Evaluation of the Statewide Variability in the Current Role of Different Specialties in Lower Extremity Endovascular Revascularization for Medicare Beneficiaries.

PURPOSE: To evaluate the statewide variability in the role of different specialties in lower extremity endovascular revascularization (LEER) and associated submitted charges of care and actual reimbursement for Medicare beneficiaries. METHODS: The 2015 "Medicare Provider Utilization and Payment Data: Physician and Other Supplier" data includes provider-specific information regarding the type of service, submitted average charges of care, and actual average Medicare reimbursements per Healthcare Common Procedure Coding System (HCPCS) code per provider. All HCPCS codes related to LEER were identified. The role of vascular surgery (VS), interventional cardiology (IC), and interventional radiology (IR) in each HCPCS-specific intervention was investigated. RESULTS: In 2015, 4113 providers submitted claims for iliac (n = 13,659), femoropopliteal (n = 52,344), and tibioperoneal (n = 32,688) endovascular revascularizations. In the facility setting, VS performed most of these procedures (52%), followed by IC (32%) and IR (8%). In the outpatient-based lab setting, the proportions were 46%, 36%, and 13%, respectively. Substantial statewide variability in the role of different specialties in LEER was noted. In Maine, Vermont, and Hawaii, all facility claims were submitted by VS, while more than 70% of the claims in Arizona and Utah were submitted by IC. The highest share of LEER for IR was observed in Montana and North Dakota (50%). There was substantial statewide variability in the submitted charges. CONCLUSION: Currently, less than 10% of LEER procedures are being performed by IR. The statewide variability in the submitted charges of care by providers and actual reimbursement for Medicare beneficiaries were investigated in this study.

Introduction to Cost Analysis in IR: Challenges and Opportunities.

Demonstration of value has become increasingly important in the current health care system. This review summarizes four of the most commonly used cost analysis methods relevant to IR that could be adopted to demonstrate the value of IR interventions: the cost minimization study, cost-effectiveness assessment, cost-utility analysis, and cost-benefit analysis. In addition, the issues of true cost versus hospital charges, modeling in cost studies, and sensitivity analysis are discussed.

Digital pressure and oxygen saturation measurements in the diagnosis of chronic hemodialysis access-induced distal ischemia.

OBJECTIVE: Hemodialysis access-induced distal ischemia (HAIDI) can be classified as acute (on the first postoperative day), subacute (≤1 month), or chronic (>1 month), based on the time of onset after access creation. The diagnosis is mainly clinical. However, performing additional tests is beneficial in further assessment of patients. The purpose of this study was to evaluate the use of finger pressure and oxygen saturation measurements for the diagnosis of chronic HAIDI. METHODS: A total of 20 patients with chronic HAIDI (cases) and 40 asymptomatic hemodialysis patients (controls) were matched for age, sex, etiology of end-stage renal disease, and type of arteriovenous access. Basal digital pressure (BDP), digital pressure during manual compression of access, digital brachial index (DBI), change in digital pressure with access compression (CDP), digital pressure of the contralateral side, and bilateral oxygen saturation (O2 Sat) were measured in all patients. RESULTS: In the case group, compression of the arteriovenous fistula (AVF) increased mean BDP from 61 ± 26 to 118 ± 28 mm Hg (P < .001), which failed to reach the non-AVF side mean digital pressure of 151 ± 25 mm Hg (P < .001). In addition, O2 Sat of the AVF side was significantly lower than the contralateral side (92.9% ± 2.1% vs 95.6% ± 1.4%; P = .001). Among the controls, manual AVF compression raised the mean BDP from 114 ± 36 mm Hg to 133 ± 29 mm Hg (P < .001), which was still significantly lower than the contralateral side mean digital pressure of 141 ± 30 mm Hg (P = .002). In addition, O2 Sat values of the two sides were different (96.7% ± 2.1% vs 97.1% ± 1.9%; P = .01). Comparing the cases and controls, the mean BDP (61 ± 26 mm Hg vs 114 ± 36 mm Hg; P < .001), DBI (0.44 ± 0.16 vs 0.82 ± 0.19; P < .001), and O2 Sat (92.9% ± 2.1% vs 96.7% ± 2.1%; P < .001) were significantly lower and CDP (57 ± 24 mm Hg vs 19 ± 17 mm Hg; P < .001) was significantly higher in the cases than in the controls. The optimal discriminatory thresholds of 80 mm Hg for BDP, 0.7 for DBI, 40 mm Hg for CDP, and 94% for O2 Sat were determined. CONCLUSIONS: Digital pressure and O2 Sat measurements are useful additional methods to assist in the clinical evaluation of hemodialysis patients with access-related hand ischemia. BDP <80 mm Hg, DBI <0.7, CDP >40 mm Hg, and O2 Sat <94% are associated with chronic HAIDI.

