The costs for patients with hospital-acquired conditions were 13% to 17% greater in high-staffing hospitals (coefficient 0.13-0.17, p < .0001).

CONCLUSIONS

Alternatives to the current staffing and reimbursement policies should be considered to reduce hospital-acquired conditions.

Industrial Injury Hospitalizations Billed to Payers Other Than Workers' Compensation: Characteristics and Trends by State

OBJECTIVE

To describe characteristics of industrial injury hospitalizations, and to test the hypothesis that industrial injuries were increasingly billed to non-workers' compensation (WC) payers over time.

DATA SOURCES

Hospitalization data for 1998-2009 from State Inpatient Databases, Healthcare Cost and Utilization Project, and Agency for Healthcare Research and Quality.

STUDY DESIGN

Retrospective secondary analyses described the distribution of payer, age, gender, race/ethnicity, and injury severity for injuries identified using industrial place of occurrence codes. Logistic regression models estimated trends in expected payer.

PRINCIPAL FINDINGS

There was a significant increase over time in the odds of an industrial injury not being billed to WC in California and Colorado, but a significant decrease in New York. These states had markedly different WC policy histories. Industrial injuries among older workers were more often billed to a non-WC payer, primarily Medicare.

CONCLUSIONS

Findings suggest potentially dramatic cost shifting from WC to Medicare. This study adds to limited, but mounting evidence that, in at least some states, the burden on non-WC payers to cover health care for industrial injuries is growing, even while WC-related employer costs are decreasing-an area that warrants further research.

A New Method to Classify Injury Severity by Diagnosis: Validation Using Workers' Compensation and Trauma Registry Data

PURPOSE

Acute work-related trauma is a leading cause of death and disability among U.S. workers. Existing methods to estimate injury severity have important limitations. This study assessed a severe injury indicator constructed from a list of severe traumatic injury diagnosis codes previously developed for surveillance purposes. Study objectives were to: (1) describe the degree to which the severe injury indicator predicts work disability and medical cost outcomes; (2) assess whether this indicator adequately substitutes for estimating Abbreviated Injury Scale (AIS)-based injury severity from workers' compensation (WC) billing data; and (3) assess concordance between indicators constructed from Washington State Trauma Registry (WTR) and WC data.

METHODS

WC claims for workers injured in Washington State from 1998 to 2008 were linked to WTR records. Competing risks survival analysis was used to model work disability outcomes. Adjusted total medical costs were modeled using linear regression. Information content of the severe injury indicator and AIS-based injury severity measures were compared using Akaike Information Criterion and R(2).

RESULTS

Of 208,522 eligible WC claims, 5 % were classified as severe. Among WC claims linked to the WTR, there was substantial agreement between WC-based and WTR-based indicators (kappa = 0.75). Information content of the severe injury indicator was similar to some AIS-based measures. The severe injury indicator was a significant predictor of WTR inclusion, early hospitalization, compensated time loss, total permanent disability, and total medical costs.

CONCLUSIONS

Severe traumatic injuries can be directly identified when diagnosis codes are available. This method provides a simple and transparent alternative to AIS-based injury severity estimation.

Disparities in occupational injury hospitalization rates in five states (2003-2009)

BACKGROUND

Achievement of health equity and elimination of disparities are overarching goals of Healthy People 2020, yet there is a paucity of population-based data regarding race/ethnicity-based disparities in occupational injuries.

METHODS

Hospital discharge data for five states (Arizona, California, Florida, New Jersey, and New York) were obtained from the Healthcare Cost & Utilization Project (HCUP) for 2003-2009. Age-adjusted rates and trends for work-related injury hospitalizations were calculated using negative binomial regression (reference category: non-Latino white).

RESULTS

Latinos were significantly more likely to have a work-related traumatic injury hospitalization. The disparity for Latinos was greatest for machinery-related hospitalizations. Latinos were also more likely to have a fall-related hospitalization. African-Americans were more likely to have an occupational assault-related hospitalization, but less likely to have a fall-related hospitalization.

CONCLUSIONS

We found evidence of substantial multistate disparities in occupational injury-related hospitalizations. Enhanced surveillance and further research are needed to identify and address underlying causes.

Nonconvulsive seizures and status epilepticus in pediatric head trauma: A national survey

Objectives:

It remains uncertain whether nonconvulsive seizures and nonconvulsive status epilepticus in pediatric traumatic brain injury are deleterious to the brain and/or impact the recovery from injury. Consequently, optimal electroencephalographic surveillance and management is unknown. We aimed to determine specialists’ opinion regarding the detection and treatment of nonconvulsive seizures or nonconvulsive status epilepticus in pediatric traumatic brain injury, regardless of their practice.

