Cassandra V. Villegas

Influence of the National Trauma Data Bank on the Study of Trauma Outcomes: Is it Time to Set Research Best Practices to Further Enhance Its Impact?

BACKGROUND Risk-adjusted analyses are critical in evaluating trauma outcomes. The National Trauma Data Bank (NTDB) is a statistically robust registry that allows such analyses; however, analytical techniques are not yet standardized. In this study, we examined peer-reviewed manuscripts published using NTDB data, with particular attention to characteristics strongly associated with trauma outcomes. Our objective was to determine if there are substantial variations in the methodology and quality of risk-adjusted analyses and therefore, whether development of best practices for risk-adjusted analyses is warranted. STUDY DESIGN A database of all studies using NTDB data published through December 2010 was created by searching PubMed and Embase. Studies with multivariate risk-adjusted analyses were examined for their central question, main outcomes measures, analytical techniques, covariates in adjusted analyses, and handling of missing data. RESULTS Of 286 NTDB publications, 122 performed a multivariable adjusted analysis. These studies focused on clinical outcomes (51 studies), public health policy or injury prevention (30), quality (16), disparities (15), trauma center designation (6), or scoring systems (4). Mortality was the main outcome in 98 of these studies. There were considerable differences in the covariates used for case adjustment. The 3 covariates most frequently controlled for were age (95%), Injury Severity Score (85%), and sex (78%). Up to 43% of studies did not control for the 5 basic covariates necessary to conduct a risk-adjusted analysis of trauma mortality. Less than 10% of studies used clustering to adjust for facility differences or imputation to handle missing data. CONCLUSIONS There is significant variability in how risk-adjusted analyses using data from the NTDB are performed. Best practices are needed to further improve the quality of research from the NTDB.

Racial, Ethnic, and Insurance Status Disparities in Use of Posthospitalization Care after Trauma

BACKGROUND Posthospitalization care is important for recovery after trauma. Disadvantaged populations, like racial or ethnic minorities and the uninsured, make up substantial percentages of trauma patients, but their use of posthospitalization facilities is unknown. STUDY DESIGN This study analyzed National Trauma Data Bank admissions from 2007 for 18- to 64-year-olds and estimated relative risk ratios (RRR) of discharge to posthospitalization facilities--home, home health, rehabilitation, or nursing facility--by race, ethnicity, and insurance. Multinomial logistic regression adjusted for patient characteristics including age, sex, Injury Severity Score, mechanism of injury, and length of stay, among others. RESULTS There were 136,239 patients who met inclusion criteria with data for analysis. Most patients were discharged home (78.9%); fewer went to home health (3.3%), rehabilitation (5.0%), and nursing facilities (5.4%). When compared with white patients in adjusted analysis, relative risk ratios of discharge to rehabilitation were 0.61 (95% CI 0.56, 0.66) and 0.44 (95% CI 0.40, 0.49) for blacks and Hispanics, respectively. Compared with privately insured white patients, Hispanics had lower rates of discharge to rehabilitation whether privately insured (RRR 0.45, 95% CI 0.40, 0.52), publicly insured (RRR 0.51, 95% CI 0.42, 0.61), or uninsured (RRR 0.20, 95% CI 0.17, 0.24). Black patients had similarly low rates: private (RRR 0.63, 95% CI 0.56, 0.71), public (RRR 0.72, 95% CI 0.63, 0.82), or uninsured (RRR 0.27, 95% CI 0.23, 0.32). Relative risk ratios of discharge to home health or nursing facilities showed similar trends among blacks and Hispanics regardless of insurance, except for black patients with insurance whose discharge to nursing facilities was similar to their white counterparts. CONCLUSIONS Disadvantaged populations have more limited use of posthospitalization care such as rehabilitation after trauma, suggesting a potential improvement in trauma care for the underprivileged.