Superselective yttrium-90 radioembolization for hepatocellular carcinoma yields high response rates with minimal toxicity.

PURPOSE: To assess the safety and efficacy of yttrium-90 ((90)Y) radioembolization when performed in a superselective fashion for patients with unresectable hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This retrospective study included 20 patients with unresectable HCC. Median Model for End-Stage Liver Disease score was 10.5 (range, 6-25), with 8 of 20 patients (40%) classified Child-Pugh class B and 1 of 20 patients (5%) classified class C cirrhosis. Segmental tumor-associated portal vein thrombus was present in 12 patients (60%), and a transjugular intrahepatic portosystemic shunt was present in 4 patients (20%). Median tumor diameter was 3.9 cm (range, 2.5-7.1 cm). All patients underwent superselective (90)Y radioembolization targeted to a single liver segment using glass microspheres. RESULTS: Median dose to the treated segment was 254 Gy, and median dose to the tumor was 536 Gy. No grade 3-4 hepatotoxicity occurred. The most common clinical toxicities were fatigue (30%), abdominal pain (10%), and postembolization syndrome (10%). Follow-up imaging demonstrated complete European Association for the Study of the Liver response of the index tumor in 19 of 20 patients (95%) and stable disease in 1 of 20 patients (5%). In patients with complete response, local tumor recurrence rate was 5.3% (1 of 19 patients). Median time to progression was 319 days. Overall survival was 90% (18 of 20 patients) with a median follow-up period of 275 days (range, 32-677 d). CONCLUSIONS: When performed in a segmental fashion, (90)Y radioembolization demonstrates high response rates and low local tumor recurrence rates. Complete imaging response can be achieved in patients with locally aggressive disease. This study demonstrates no clinically significant hepatotoxicity, despite moderate liver dysfunction in many patients.

Biostatistics primer for the radiologist.

OBJECTIVE: The purpose of this article is to review the most common data analysis methods encountered in radiology-based studies. Initially, description of variable types and their corresponding summary measures are provided; subsequent discussion focuses on comparison of these summary measures between groups, with a particular emphasis on regression analysis. CONCLUSION: Knowledge of statistical applications is critical for radiologists to accurately evaluate the current literature and to conduct scientifically rigorous studies. Misapplication of statistical methods can lead to inappropriate conclusions and clinical recommendations.

Utilization of angiography and embolization for abdominopelvic trauma: 14 years' experience at a level I trauma center.

OBJECTIVE: The objective of our study was to evaluate the long-term trends in the use of angiography and embolization for abdominopelvic injuries. MATERIALS AND METHODS: Utilization rates for pelvic and abdominal angiography, arterial embolization, and CT were analyzed for trauma patients with pelvic fractures and liver and kidney injuries admitted to a level 1 trauma center from 1996 to 2010. Multivariable linear regression was used to evaluate trends in the use of angioembolization. RESULTS: A total of 9145 patients were admitted for abdominopelvic injuries during the study period. Pelvic angiography decreased annually by 5.0% (95% CI, -6.4% to -3.7%) from 1996 to 2002 and by 1.8% (-2.4% to -1.2%) from 2003 to 2010. Embolization rates for these patients varied from 49% in 1997 to 100% in 2010. Utilization of pelvic CT on the day of admission increased significantly during this period. Abdominal angiography for liver and kidney injuries decreased annually by 3.3% (95% CI, -4.8% to -1.8%) and 2.0% (-4.3% to 0.3%) between 1996 and 2002 and by 0.8% (95% CI, -1.4% to -0.1%) and 0.9% (-2.0% to 0.1%) from 2003 to 2010, respectively. Embolization rates ranged from 25% in 1999 to 100% in 2010 for liver injuries and from 0% in 1997 to 80% in 2002 for kidney injuries. Abdominal CT for liver and kidney injuries on the day of admission also increased. CONCLUSION: A significant decrease in angiography use for trauma patients with pelvic fractures, liver injuries, and kidney injuries from 1996 to 2010 and a trend toward increasing embolization rates among patients who underwent angiography were found. These findings reflect a declining role of angiography for diagnostic purposes and emphasize the importance of angiography as a means to embolization for management.