Methods:

In 2012, 183 surveys were sent to all 93 neurologists, 27 neurosurgeons, and 63 intensivists in the14 tertiary pediatric hospitals across Canada. The survey included an initial scenario of pediatric TBI that evolved into three further scenarios. Each scenario had required responses and an embedded branching logic algorithm ascertaining clinical management. The survey instrument assimilated data about the importance of nonconvulsive status epilepticus and nonconvulsive seizures detection and treatment, and whether they are a cause of brain injury that adversely affects neurologic outcomes.

Results:

Of the 79 specialists who replied (43% response rate), 68%–78% elected to order an electroencephalographic across all four scenarios, and one-third (31%–36%; scenario dependent) would request an urgent electroencephalographic (within the hour) in the comatose pediatric traumatic brain injury patient. In the absence of pharmacologic paralysis or intracranial pressure spikes, half-hour electroencephalographic (41%–55%) was preferred over ⩾24-h continuous electroencephalographic monitoring (29%–40%). Finally, nonconvulsive status epilepticus (81%–87%) and nonconvulsive seizures (61%–73%) were considered to be a cause of poor neurologic outcomes warranting aggressive pharmacologic management.

Conclusion:

The Canadian specialists’ opinion is that nonconvulsive seizures and nonconvulsive status epilepticus are biomarkers of brain injury and contribute to worsened outcomes. This suggests the urgency of future outcome-oriented research in the identification and management of nonconvulsive seizures or nonconvulsive status epilepticus.

Do prehospital criteria optimally assign injured children to the appropriate level of trauma team activation and emergency department disposition at a level I pediatric trauma center?

PURPOSE

To examine the association of prehospital criteria with the appropriate level of trauma team activation (TTA) and emergency department (ED) disposition among injured children at a level I pediatric trauma center.

METHODS

Injured children younger than 15 years and transported by emergency medical services (EMS) from the scene of injury between January 1, 2008 and December 31, 2011 were identified using the institution's trauma registry. Logistic regression was used to study the main outcomes of interest, full TTA (FTTA) and ED disposition.

RESULTS

Out of 3,213 children, 1,991 were eligible and analyzed. Only 279 children initiated the FTTA and 73.9% were admitted. Having a chest injury, abnormal heart rate or Glasgow Coma Scale less than 9 (GCSLT9) in the field was associated with higher odds of initiating the FTTA (odds ratio [OR] = 3.33, 95% confidence interval [CI] 1.54-7.20; OR = 2.59, CI 1.15-5.79 and OR = 2.67, CI 1.14-6.22, respectively). Children with the criteria above in addition to abdominal injury were more likely to be discharged to the ICU, OR or morgue compared to those without them.

CONCLUSION

Children with GCSLT9, abnormal heart rate, chest and abdominal injury showed a strong association with FTTA and higher resource utilization.

Using injury severity to improve occupational injury trend estimates

BACKGROUND

Hospitalization-based estimates of trends in injury incidence are also affected by trends in health care practices and payer coverage that may differentially impact minor injuries. This study assessed whether implementing a severity threshold would improve occupational injury surveillance.

METHODS

Hospital discharge data from four states and a national survey were used to identify traumatic injuries (1998-2009). Negative binomial regression was used to model injury trends with/without severity restriction, and to test trend divergence by severity.

RESULTS

Trend estimates were generally biased downward in the absence of severity restriction, more so for occupational than non-occupational injuries. Restriction to severe injuries provided a markedly different overall picture of trends.

CONCLUSIONS

Severity restriction may improve occupational injury trend estimates by reducing temporal biases such as increasingly restrictive hospital admission practices, constricting workers' compensation coverage, and decreasing identification/reporting of minor work-related injuries. Injury severity measures should be developed for occupational injury surveillance systems.

Predicting work-related disability and medical cost outcomes: a comparison of injury severity scoring methods

INTRODUCTION

Acute work-related trauma is a leading cause of death and disability among U.S. workers. Occupational health services researchers have described the pressing need to identify valid injury severity measures for purposes such as case-mix adjustment and the construction of appropriate comparison groups in programme evaluation, intervention, quality improvement, and outcome studies. The objective of this study was to compare the performance of several injury severity scores and scoring methods in the context of predicting work-related disability and medical cost outcomes.

