Driver obesity and the risk of fatal injury during traffic collisions

A radiographic and physical analysis of factors affecting seat belt position in sitting car seat

The characteristic subcutaneous hemorrhage along the seat belt in motor vehicle accidents is called the seat belt sign (SBS). The risk of organ injuries is especially high when abdominal SBS is located above the anterior superior iliac spine (ASIS). The purpose of this study analyzed the physical and radiographic factors of healthy volunteers sit on car seat that affect initial position of abdominal seat belt, namely "lap belt", related to the seat belt injury. This study was examined prospectively relation between physical characteristics of one hundred healthy volunteers and lap belt position sitting the car seat. Physical findings were clarified age, sex, height, body mass index (BMI), and waist circumference. Radiographical findings were measured lumber lordosis (LL), sacral slope (SS), and initial lap belt position by marking with lead tape for the center and ASIS of the lap belt installed on the driver's car seat. In the lateral X-ray image, we measured the horizontal distance (X-value) and vertical distance (Z-value) from the ASIS to the central marker. The lap belt angle was determined to measure the angle between the horizontal line and the straight line connecting the upper edges of the markers. Statistical analysis of the relationships between physical characteristics and radiological findings was performed. X-value and Z-value were positively correlated with body weight, BMI, and waist circumference, while the lap belt angle was negatively correlated with body weight, BMI, and waist circumference. The relationship between physical characteristics and the initial position of seat belt was analyzed. Since the lap belt is positioned higher than the ASIS in occupants with a high BMI, it is likely to cause seat belt injury. This analysis can help to develop safer seat belts and to enlighten car occupants.

Exploring Factors That Influence Injured Patients’ Outcomes following Road Traffic Crashes: A Multi-Site Feasibility Study

Background: Injuries arising from Road Traffic Crashes (RTCs) are a major health problem in Saudi Arabia (SA). The purpose of the study was to determine the feasibility of conducting a multi-center research study to explore factors that influence the mortality of RTC-related trauma patients in SA. Methods: A multi-center observational study was undertaken involving both prospective and retrospective data collected from three hospitals. In-hospital patient mortality thirty days post-crash was the primary outcome variable. The feasibility of the study methods including the quality of data were evaluated and pilot results pertaining to factors predicting mortality were examined. Results: The overall mortality rate (n = 572 RTC victims) was (7.5%). A logistic regression model identified four independent predictors of mortality following an RTC: treatment at a non-trauma center-based hospital, SBP ≤ 90 mmHg, GCS ≤ 8, and ISS ≥ 20. With respect to the assessment of the study method’s feasibility, missing data was problematic, especially for variables pertaining to crash characteristics and prehospital care. Conclusions: Collecting multi-center injury data in SA has logistic challenges, predominantly associated with the comparability and completeness of data sets as well as the need for manual screening and data collection at some institutions. Despite these limitations, this study has demonstrated the feasibility of a method that could be utilized in further large nationwide studies to understand and examine the factors that influence injured patients’ outcomes following RTCs.

The Association of Body Mass Index and Outcomes in Adult Patients with Chest Wall Injuries

BACKGROUND

Thoracic injury secondary to rib fractures following motor vehicle collisions (MVCs) significantly contribute to morbidity and mortality. While obesity has reached epidemic proportions, little is known regarding how BMI impacts outcomes in MVCs. The aim of this study was to examine how BMI impacts outcomes in MVC patients with rib fractures.

METHODS

The ACS-TQIP Database was utilized to evaluate adult MVC patients with ≥3 rib fractures. Patients with a non-thoracic AIS ≥3 were excluded, to focus on chest injuries. Patients were sorted according to the presence or absence of flail chest injuries and BMI into groups with a low (<15), intermediate (15-24), or severe (≥25) ISS.

RESULTS

Overweight and obese patients in the non-flail cohort had decreased odds of pneumothorax in all ISS groups (P < 0.05). Overweight (P = 0.049) and obese (P = 0.011) patients in the low ISS non-flail cohort had decreased odds of splenic laceration. In the non-flail cohort, obese patients with a low and intermediate ISS had decreased odds of pulmonary contusion (P < 0.01). Obese patients in the low and intermediate ISS non-flail cohorts had increased odds of PE (P < 0.05). In both the flail and non-flail cohorts, obese patients with an intermediate ISS had decreased odds of liver laceration (P < 0.05), as well as a longer HLOS, ICU-LOS, and mechanical ventilation time (P < 0.01).

CONCLUSION

Obesity affects associated injuries, complications, and hospital outcomes in a complex way after MVC related chest wall trauma. Thus, the effect of BMI should be taken into consideration when assessing and treating obese MVC trauma patients.

Assessing the Cushion Effect: A Systematic Review and Meta-Analysis of the Role of Obesity in Motor Vehicle Injuries and Fatalities

PURPOSE

A systematic review and meta-analysis were done to evaluate the effect of obesity in injury and mortality due to motor vehicle accidents.