CT use in hospitalized pediatric trauma patients: 15-year trends in a level I pediatric and adult trauma center.

PURPOSE: To evaluate the 15-year trend in the use of computed tomography (CT) in hospitalized pediatric trauma patients admitted to Harborview Medical Center (HMC) from 1996 to 2010. MATERIALS AND METHODS: This Health Insurance Portability and Accountability Act-compliant retrospective study was approved by the institutional review board. The requirement for informed consent was waived. The HMC trauma registry was linked to the billing department data, and patient and injury-related characteristics were extracted, in addition to type and frequency of CT procedures. Patients discharged from the emergency department and patients hospitalized for less than 24 hours were not included in this study. Patients were classified into three categories according to age: 0-14 years, 15-18 years, and 19-54 years (reference group). Multivariate negative binomial regression was used to compare CT usage among different age groups by adjusting for patient sex, race and/or ethnicity, insurance status, mechanism of injury, injury severity, final disposition (dead vs alive), and year of admission. The trend for CT use in children and teenagers was also evaluated. RESULTS: A total of 64 425 trauma patients 0-54 years of age were admitted during the study period. Compared with CT usage in adults 19-54 years old, usage in children up to 15 years of age was significantly lower for spine (incidence rate ratio [IRR], 0.89; 95% confidence interval [CI]: 0.85, 0.92), maxillofacial (IRR, 0.89; 95% CI: 0.81, 0.97), and thoracic (IRR, 0.91; 95% CI: 0.84, 0.99) CT. Increased use of head CT was observed in children up to 15 years old (IRR, 1.09; 95% CI: 1.05, 1.13) and 15-18 years old (IRR, 1.08; 95% CI: 1.04, 1.13). From 2008 to 2010, usage rates in children up to 15 years old and 15-18 years old was relatively unchanged or slightly decreased for almost all CT types. CONCLUSION: A decreasing or unchanged trend was observed in CT usage in hospitalized pediatric trauma patients in recent years. © RSNA, 2013.

Accuracy of Medical Student Measurements of CT Right-to-Left Ventricular Diameter in Patients with Acute Pulmonary Embolism.

Objectives: Acute pulmonary embolism (PE) is a common disease, necessitating risk stratification to determine management. A right ventricle (RV) to left ventricle (LV) diameter ratio ≥1.0 on computed tomography pulmonary angiography (CTPA) suggests RV strain, which may indicate a worse prognosis. Two prior studies showed that residents with brief training by a radiologist could accurately measure RV/LV ratio. We assessed whether medical students could accurately measure RV dilatation. Methods: We conducted a post hoc analysis of a retrospective cohort study of adults undergoing management for acute PE at 21 community emergency departments across Kaiser Permanente Northern California from 2013 to 2015. We created a sample, stratified to contain an equal number of patients from each of the 5 PE Severity Index classes. Four medical students measured RV and LV diameter on CTPA after training from an emergency medicine physician and an interventional radiologist. We used Cohen's kappa statistics, Bland-Altman plots, and Pearson correlation coefficients to assess interrater reliability. Results: Of the 108 CTPAs reviewed, 79 (73%) showed RV dilatation and 29 (27%) did not. The kappa statistic for the presence of RV dilatation of the medical students compared to the radiologist showed moderate agreement for 3 medical students (kappa (95% CI): 0.46 (0.21-0.70), 0.49 (0.31-0.68), 0.50 (0.32-0.68)) and fair agreement for 1 medical student (kappa (95% CI): 0.29 (0.10-0.47)). The average interrater differences in RV/LV ratio between a radiologist and each of the 4 medical students were -0.04, -0.05, 0.04, and 0.24. Pearson correlation coefficients were 0.87, 0.80, 0.74, and 0.78, respectively, indicating moderate correlation (P < .001 for all). Conclusion: Medical students were able to identify RV dilatation on CTPA in moderate agreement with that of a radiologist. Further study is needed to determine whether medical student accuracy could improve with additional training.