METHODS

Washington State Trauma Registry (WTR) records for injuries treated from 1998 to 2008 were linked with workers' compensation claims. Several Abbreviated Injury Scale (AIS)-based injury severity measures (ISS, New ISS, maximum AIS) were estimated directly from ICD-9-CM codes using two software packages: (1) ICDMAP-90, and (2) Stata's user-written ICDPIC programme (ICDPIC). ICDMAP-90 and ICDPIC scores were compared with existing WTR scores using the Akaike Information Criterion, amount of variance explained, and estimated effects on outcomes. Competing risks survival analysis was used to evaluate work disability outcomes. Adjusted total medical costs were modelled using linear regression.

RESULTS

The linked sample contained 6052 work-related injury events. There was substantial agreement between WTR scores and those estimated by ICDMAP-90 (kappa=0.73), and between WTR scores and those estimated by ICDPIC (kappa=0.68). Work disability and medical costs increased monotonically with injury severity, and injury severity was a significant predictor of work disability and medical cost outcomes in all models. WTR and ICDMAP-90 scores performed better with regard to predicting outcomes than did ICDPIC scores, but effect estimates were similar. Of the three severity measures, maxAIS was usually weakest, except when predicting total permanent disability.

CONCLUSIONS

Injury severity was significantly associated with work disability and medical cost outcomes for work-related injuries. Injury severity can be estimated using either ICDMAP-90 or ICDPIC when ICD-9-CM codes are available. We observed little practical difference between severity measures or scoring methods. This study demonstrated that using existing software to estimate injury severity may be useful to enhance occupational injury surveillance and research.

Who pays for work-related traumatic injuries? Payer distribution in washington state by ethnicity, injury severity, and year (1998-2008)

BACKGROUND

Acute work-related trauma is a leading cause of death and disability for U.S. workers but it is difficult to obtain information about injured workers not covered by workers' compensation (WC). This study aimed to: (1) describe trends in expected payer and linkage to WC claims, (2) compare characteristics of injured workers who did and did not have a linked WC claim, and (3) describe variation in expected payer and linkage to WC claims by ethnicity and injury severity.

METHODS

Data for injuries occurring from 1998 through 2008 were obtained from the Washington State Trauma Registry and linked to WC claims.

RESULTS

We found that 27% of work-related traumatic injuries did not have WC listed as a payer, while 37% did not link to a WC claim. Among those with WC listed as a payer, the odds of having a linked WC claim were 57% lower for workers with other non-WC insurance compared with the otherwise uninsured. Latinos were more likely to have a linked WC claim compared with non-Latinos, but there was no significant difference after partially controlling for WC-covered employment and other insurance.

CONCLUSIONS

This study demonstrated the importance of considering differential access to other insurance coverage and adaptation by health care settings to financial pressures when assessing trends in occupational injury incidence and reporting, especially when using WC as a proxy for work-relatedness. The addition of occupation, industry, and work status to trauma registries and hospital discharge databases would improve surveillance, research, policy and prevention efforts.

Predicting work-related disability and medical cost outcomes: estimating injury severity scores from workers' compensation data

PURPOSE

Acute work-related trauma is a leading cause of death and disability among US workers. The research objectives were to assess: (1) the feasibility of estimating Abbreviated Injury Scale-based injury severity scores (ISS) from ICD-9-CM codes available in workers' compensation (WC) medical billing data, (2) whether ISS predicts work-related disability and medical cost outcomes, (3) whether ISS adds value over other injury severity proxies, and (4) whether the utility of ISS differs for an all-injury sample compared with three specific injury samples (amputations, extremity fractures, traumatic brain injury).

METHODS

ISS was estimated from ICD-9-CM codes using Stata's user-written -icdpic- program for 208,522 compensable nonfatal WC claims for workers injured in Washington State from 1998 to 2008. The Akaike Information Criterion and R(2) were used to compare severity measures. Competing risks survival analysis was used to evaluate work disability outcomes. Adjusted total medical costs were modeled using linear regression.

RESULTS

Work disability and medical costs increased monotonically with injury severity. For a subset of 4,301 claims linked to the Washington State Trauma Registry (WTR), there was moderate agreement between WC-based ISS and WTR-based ISS. Including ISS together with an early hospitalization indicator resulted in the most informative models; however, early hospitalization is a more downstream measure.

CONCLUSIONS

ISS was significantly associated with work disability and medical cost outcomes for work-related injuries. Injury severity should be considered as a potential confounder for occupational injury intervention, program evaluation, or outcome studies, and can be estimated using existing software when ICD-9-CM codes are available.

Association between helicopter vs ground emergency medical services and survival for adults with major trauma

CONTEXT

Helicopter emergency medical services and their possible effect on outcomes for traumatically injured patients remain a subject of debate. Because helicopter services are a limited and expensive resource, a methodologically rigorous investigation of its effectiveness compared with ground emergency medical services is warranted.