Outcome of selective non-operative management of penetrating abdominal injuries from the North American National Trauma Database

The aim of this study was to investigate trends in the practice of selective non‐operative management (SNOM) for penetrating abdominal injury (PAI) and to determine factors associated with its failure.

Pedestrians struck by motor vehicles further worsen race- and insurance-based disparities in trauma outcomes: the case for inner-city pedestrian injury prevention programs.

BACKGROUND Pedestrian trauma is the most lethal blunt trauma mechanism, and the rate of mortality in African Americans and Hispanics is twice that compared with whites. Whether insurance status and differential survival contribute to this disparity is unknown. METHODS This study is a review of vehicle-struck pedestrians in the National Trauma Data Bank, v7.0. Patients <16 years and > or =65 years, as well as patients with Injury Severity Score (ISS) <9, were excluded. Patients were categorized as white, African American, or Hispanic, and as privately insured, government insured, or uninsured. With white and privately insured patients as reference, logistic regression was used to evaluate mortality by race and insurance status after adjusting for patient and injury characteristics. RESULTS In all, 26,404 patients met inclusion criteria. On logistic regression, African Americans had 22% greater odds of mortality (odds ratio [OR], 1.22; 95% confidence interval [CI], 1.06-1.41) and Hispanics had 33% greater odds of mortality (OR, 1.33; 95% CI, 1.14-1.54) compared with whites. Uninsured patients had 77% greater odds of mortality (OR, 1.77; 95% CI, 1.52-2.06) compared with privately insured patients. CONCLUSION African American and Hispanic race, as well as uninsured status, increase the risk of mortality after pedestrian crashes. Given the greater incidence of pedestrian crashes in minorities, this compounded burden of injury mandates pedestrian trauma prevention efforts in inner cities to decrease health disparities.

Validating the Injury Severity Score (ISS) In Different Populations: ISS Predicts Mortality Better Among Hispanics and Females

INTRODUCTION The Injury Severity Score (ISS) is the most commonly used measure of injury severity. The score has been shown to have excellent predictive capability for trauma mortality and has been validated in multiple data sets. However, the score has never been tested to see if its discriminatory ability is affected by differences in race and gender. OBJECTIVE This study is aimed at validating the ISS in men and women and in three different race/ethnic groups using a nationwide database. METHODS Retrospective analysis of patients age 18-64 y in the National Trauma Data Bank 7.0 with blunt trauma was performed. ISS was categorized as mild (<9,) moderate (9-15), severe (16-25), and profound (>25). Logistic regression was done to measure the relative odds of mortality associated with a change in ISS categories. The discriminatory ability was compared using the receiver operating characteristics curves (ROC). A P value testing the equality of the ROC curves was calculated. Age stratified analyses were also conducted. RESULTS A total of 872,102 patients had complete data for the analysis on ethnicity, while 763,549 patients were included in the gender analysis. The overall mortality rate was 3.7%. ROC in Whites was 0.8617, in Blacks 0.8586, and in Hispanics 0.8869. Hispanics have a statistically significant higher ROC (P value < 0.001). Similar results were observed within each age category. ROC curves were also significantly higher in females than in males. CONCLUSION The ISS possesses excellent discriminatory ability in all populations as indicated by the high ROCs.

Motorcycle Helmets Associated with Lower Risk of Cervical Spine Injury: Debunking the Myth