Falls, older adults, and the trend in utilization of CT in a level I trauma center.

OBJECTIVE: The purpose of this article is to evaluate the trend in the utilization of CT for fall victims older than 55 years admitted to a level I trauma center. MATERIALS AND METHODS: We used trauma registry data (1996-2006) of a level I trauma center. By using the International Classification of Disease, Ninth Revision (Clinical Modification) codes, we identified the type and frequency of CT examinations for each patient. We used negative binomial regression to evaluate the association between CT utilization rates and age, year of admission, sex, insurance status, ethnicity, ICU admission status, injury severity score, and final disposition (i.e., deceased vs alive). We used logistic regression to evaluate predictors of repeat (i.e., ≥ 2) CT scans. RESULTS: During the study period, the utilization rate of head, abdomen, thorax, and other body region (including spine and extremities) CT examinations increased, on average, by 7%, 16%, 14%, and 15% per year, respectively. Older age was associated with a higher utilization of head CT. Male sex and ICU admission were associated with higher utilization for all types of CT examinations. Repeat head and abdominal CT scans increased, on average, by 28% (95% CI, 20-36%) and 24% (95% CI, 2-51%) per year, respectively. CONCLUSION: We quantified the increase in utilization rates of all types of CT scans for fall victims admitted to a level I trauma center. We found a marked increase in CT use over time, both for initial as well as repeat studies, and an association between CT use and variables such as sex. Future studies should focus on the evaluation of CT appropriateness and their influence on patient outcomes.

Burden of alcohol-related injuries on radiology services at a level I trauma center.

OBJECTIVE: The purpose of our study was to evaluate the burden of alcohol-related injuries on a radiology department at a level 1 trauma center. MATERIALS AND METHODS: We linked the trauma registry (2005-2009) of Harborview Medical Center to billing department data and extracted patient demographic and injury-related characteristics and the radiology services provided. Multivariate negative binomial analysis was used to evaluate the association between blood alcohol concentration (BAC) and CT and MRI utilization rates. RESULTS: A total of 125,776 CT and 4681 MRI examinations were performed on 27,274 patients during the study period. Higher BAC was generally associated with higher utilization rates for all types of CT even after adjusting for potential confounding variables. Compared with patients with a BAC of 0, the greatest increases in utilization were observed in individuals with a BAC of 240 mg/dL or more for head CT (incidence rate ratio [IRR], 1.43; 95% CI, 1.32-1.54), cervical spine (IRR, 1.45; 95% CI, 1.32-1.58), and maxillofacial (IRR, 1.66; 95% CI, 1.42-1.95), with no increase observed for MRI. This association was more prominent in less severely injured patients with utilization rates for head CT (IRR, 1.83; 95% CI, 1.56-2.13), abdomen (IRR, 1.46; 95% CI, 1.32-1.63), and thorax (IRR, 1.57; 95% CI, 1.30-1.89) in individuals with a BAC of 240 mg/dL or more compared with those with a BAC of 0. CONCLUSION: Higher BAC was associated with increased CT utilization for most body region-specific CT scans and was more strongly associated in patients with less severe injuries. Any guideline that could potentially decrease unnecessary imaging for patients with alcohol-involved injuries would represent a cost-saving strategy.

Lumbar spine MRI for low back pain: indications and yield.