OBJECTIVE

To assess the association between the use of helicopter vs ground services and survival among adults with serious traumatic injuries.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study involving 223,475 patients older than 15 years, having an injury severity score higher than 15, and sustaining blunt or penetrating trauma that required transport to US level I or II trauma centers and whose data were recorded in the 2007-2009 versions of the American College of Surgeons National Trauma Data Bank.

INTERVENTIONS

Transport by helicopter or ground emergency services to level I or level II trauma centers.

MAIN OUTCOME MEASURES

Survival to hospital discharge and discharge disposition.

RESULTS

A total of 61,909 patients were transported by helicopter and 161,566 patients were transported by ground. Overall, 7813 patients (12.6%) transported by helicopter died compared with 17,775 patients (11%) transported by ground services. Before propensity score matching, patients transported by helicopter to level I and level II trauma centers had higher Injury Severity Scores. In the propensity score-matched multivariable regression model, for patients transported to level I trauma centers, helicopter transport was associated with an improved odds of survival compared with ground transport (odds ratio [OR], 1.16; 95% CI, 1.14-1.17; P < .001; absolute risk reduction [ARR], 1.5%). For patients transported to level II trauma centers, helicopter transport was associated with an improved odds of survival (OR, 1.15; 95% CI, 1.13-1.17; P < .001; ARR, 1.4%). A greater proportion (18.2%) of those transported to level I trauma centers by helicopter were discharged to rehabilitation compared with 12.7% transported by ground services (P < .001), and 9.3% transported by helicopter were discharged to intermediate facilities compared with 6.5% by ground services (P < .001). Fewer patients transported by helicopter left level II trauma centers against medical advice (0.5% vs 1.0%, P < .001).

CONCLUSION

Among patients with major trauma admitted to level I or level II trauma centers, transport by helicopter compared with ground services was associated with improved survival to hospital discharge after controlling for multiple known confounders.

Trends in US pediatric drowning hospitalizations, 1993-2008

BACKGROUND

In the United States, drowning is the second leading cause of unintentional injury death in children aged 1 to 19 years, accounting for nearly 1100 deaths per year. Although a decline in overall fatal drowning deaths among children has been noted, national trends and disparities in pediatric drowning hospitalizations have not been reported.

METHODS

To describe trends in pediatric drowning in the United States and provide national benchmarks for state and regional comparisons, we analyzed existing data (1993-2008) from the Nationwide Inpatient Sample, the largest, longitudinal, all-payer inpatient care database in the United States. Children aged 0 to 19 years were included. Annual rates of drowning-related hospitalizations were determined, stratified by age, gender, and outcome.

RESULTS

From 1993 to 2008, the estimated annual incidence rate of pediatric hospitalizations associated with drowning declined 49% from 4.7 to 2.4 per 100 000 (P < .001). The rates declined for all age groups and for both males and females. The hospitalization rate for males remained consistently greater than for females at each point in time. Rates of fatal drowning hospitalization declined from 0.5 (95% confidence interval, 0.4-0.7) deaths per 100 000 in 1993-1994 to 0.3 (95% confidence interval, 0.2-0.4) in 2007-2008 (P < .01). No difference was observed in the mean hospital length of stay over time.

CONCLUSIONS

Pediatric hospitalization rates for drowning have decreased over the past 16 years. Our study provides national estimates of pediatric drowning hospitalization that can be used as benchmarks to target and assess prevention strategies.

Gender and Age Differences among Teen Drivers in Fatal Crashes

To identify age and gender differences among teen drivers in fatal crashes, we analyzed FARS data for 14,026crashes during 2007-2009. Compared with female teenagers, crashes of male teenagers were significantly more likely to involve BACs of 0.08% or more (21% vs. 12%), speeding (38% vs. 25%), reckless driving (17% vs. 14%), night driving (41% vs. 36%) and felony crashes (hit-and-run, homicide, or manslaughter) (8% vs. 6%) (all χ(2) p<0.001). Conversely, crashes of female teenagers were more likely to involve right angle ("t-bone") crashes (23% vs. 17%). Some crash characteristics associated with males and known to play a major role in crash causation also are more common in the youngest teenagers; for example, crashes of drivers age 15 or 16 were more likely than crashes of older teens to involve speeding or reckless driving. Crashes of drivers with BACs of 0.08% or higher increased with age in both genders. Some age effects differed by gender: for example, the proportion of crashes of female teens that involved speeding dropped from 38% to 22% between ages 15 and 19, while for males about 38% of crashes at each age involved speeding. The gender and age differences observed in teen drivers suggest opportunities for targeted driver training - for example, simulator training modules specifically tailored for male or female teenagers. Technology-based tools could also be developed to help parents to focus on the reckless driving tendencies of their sons. Insurance companies should consider ways to incentivize young males to drive more responsibly.