BACKGROUND There has been a repeal of the universal helmet law in several states despite definitive evidence that helmets reduce mortality, traumatic brain injury, and hospital expenditures. Opponents of the universal helmet law have successfully claimed that helmets should not be required because of greater torque on the neck, which is thought to increase the likelihood of a cervical spine injury. There is currently insufficient evidence to counter claims that helmets do not increase the risk of cervical spine injury after a motorcycle collision. The objective of this study was to determine the impact of motorcycle helmets on the likelihood of developing a cervical spine injury after a motorcycle collision. STUDY DESIGN We reviewed cases in the National Trauma Databank (NTDB) v7.0 involving motorcycle collisions. Multiple logistic regression was used to analyze the independent effect of helmets on cervical spine injury. Cases were adjusted for age, race, sex, insurance status, anatomic (Injury Severity Score) and physiologic injury severity (systolic blood pressure < 90 mmHg), and head injury (Abbreviated Injury Score > 3). RESULTS Between 2002 and 2006, 62,840 cases of motorcycle collision were entered into the NTDB; 40,588 had complete data and were included in the adjusted analysis. Helmeted riders had a lower adjusted odds (0.80 [CI 0.72 to 0.90]) and a lower proportion of cervical spine injury (3.5% vs 4.4%, p < 0.05) compared with nonhelmeted riders. CONCLUSIONS Helmeted motorcyclists are less likely to suffer a cervical spine injury after a motorcycle collision. This finding challenges a long-standing objection to mandatory helmet use that claims helmets are associated with cervical spine injury. Re-enactment of the universal helmet law should be considered in states where it has been repealed.

Mechanism of injury predicts case fatality and functional outcomes in pediatric trauma patients: The case for its use in trauma outcomes studies

BACKGROUND/PURPOSE The mechanism of injury (MOI) may serve as a useful adjunct to injury scoring systems in pediatric trauma outcomes research. The objective is to determine the independent effect of MOI on case fatality and functional outcomes in pediatric trauma patients. METHODS Retrospective review of pediatric patients ages 2 to 18 years in the National Trauma Data Bank from 2002 through 2006 was done. Mechanism of injury was classified by the International Classification of Diseases, Ninth Revision, E codes. The main outcome measures were mortality, discharge disposition (home vs rehabilitation setting), and functional impairment at hospital discharge. Multiple logistic regression was used to adjust for injury severity (using the Injury Severity Score and the presence of shock upon admission in the emergency department), age, sex, and severe head or extremity injury. RESULTS Thirty-five thousand ninety-seven pediatric patients in the National Trauma Data Bank met inclusion criteria. Each MOI had differences in the adjusted odds of death or functional disabilities as compared with the reference group (fall). The MOI with the greatest risk of death was gunshot wounds (odds ratio [OR], 3.52; 95% confidence interval [CI], 2.23-5.54 95). Pediatric pedestrians struck by a motor vehicle have the highest risk of locomotion (OR, 3.30; 95% CI, 2.89-3.77) and expression (OR, 1.65; 95% CI, 1.22-2.23) disabilities. CONCLUSION Mechanism of injury is a significant predictor of clinical and functional outcomes at discharge for equivalently injured patients. These findings have implications for injury prevention, staging, and prognosis of traumatic injury and posttreatment planning.

Predictors of sepsis in moderately severely injured patients: an analysis of the National Trauma Data Bank

BACKGROUND Post-traumatic sepsis is a significant cause of in-hospital death. However, socio-demographic and clinical characteristics that may predict sepsis in injured patients are not well known. The objective of this study was to identify risk factors that may be associated with post-traumatic sepsis. METHODS Retrospective analysis of patients in the National Trauma Data Bank for 2007-2008. Patients older than 16 years of age with an Injury Severity Score (ISS) ≥ 9 points were included. Multivariable logistic regression was used to determine association of sepsis with patient (age, gender, ethnicity, and insurance status), injury (mechanism, ISS, injury type, hypotension), and clinical (major surgical procedure, intensive care unit admission) characteristics. RESULTS Of a total of 1.3 million patients, 373,370 met the study criteria, and 1.4% developed sepsis, with an associated mortality rate of approximately 20%. Age, male gender, African-American race, hypotension on emergency department presentation, and motor vehicle crash as the injury mechanism were independently associated with post-traumatic sepsis. CONCLUSIONS Socio-demographic and injury factors, such as age, race, hypotension on admission, and severity and mechanism of injury predict post-traumatic sepsis significantly. Further exploration to explain why these patient groups are at increased risk is warranted in order to understand better and potentially prevent this life-threatening complication.