OBJECTIVE: Low back pain is one of the most common causes of physician visits in the United States with an enormous socioeconomic burden. Because of this burden, numerous studies have focused on its diagnosis and management. New technologies have been quickly adopted with the hope that they will improve our understanding of the physiopathology of the disease and assist us in alleviating patients' pain and discomfort. Unfortunately, previous studies have not been able to show that higher utilization of advanced imaging technology is associated with improvements in patient outcome. This article highlights practices that are evidence-based versus those that are common, or heterogeneous, but not supported by existing evidence. We also highlight outstanding areas for further research. CONCLUSION: Clinicians and researchers should be encouraged to follow standardized practices in accordance with evidence-based medicine guidelines. The use of such guidelines will decrease variation in care, allowing researchers to more easily design and conduct comparative effectiveness studies of diagnostic imaging.

Computational Modeling of the Liver Arterial Blood Flow for Microsphere Therapy: Effect of Boundary Conditions.

Transarterial embolization is a minimally invasive treatment for advanced liver cancer using microspheres loaded with a chemotherapeutic drug or radioactive yttrium-90 (90Y) that are injected into the hepatic arterial tree through a catheter. For personalized treatment, the microsphere distribution in the liver should be optimized through the injection volume and location. Computational fluid dynamics (CFD) simulations of the blood flow in the hepatic artery can help estimate this distribution if carefully parameterized. An important aspect is the choice of the boundary conditions imposed at the inlet and outlets of the computational domain. In this study, the effect of boundary conditions on the hepatic arterial tree hemodynamics was investigated. The outlet boundary conditions were modeled with three-element Windkessel circuits, representative of the downstream vasculature resistance. Results demonstrated that the downstream vasculature resistance affected the hepatic artery hemodynamics such as the velocity field, the pressure field and the blood flow streamline trajectories. Moreover, the number of microspheres received by the tumor significantly changed (more than 10% of the total injected microspheres) with downstream resistance variations. These findings suggest that patient-specific boundary conditions should be used in order to achieve a more accurate drug distribution estimation with CFD in transarterial embolization treatment planning.

Do minority or white patients respond to brief alcohol intervention in trauma centers? A randomized trial.

STUDY OBJECTIVE: The current study evaluates whether the effectiveness of brief alcohol intervention in reducing 6- and 12-month risk of injuries in a large Level I urban trauma center varies according to trauma patients' ethnicity. METHODS: Eligible white, Hispanic, and black trauma patients aged 18 years or older were randomized to brief alcohol intervention or treatment as usual. The intervention was a "non-confrontational, patient-centered conversation" focused on patients' drinking pattern, with the purpose of encouraging them to change risky drinking. Study outcomes were patient-reported 6- and 12-month incidence of all-type injuries, alcohol-related injuries, and serious injuries (ie, injuries requiring emergency department visit or hospital admission). RESULTS: A total of 1,493 trauma patients (668 whites, 537 Hispanics, 288 blacks) participated in this study. After 1 year of follow-up, we were not able to detect any important association between brief intervention and the risk of all-type injuries, alcohol-related injuries, or serious injuries among study participants. In addition, the association between brief intervention and the outcomes of interest was not modified by patients' ethnicity. CONCLUSION: Our study, congruent with some recent publications, implies that there are some patient- and provider-related impediments that could restrict the effectiveness of brief intervention programs in trauma centers, regardless of patient ethnicity. Unless those impediments are identified and eliminated, assuming that brief intervention will be an effective strategy for controlling future alcohol-related injuries among trauma patients and should be provided under any circumstances might not be reasonable.

Correlates of protective behavior utilization among heavy-drinking college students.

Previous studies have suggested that college students who use protective strategies while drinking are at a lower risk for drinking-related consequences. This study evaluated the correlates of protective behavior utilization in a group of 281 heavy-drinking college students. Students who reported heavier drinking were less likely to use protective behaviors, even after adjusting for covariates. Male gender and perceived history of parental alcohol abuse also predicted lower protective behavior score. The most frequently endorsed strategies among females were "Knowing where your drink has been at all times" and "Going home with a friend," whereas the most frequently endorsed strategies among males were "Knowing where your drink has been at all times" and "Using a designated driver." For females, the factor structure of the protective behaviors measure was consistent with previous studies; however, for males, the results suggest a four-factor solution. Findings are discussed in terms of their implications on future research and prevention programming.