Assessing external cause of injury coding accuracy for transport injury hospitalizations

External cause of injury codes (E codes) capture circumstances surrounding injuries. While hospital discharge data are primarily collected for administrative/billing purposes, these data are secondarily used for injury surveillance. We assessed the accuracy and completeness of hospital discharge data for transport-related crashes using trauma registry data as the gold standard. We identified mechanisms of injury with significant disagreement and developed recommendations to improve the accuracy of E codes in administrative data. Overall, we linked 2,192 (99.9 percent) of the 2,195 discharge records to trauma registry records. General mechanism categories showed good agreement, with 84.7 percent of records coded consistently between registry and discharge data (Kappa 0.762, p < .001). However, agreement was lower for specific categories (e.g., ATV crashes), with discharge records capturing only 70.4 percent of cases identified in trauma registry records. Efforts should focus on systematically improving E-code accuracy and detail through training, education, and informatics such as automated data linkages to trauma registries.

Variability in pediatric splenic injury care: results of a national survey of general surgeons

BACKGROUND

Although nonoperative management is the standard of care for hemodynamically stable children with blunt splenic trauma, significant variation in practice exists. Little attention has been given to physician factors associated with management differences.

DESIGN

Nationally representative mail survey conducted in June 2008.

SETTING

United States.

PARTICIPANTS

Ten percent random sample of active, dues-paying fellows in the American College of Surgeons.

MAIN OUTCOME MEASURES

Knowledge, attitudes, and beliefs toward pediatric splenic injury management, including the role of clinical practice guidelines.

RESULTS

Almost all of the 375 responding surgeons (97.4%) agreed that surgical intervention is not immediately necessary for hemodynamically stable children. However, surgeons reported significant disagreement regarding whether blood should be administered before operative intervention for hemodynamically unstable children and whether explorative surgery is needed for stable patients with evidence of contrast extravasation on computed tomography. Only 18.7% of surgeons reported being very familiar with the clinical practice guidelines for the management of pediatric blunt splenic trauma from either the Eastern Association for the Surgery of Trauma or the American Pediatric Surgical Association. Surgeons who were very familiar with either guideline were significantly more likely to rate the guidelines as beneficial (90.0% vs 72.8%, P = .002).

CONCLUSIONS

General surgeons reported varying degrees of familiarity with and use of clinical practice guidelines for pediatric splenic injury management. Limited pediatric experience and lack of pediatric hospital resources may limit more widespread adoption of nonoperative management. Targeted educational interventions may help increase surgeon knowledge of guidelines and best practices.

Perioperative use of cuffed endotracheal tubes is advantageous in young pediatric burn patients

Uncuffed endotracheal tubes traditionally have been preferred over cuffed endotracheal tubes in young pediatric patients. However, recent evidence in elective pediatric surgical populations suggests otherwise. Because young pediatric burn patients can pose unique airway and ventilation challenges, we reviewed adverse events associated with the perioperative use of cuffed and uncuffed endotracheal tubes. We retrospectively reviewed 327 cases of operating room endotracheal intubation for general anesthesia in burned children 0-10 years of age over a 10-year period. Clinical airway outcomes were compared using multivariable logistic regression, controlling for relevant patient and injury characteristics. Compared to those receiving cuffed tubes, children receiving uncuffed tubes were significantly more likely to demonstrate clinically significant loss of tidal volume (odds ratio 10.62, 95% confidence interval 2.2-50.5) and require immediate reintubation to change tube size/type (odds ratio 5.54, 95% confidence interval 2.1-13.6). No significant differences were noted for rates of post-extubation stridor. Our data suggest that operating room use of uncuffed endotracheal tubes in such patients is associated with increased rates of tidal volume loss and reintubation. Due to the frequent challenge of airway management in this population, strategies should emphasize cuffed endotracheal tube use that is associated with lower rates of airway manipulation.

Impact of helmets on injuries to riders of all-terrain vehicles

BACKGROUND

Although helmet use has been shown to be effective in reducing traumatic brain injuries (TBIs) due to motorcycle and bicycle crashes, it is unknown whether helmet use is associated with different injury patterns and severity for users of all-terrain vehicles (ATVs).

OBJECTIVES

To compare likelihood of injury and death between helmeted and unhelmeted riders of ATVs.

METHODS

The National Trauma Data Bank for years 2002-2006 was used to examine the records of 11 589 patients hospitalized for injuries resulting from ATV use. The likelihood of receiving a TBI diagnosis or a significant injury to other body regions and differences in injury severity and in-hospital mortality between helmeted and unhelmeted ATV riders were compared.