Should the IDC-9 Trauma Mortality Prediction Model become the new paradigm for benchmarking trauma outcomes?

BACKGROUND Optimum quantification of injury severity remains an imprecise science with a need for improvement. The accuracy of the criterion standard Injury Severity Score (ISS) worsens as a patient’s injury severity increases, especially among patients with penetrating trauma. The objective of this study was to comprehensively compare the mortality prediction ability of three anatomic injury severity indices: the ISS, the New ISS (NISS), and the DRG International Classification of Diseases—9th Rev.—Trauma Mortality Prediction Model (TMPM-ICD-9), a recently developed contemporary injury assessment model. METHODS Retrospective analysis of patients in the National Trauma Data Bank from 2007 to 2008. The TMPM-ICD-9 values were computed and compared with the ISS and NISS for each patient using in-hospital mortality after trauma as the outcome measure. Discrimination and calibration were compared using the area under the receiver operator characteristic curve. Subgroup analysis was performed to compare each score across varying ranges of injury severity and across different types of injury. RESULTS A total of 533,898 patients were identified with a crude mortality rate of 4.7%. The ISS and NISS performed equally in the groups with minor (ISS, 1–8) and moderate (ISS, 9–15) injuries, regardless of the injury type. However, in the populations with severe (ISS, 16–24) and very severe (ISS, ≥25) injuries for all injury types, the NISS predicted mortality better than the ISS did. The TMPM-ICD-9 outperformed both the NISS and ISS almost consistently. CONCLUSION The NISS and TMPM-ICD-9 are both superior predictors of mortality as compared with the ISS. The immediate adoption of NISS for evaluating trauma outcomes using trauma registry data is recommended. The TMPM-ICD-9 may be an even better measure of human injury, and its use in administrative or nonregistry data is suggested. Further research on its attributes is recommended because it has the potential to become the basis for benchmarking trauma outcomes. LEVEL OF EVIDENCE Prognostic study, level III.

Association between intentional injury and long-term survival after trauma

Objective:To determine the risk-adjusted mortality of intentionally injured patients within 7 to 9 years postinjury, compared with unintentionally injured patients. Background:Violent injury contributes significantly to trauma mortality in the United States. Homicide is the second leading killer of American youth, aged 15 to 24 years. Long-term survival among intentionally injured patients has not been well studied. It is also unknown whether intentionally injured patients have worse long-term survival compared with unintentionally or accidentally injured patients with equivalent injuries. Methods:Adult trauma patients admitted for 24 hours or more and discharged alive from the Johns Hopkins Hospital from January 1, 1998, to December 31, 2000, were included. The primary outcome was mortality within 7 to 9 years postinjury. Long-term patient survival was determined using the National Death Index. The association between injury intentionality and mortality was investigated using a Cox proportional hazard regression model, adjusted for confounders such as injury severity and patient race, socioeconomic status, and comorbid conditions. Overall differences in survival between those with intentional versus unintentional injury were also determined by comparing adjusted Kaplan-Meier survival curves. Results:A total of 2062 patients met inclusion criteria. Of these, 56.4% were intentionally injured and 43.6% were unintentionally injured. Compared with unintentionally injured patients, intentionally injured patients were younger and more often male and from a zip code with low median household income. Approximately 15% of all patients had died within 7 to 9 years of follow-up. Older age and presence of comorbidities were associated with this outcome; however, intentional injury was not found to be significantly associated with long-term mortality rates. There was also no significant difference in survival curves between groups; intentionally injured patients were much more likely to die of a subsequent injury, whereas those with unintentional injury commonly died of noninjury causes. Conclusions:There was no significant difference in mortality between intentionally injured and unintentionally injured patients within 7 to 9 years postinjury. These results confirm the long-term effectiveness of lifesaving trauma care for those with intentional injury. However, given that patients with intentional injuries were more likely to suffer a subsequent violent death, interventions focused on breaking the cycle of violence are needed.