Comparison of mid-block and intersection-related left turn collisions.

OBJECTIVES: To evaluate the factors that might influence an occupant's injury severity during a left turn movement. METHODS: We used the National Automotive Sampling System Crashworthiness Data System (1995-2005) to compare crash characteristics and injury outcome between intersection and midblock left turn collisions. RESULTS: A total of 7,396 collisions were evaluated. Traffic control devices were present in 82% of intersection and 10% of mid-block collisions. After adjustment for potential confounding variables, drivers' injury severity was not significantly associated with the crash location. However, front seat passengers in mid-block collisions had 72% higher odds of experiencing an injury with injury severity score > or =9 (odds ratio: 1.72, 95% confidence interval: 1.09-2.69). Our analysis did not show that drivers or passengers in larger vehicles, e.g., sport utility vehicles and mini-vans, were at lower risk of more severe injuries in comparison to the car occupants in sedans. CONCLUSION: We found that in comparison to intersection-related left turn collisions, mid-block crashes are associated with more severe injuries for front seat passengers. Furthermore, size of the turning vehicle was not significantly associated with injury severity for drivers or front seat passengers.

Childhood trauma fatality and resource allocation in injury control programs in a developing country.

BACKGROUND: Only a few studies have addressed the trimodal distribution of childhood trauma fatalities in lesser developed countries. We conducted this study to evaluate pre-hospital, Emergency Department (ED) and in-hospital distribution of childhood injury-related death for each mechanism of injury in Tehran, Iran. This information will be used for the efficient allocation of the limited injury control resources in the city. METHODS: We used Tehran's Legal Medicine Organization (LMO) database. This is the largest and the most complete database that receives information about trauma fatalities from more than 100 small and large hospitals in Tehran. We reviewed all the medical records and legal documents of the deceased registered in LMO from September 1999 to September 2000. Demographic and injury related characteristics of the children 15 years old or younger were extracted from the records. RESULTS: Ten percent of the 4,233 trauma deaths registered in LMO occurred among children 15 years old or younger. Motor vehicle crashes (MVCs) (50%), burns (18%), falls (6%) and poisonings (6%) were the most common mechanisms of unintentional fatal injuries. Prehospital, emergency department and hospital deaths comprised 42%, 20% and 37% of the trauma fatalities, respectively. While, more than 80% of fatal injuries due to poisoning and drowning occurred in prehospital setting, 92% of burn-related fatalities happened after hospital admission. CONCLUSION: Injury prevention is the single most important solution for controlling trauma fatalities due to poisoning and drowning. Improvements in the quality of care in hospitals and intensive care units might substantially alleviate the magnitude of the problem due to burns. Improvements in prehospital and ED care might significantly decrease MVC and falls-related fatalities.

Turning at intersections and pedestrian injuries.

OBJECTIVE: To evaluate if precrash vehicle movement is associated with the severity of pedestrian injury. METHODS: We used comprehensive information on pedestrian, vehicle, and injury-related characteristics gathered in the Pedestrian Crash Data Study (PCDS), conducted by the National Highway Traffic Safety Administration (NHTSA) (1994-1998). The odds ratio of severe injuries (injury severity score >/= 15) and crash fatality rate for right- and left-turn collisions at intersection compared with straight vehicle movement were compared using a logistic regression model and taking into consideration the type of vehicle and age of the pedestrians as potential effect modifiers. Later we evaluated the intermediate effect of impact speed on the association by adding it to the logistic regression model. RESULTS: Of 255 collisions eligible for this analysis, the proportion of pedestrian hit during straight movement, right turns, and left turns were 48%, 32%, and 10%, respectively. Sixty percent of the pedestrians in left-turn crashes and 67% of them in right-turn collisions were hit from their left side. For straight movements the pedestrians were equally likely to be struck beginning from the left or right side of the street. After adjustment for pedestrian's age, vehicle movement was a significant predictor of severe injuries (p < 0.0001) and case fatality (p = 0.003). The association between vehicle precrash movement and severe injuries (p = 0.551) and case fatality (p = 0.912) vanished after adjusting for impact speed. This indicated that the observed association was probably the result of the difference in impact speed and not the precrash movement of the vehicle. CONCLUSION: Pedestrian safety interventions that aim at environmental modifications, such as crosswalk repositioning, might be the most efficient means in reducing right- or left-turn collisions at intersection, while pedestrians' behavioral modifications should be the priority for alleviating the magnitude of the collisions that happen in vehicles' straight movements.