RESULTS

After multivariable adjustment, compared with helmeted riders, unhelmeted riders were significantly more likely to sustain any TBI (OR 1.62, 95% CI 1.49 to 1.76, p<0.001) and major/severe TBI (OR 3.19, 95% CI 2.39 to 4.25, p<0.001). Unhelmeted riders were significantly more likely to die while in hospital than were helmeted riders (OR 2.58, 95% CI 1.79 to 3.71, p<0.001). Significant injuries to the neck and face regions were also significantly more likely in unhelmeted riders (OR 3.53, 95% CI 1.28 to 9.71, p = 0.015, and OR 1.94, 95% CI 1.32 to 2.84, p = 0.001, respectively).

CONCLUSIONS

ATV riders who do not wear helmets are more likely to receive significant injuries to the head, face, and neck. Prevention strategies and enforceable policy interventions to increase helmet use among ATV riders appear warranted.

Trends in hospitalizations associated with pediatric traumatic brain injuries

OBJECTIVES

The goals were to describe trends in pediatric traumatic brain injury hospitalizations in the United States and to provide national benchmarks for state and regional comparisons.

METHODS

Analysis of existing data (1991-2005) from the Nationwide Inpatient Sample, the largest longitudinal, all-payer, inpatient care database in the United States, was performed. Children 0 to 19 years of age were included. Annual rates of traumatic brain injury-related hospitalizations, stratified according to age, gender, severity of traumatic brain injury, and outcome, were determined.

RESULTS

From 1991 to 2005, the estimated annual incidence rate of pediatric hospitalizations associated with traumatic brain injury decreased 39%, from 119.4 to 72.7 hospitalizations per 100,000. The rates decreased for all age groups and for both boys and girls, although the rate for boys remained consistently higher at each time point. Fatal hospitalization rates decreased from 3.5 deaths per 100,000 in 1991-1993 to 2.8 deaths per 100,000 in 2003-2005. The rate of mild traumatic brain injury hospitalizations accounted for most of the overall decrease, whereas nonfatal hospitalization rates for moderate and severe traumatic brain injuries remained relatively unchanged.

CONCLUSIONS

Although pediatric hospitalization rates for mild traumatic brain injuries have decreased over the past 15 years, rates for moderate and severe traumatic brain injuries are relatively unchanged. Our study provides national estimates of pediatric traumatic brain injury hospitalizations that can be used as benchmarks to increase injury prevention effectiveness through targeting of effective strategies.

Rural trauma: is trauma designation associated with better hospital outcomes?

CONTEXT

While trauma designation has been associated with lower risk of death in large urban settings, relatively little attention has been given to this issue in small rural hospitals.

PURPOSE

To examine factors related to in-hospital mortality and delayed transfer in small rural hospitals with and without trauma designation.

METHODS

Analysis of data from the Nationwide Inpatient Sample for discharges between 1998 and 2003 of patients hospitalized with moderate to major traumatic injury in nonfederal, short-stay rural hospitals with annual discharges of 1,500 or fewer patients (N = 9,590). Logistic regression was used to control for patient and hospital characteristics, stratifying by hospital volume. Main outcome measures were in-hospital death and transfer to another acute care facility after initial admission.

FINDINGS

A total of 333 patients (3.5%) died in-hospital. After adjusting for patient, injury and hospital characteristics, in-hospital death was more likely among patients treated at the non-designated hospitals with fewer than 500 discharges per year (OR 2.35; 95% CI 1.25-4.41) than among patients treated at similar trauma-designated hospitals. Patients admitted to non-designated hospitals were more likely to be transferred after admission, although this finding was significant only in the larger-volume hospitals with discharges of 500-1,500 per year (OR 1.41, 95% CI 1.08-1.83).

CONCLUSIONS

Associations between trauma designation and outcomes in rural hospitals warrant further study to determine whether expanding designation to more rural hospitals might lead to further improvement in trauma outcomes.

Safety restraint use linked to hospital use and charges in Arkansas

Crash data from 2001-2005 was linked to hospital discharge data to determine the impact of safety restraint use on crashed-related hospital charges and use for 4013 hospitalizations. Safety restraint use, year of hospitalization and age group affected the hospital charges and length of stay after a crash. Mean hospital charges were 44% greater for unrestrained patients ($44,736 versus $30,990); mean length of stay was 23% longer for the unrestrained (9.2 days versus 7.5 days). Lack of safety restraint use was associated with greater use of hospital resources. Prevention efforts should focus on increasing compliance.