MATERIALS & METHODS

The systematic review consisted of 20 studies meeting the inclusion criteria. The meta-analysis was conducted on these studies to analyze obesity as a risk factor for specific injuries, as well as overall injury and mortality compared to non-obese patients.

RESULTS

The data revealed that obesity was associated with increased lower extremity injuries (odds ratio [OR] = 1.44, 95% confidence interval [CI] = 1.19-1.69, P ≤ 0.05), neck injuries (OR = 3.38, 95% CI = 1.58-5.19, P ≤ 0.05), and overall mortality (OR = 1.51, 95% CI = 1.40-1.61, P ≤ 0.05). When stratified for obesity class with class I as BMI >30.1-34.9, class II BMI 35-39.9, and class III BMI >40, only class II (OR = 1.20, 95% CI = 1.15-1.24, P ≤ 0.05) and class III (OR = 1.49, 95% CI = 1.30-1.68, P ≤ 0.05) were associated with increased mortality risk. No significant differences were seen with head, upper extremity, thoracic, abdominal, or pelvic injuries.

CONCLUSION

Obesity is a risk factor in motor vehicle accidents for fatality and injury, specifically lower extremity and neck injuries.

A state-of-the-art review of factors that predict mortality among traumatic injury patients following a road traffic crash

BACKGROUND

Traffic related injuries are a major public health problem worldwide with millions of people dying every year. The objective of this state-of-the-art review was to identify the factors reported in the literature as being associated with mortality for trauma patients following road traffic crashes.

METHOD

A systematic search was undertaken of PubMed/MEDLINE, EMBASE, CINAHL, Web of Science, and Cochrane Library databases to identify articles published in the past two decades (2000-2020). Of 8257 records, 4507 remained for title, abstract and full text screening after duplicates were removed. The level of evidence of selected studies was assessed using The National Health and Medical Research Council (NHMRC) guideline.

RESULTS

This review included eighty primary research studies examining mortality risk factors following a road traffic crash. The study identified factors in five categories; (i) demographic factors; (ii) behavioural factors; (iii) crash characteristics; (iv) environmental and timing factors; (v) injury severity and pre-injury/condition. The primary studies are summarised in a matrix. Included studies included level II to level IV levels of evidence based on the NHMRC criteria.

CONCLUSION

This study shows that there are a large number of factors associated with increased risk of mortality following diverse types of traffic crashes. Understanding these wide-ranging factors can strengthen injury and mortality prevention by guiding decision makers about where to focus strategy implementation.

A Method to Use Kriging With Large Sets of Control Points to Morph Finite Element Models of the Human Body

As developing finite element (FE) human body models for automotive impact is a time-consuming process, morphing using interpolation methods such as kriging has often been used to rapidly generate models of different shapes and sizes. Kriging can be computationally expensive when many control points (CPs) are used, i.e., for very detailed target geometry (e.g., shape of bones and skin). It can also lead to element quality issues (up to inverted elements) preventing the use of the morphed models for finite element simulation. This paper presents a workflow combining iterative subsampling and spatial subdivision methodology that effectively reduces the computational costs and allows for the generation of usable models through kriging with hundreds of thousands of control points. As subdivision introduces discontinuities in the interpolation function that can cause distortion of elements on the boundaries of individual subdivision areas, algorithms for smoothing the interpolation over those boundaries are proposed and compared. Those techniques and their combinations were tested and evaluated in a scenario of mass change on the detailed 50th percentile male model of the global human body models consortium (GHBMC): the model, which has body mass index (BMI) 25.34, was morphed toward a statistical surface model of a person with body mass index 20, 22.7 and 35. 234 777 control points were used to successfully morph the model in less than 15 min on an office PC. Open source implementation is provided.

The relationship between weight indices and injuries and mortalities caused by the motor vehicle accidents: a systematic review and meta-analysis

BACKGROUND

The relationship between weight indices and injuries and mortality in motor vehicle accidents is unknown. Systematic review studies addressing the collection and analysis of the relationship in investigations are very limited. The purpose of this systematic review is to determine the relationship between BMI, obesity and overweight with mortality and injuries and their severity and vulnerable organs after the motor vehicle accident.

METHODS

The databases (MEDLINE/PUBMED, EMBASE, Web of Science, etc) were searched for relevant abstracts using certain keywords. Of all the articles, similar ones were removed considering different filters. The collected data were entered into the STATA SE v 13.1. The heterogeneity of the data was analyzed using i2 statistics. In addition, the estimates of the study were done based on the age group (children and adults) and the impact of obesity on different regions of the body.