An evaluation of the association between vehicle type and the source and severity of pedestrian injuries.

To evaluate the effect of vehicle type (passenger vehicle vs. light truck vehicle) on crash trajectory and on the consequent source and severity of pedestrian injury, we analyzed data from the Pedestrian Crash Data Study (PCDS), conducted by National Highway Traffic Safety Administration (NHTSA) from 1994 to 1998. While 62% of the adults in PV (passenger vehicle)-related crashes were carried by the vehicle, such pedestrian-vehicle interaction was observed only in 28% of LTV (light truck vehicle)-adult crashes. Being thrown forward or knocked down were the most common (65%) type of pedestrian-vehicle interactions for LTV-adult crashes. For children, 93% of those struck by LTVs and 46% of those struck by PVs were thrown forward or knocked down. For adults, LTVs were more likely than PVs to cause thorax (37% vs. 20%) and abdomen injuries (33% vs. 18%). For children, LTVs were more likely than PVs to cause injuries to the upper extremity (71% vs. 56%) and abdomen (14% vs. 8%). For adults struck by PVs the most common sources of injury were windshield for head injuries (63%), hood surface for thorax (67%), abdomen (58%), spine (30%), and upper extremity (36%) injuries, and bumper for the lower extremity injuries (60%). The leading causes of injury for adult-LTV crashes were ground for head (39%) and upper extremity (37%) injuries, hood edge for thorax (48%) and abdomen (56%) injuries, hood surface for spine injuries (36%), and bumper for lower extremity injuries (45%). For child-PV crashes, ground was the most common source of face (37%) abdomen (83%), spine (43%), and upper extremity injuries (54%). For children hit by LTVs, 52% of face, 67% of abdomen, 100% of spine, and 60% of upper extremity injuries were attributed to ground contacts. Altogether, the major sources of injury were hood surface and windshield for PV-pedestrian crashes and hood surface and hood edge for LTV-pedestrian crashes. Changes in design, such as altering the geometry and stiffness of front-end structures, might be associated with considerable decrease in the frequency and severity of pedestrian injury.

Sex and age distribution in transport-related injuries in Tehran.

Intercountry or regional differences in patterns of injury by the road user type have significant implication for prevention policies. In order to have an estimate from the existing conditions of transport-related injuries (TRIs) and especially to evaluate sex and age distribution of traffic accident victims, we analyzed information of 8426 hospitalized trauma patients during 13 months of data gathering process. Forty-five percent of the injuries were related to car accidents and men/women ratio in these patients was 4.2/1. The highest men/women ratio was (16/1) for motorcyclists, while the lowest ratio (1/1), was for rear seat car passengers. Mean (+/-S.D.) age of the patients was 31 (+/-18), and men were nearly 2 years younger than women (33 versus 31). Sixty-seven percent of the females' and 44% of the males' injuries were related to pedestrian crashes. Motorcycle-related injuries in men and car passenger related injuries in women were the second most common type of crash (42 and 22%, respectively). The use of protective devices in our population was worrisome. In only 6% of the male motorcyclists helmet use was reported, and 3% of the male car occupants had used seatbelts at the time of the accident. The condition in the female population was much worse and no use of the protective devices was reported in this group of the patients. Crude mortality rate in men was nearly two times that of women (6.2% versus 3.8%). After adjustment for age, injury severity score (ISS) and category of the road users, men and women had similar mortality rate.