Racial Disparities in Outcomes of Persons With Moderate to Severe Traumatic Brain Injury

BACKGROUND

Although racial differences in hospital outcomes are well known for medical conditions (eg, cardiovascular disease), it is unknown whether differences exist for patients with traumatic brain injury (TBI).

RESEARCH DESIGN

Using the National Trauma Data Bank, we examined racial and ethnic differences in hospital outcomes of 56,482 patients with moderate to severe TBI who were hospitalized in level I or II trauma-designated hospitals between 2000 and 2003. We examined racial and ethnic disparities in in-hospital mortality and the likelihood of survivors receiving postacute care at a rehabilitation center.

RESULTS

After multivariable adjustment, compared with whites, we observed increased in-hospital mortality for blacks (odds ratio [OR] = 1.19, P = 0.026) and Asians (OR = 1.41, P = 0.005). We observed a trend toward significance for Hispanics (OR = 1.41, P = 0.077), but not for other races. For survivors, compared with whites, blacks and Hispanics were less likely to be discharged to a rehabilitation center (OR = 0.68, P < 0.001, and OR = 0.67, P = 0.002, respectively).

CONCLUSIONS

Racial and ethnic disparities exist both in mortality and in discharge to postacute rehabilitation centers among persons with TBI.

Hospital characteristics associated with the management of pediatric splenic injuries

CONTEXT

Despite evidence that more than 90% of children with traumatic injuries to the spleen can be successfully managed nonoperatively, there is significant variation in the use of splenectomy. As asplenic children are at increased risk of overwhelming postsplenectomy infection, nonoperative management may be considered a quality of care indicator.

OBJECTIVE

To test the hypothesis that children are more likely to undergo splenectomy in general hospitals than in children's hospitals.

DESIGN

Retrospective cohort study using data from the Kid's Inpatient Database (KID) for the year 2000. Multivariable regression was used to control for patient and hospital characteristics.

SETTING AND PARTICIPANTS

All children aged 0 to 16 years who were hospitalized with a traumatic (noniatrogenic) spleen injury in nonfederal short-stay hospitals in any of the 27 states participating in KID (N = 2851).

MAIN OUTCOME MEASURE

Splenectomy performed within 1 day of arrival.

RESULTS

A total of 11 children (3%) with splenic injuries receiving care at children's hospitals underwent splenectomy compared with 383 children (15.4%) cared for at general hospitals (P<.001). After adjusting for patient characteristics, injury severity, and hospital characteristics, splenectomy was more likely among children treated at general hospitals (odds ratio, 5.01; 95% confidence interval, 2.21-11.36) than among children treated at children's hospitals.

CONCLUSIONS

There is considerable variation in the management of pediatric splenic injuries, with significantly lower rates of splenectomy at designated children's hospitals. Quality improvement interventions, including increased education and training for physicians in general hospitals, may be needed to increase the use of spleen-conserving management practices.

Results from demineralized bone creep tests suggest that collagen is responsible for the creep behavior of bone

Cortical and trabecular bone have similar creep behaviors that have been described by power-law relationships, with increases in temperature resulting in faster creep damage accumulation according to the usual Arrhenius (damage rate approximately exp (-Temp.-1)) relationship. In an attempt to determine the phase (collagen or hydroxyapatite) responsible for these similar creep behaviors, we investigated the creep behavior of demineralized cortical bone, recognizing that the organic (i.e., demineralized) matrix of both cortical and trabecular bone is composed primarily of type I collagen. We prepared waisted specimens of bovine cortical bone and demineralized them according to an established protocol. Creep tests were conducted on 18 specimens at various normalized stresses sigma/E0 and temperatures using a noninvasive optical technique to measure strain. Denaturation tests were also conducted to investigate the effect of temperature on the structure of demineralized bone. The creep behavior was characterized by the three classical stages of decreasing, constant, and increasing creep rates at all applied normalized stresses and temperatures. Strong (r2 > 0.79) and significant (p < 0.01) power-law relationships were found between the damage accumulation parameters (steady-state creep rate d epsilon/dt and time-to-failure tf) and the applied normalized stress sigma/E0. The creep behavior was also a function of temperature, following an Arrhenius creep relationship with an activation energy Q = 113 kJ/mole, within the range of activation energies for cortical (44 kJ/mole) and trabecular (136 kJ/mole) bone. The denaturation behavior was characterized by axial shrinkage at temperatures greater than approximately 56 degrees C. Lastly an analysis of covariance (ANCOVA) of our demineralized cortical bone regressions with those found in the literature for cortical and trabecular bone indicates than all three tissues creep with the same power-law exponents. These similar creep activation energies and exponents suggest that collagen is the phase responsible for creep in bone.

Creep contributes to the fatigue behavior of bovine trabecular bone

Repetitive, low-intensity loading from normal daily activities can generate fatigue damage in trabecular bone, a potential cause of spontaneous fractures of the hip and spine. Finite element models of trabecular bone (Guo et al., 1994) suggest that both creep and slow crack growth contribute to fatigue failure. In an effort to characterize these damage mechanisms experimentally, we conducted fatigue and creep tests on 85 waisted specimens of trabecular bone obtained from 76 bovine proximal tibiae. All applied stresses were normalized by the previously measured specimen modulus. Fatigue tests were conducted at room temperature; creep tests were conducted at 4, 15, 25, 37, 45, and 53 degrees C in a custom-designed apparatus. The fatigue behavior was characterized by decreasing modulus and increasing hysteresis prior to failure. The hysteresis loops progressively displaced along the strain axis, indicating that creep was also involved in the fatigue process. The creep behavior was characterized by the three classical stages of decreasing, constant, and increasing creep rates. Strong and highly significant power-law relationships were found between cycles-to-failure, time-to-failure, steady-state creep rate, and the applied loads. Creep analyses of the fatigue hysteresis loops also generated strong and highly significant power law relationships for time-to-failure and steady-state creep rate. Lastly, the products of creep rate and time-to-failure were constant for both the fatigue and creep tests and were equal to the measured failure strains, suggesting that creep plays a fundamental role in the fatigue behavior of trabecular bone. Additional analysis of the fatigue strain data suggests that creep and slow crack growth are not separate processes that dominate at high and low loads, respectively, but are present throughout all stages of fatigue.

The tensile behavior of demineralized bovine cortical bone

Bone is frequently modeled as a two-phase composite of hydroxyapatite mineral crystals dispersed throughout an organic collagen matrix. However, because of the numerous limitations (e.g. small sample size, poor strain measuring techniques, rapid demineralization with acids) of previous mechanical tests of bone with its hydroxyapatite chemically removed, we have determined new, accurate data on the material properties of the demineralized bone matrix for use in these composite models. We performed tensile tests on waisted specimens of demineralized bovine cortical bone from six humeral diaphyses. Specimens were demineralized over 14 days with a 0.5 M disodium EDTA solution that was replaced daily. Atomic absorption spectrophotometry was used to track the demineralization process and to determine the effectiveness of our demineralization protocol. Mechanical tests were performed at room temperature under displacement control at an approximate strain rate of 0.5% per s. We imposed nine preconditioning cycles before a final ramp to failure, and measured gauge length displacements using a non-invasive optical technique. The resulting stress-strain curves were similar to the tensile behavior observed in mechanical tests of other collagenous tissues, exhibiting an initial non-linear 'toe' region, followed by a linear region and subsequent failure without evidence of yielding. We found an average modulus, ultimate stress, and ultimate strain of 613 MPa (S.D. = 113 MPa), 61.5 MPa (S.D. = 13.1 MPa), and 12.3% (S.D. = 0.5%), respectively. Our average modulus is approximately half the value frequently used in current composite bone analyses. These data should also have clinical relevance because the early strength of healing fractured bone depends largely on the material properties of the collagen matrix.

Compressive creep behavior of bovine trabecular bone

There are almost no published data that describe the creep behavior of trabecular bone (at the specimen level), even though the creep behavior of cortical bone has been well documented. In an effort to characterize the creep behavior of trabecular bone and to compare it with that of cortical bone, we performed uniaxial compressive creep tests on 24 cylindrical specimens of trabecular bone taken from 19 bovine proximal tibiae. Six different load levels were used, with the applied stress normalized by the specimen modulus measured prior to creep loading. We found that trabecular bone exhibits the three creep regimens (primary, secondary, and tertiary) associated with metals, ceramics, and cortical bone. All specimens eventually fractured at strains less than 3.8%. In addition, the general shape of the creep curve was independent of apparent density. Strong and highly significant power law relationships (r2 > 0.82, p < 0.001) were found between the normalized stress sigma/E0 and both time-to-failure tf and steady-state creep rate d epsilon/dt: tf = 9.66 x 10(-33) (sigma/E0)-16.18; d epsilon/dt = 2.21 x 10(33) (sigma/E0)17.65. These data indicate that the creep behaviors of trabecular and cortical bone are qualitatively similar. In addition, the strength of trabecular bone can be reduced substantially if relatively large stresses (i.e. stresses approximately half the ultimate strength) are applied for 5 h. Such strength reductions may play a role in the etiology of progressive, age-related spine fractures if adaptive bone remodeling does not arrest creep deformations.