RESULTS

A direct relationship was observed between the overall BMI and the degrees of injuries (CI=0.503-1.139), and mortality due to motor vehicle accident (CI=1.267-1.471). A positive relationship was found between obesity and AIS+2 (CI=0.653-1.426), and AIS+3 (CI=1.184-1.741), and ISS (CI=1.086-1.589). Also, a negative relationship between overweight and injuries rates, and a direct relationship between overweight and mortality (CI=0.979-1.167), and injuries with index of AIS+2 (CI=1.178-0.768) and AIS+3 (CI=0.48-2.186) were found.

CONCLUSIONS

The prediction of injury, mortality and severity of injuries in the motor vehicle accident by the variable of obesity and overweight determines the need to design prevention programs for this vulnerable group at all levels.

Age modifies the association between driver's body mass index and death following motor vehicle crashes

OBJECTIVE

We explored the association between body mass index (BMI) and the odds of a driver being fatally injured in a motor vehicle crash (MVC) after controlling for driver, crash, and vehicle factors known to independently contribute to injury severity. We hypothesized that BMI would be related to risk of fatal injury after controlling for other risk factors but that BMI would also interact with age.

METHOD

We analyzed crashes involving 2 passenger type vehicles (1998-2015) from the Fatality Analysis Reporting System using binary logistic regression (with generalized estimating equations) to compute odds ratios and 95% confidence intervals of fatality by BMI status.

RESULTS

Our results indicate that BMI status confers varying levels of risk at different ages. For example, a very low BMI of 18 increased the odds of fatality (relative to BMI = 21.75) more at age 85 (adjusted odds ratio [aOR] = 1.17, 95% confidence interval [CI], 1.09, 1.26) than at age 25 (aOR = 1.03, 95% CI, 1.01, 1.06). Similarly, a very high BMI of 42.5 increased the odds of fatality (relative to BMI = 21.75) more at age 85 (aOR = 2.17, 95% CI, 1.64, 2.87) than at age 25 (aOR = 1.33, 95% CI, 1.21, 1.45). Conversely, a moderate BMI of 27.5 was protective for drivers aged 85 (aOR = 0.94, 95% CI, 0.88, 0.99) but had no effect for drivers aged 25 (aOR = 1.00, 95% CI, 0.98, 1.02). We also found that a higher BMI was associated with higher odds of wearing a seat belt improperly or not wearing one at all.

CONCLUSION

The relationship between BMI and fatality risk needs to be considered by policymakers, public health officials, and vehicle manufacturers to ensure that vehicles are safe for all occupants regardless of their weight, size, or shape.

Heat waves and fatal traffic crashes in the continental United States

BACKGROUND

A better understanding of how heat waves affect fatal traffic crashes will be useful to promote awareness of drivers' vulnerability during an extreme heat event.

OBJECTIVE AND METHODS

We applied a time-stratified case-crossover design to examine associations between heat waves and fatal traffic crashes during May-September of 2001-2011 in the continental United States (US). Heat waves, defined as the daily mean temperature >95% threshold for ≥2 consecutive days, were derived using gridded 12.5 km² air temperatures from Phase 2 of the North American Land Data Assimilation System (NLDAS-2). Dates and locations of fatal traffic crash records were acquired from the National Highway Traffic Safety Administration (NHTSA).

RESULTS

Results show a significant positive association between fatal traffic crashes and heat waves with a 3.4% (95% CI: 0.9, 5.9%) increase in fatal traffic crashes on heat wave days versus non-heat wave days. The association was more positive for 56-65 years old drivers [8.2% (0.3, 16.7%)] and driving on rural roadways [6.1% (2.8, 9.6%)]. Moreover, a positive association was only present when the heat wave days were characterized by no precipitation [10.9% (7.3%, 14.6%)] and medium or high solar radiation [24.6% (19.9%, 29.5%) and 19.9% (15.6%, 24.4%), respectively].

CONCLUSIONS

These findings are relevant for developing targeted interventions for these driver groups and driving situations to efficiently reduce the negative effects of heat waves on fatal traffic crashes.

Prevalence of work-site injuries and relationship between obesity and injury among U.S. workers: NHIS 2004-2012

INTRODUCTION

Studies have reported associations between obesity and injury in a single occupation or industry. Our study estimated the prevalence of work-site injuries and investigated the association between obesity and work-site injury in a nationally representative sample of U.S. workers.

METHODS

Self-reported weight, height, and injuries within the previous three months were collected annually for U.S. workers in the National Health Interview Survey (NHIS) from 2004-2012. Participants were categorized as normal weight (BMI: 18.5-24.9kg/m(2)), overweight (BMI: 25.0-29.9), obese I (BMI: 30.0-34.9), and obese II (BMI: 35+). The prevalence of injury and prevalence ratios from fitted logistic regression models was used to assess relationships between obesity and injury after adjusting for covariates. Sampling weights were incorporated using SUDAAN software.

RESULTS

During the 9-year study period from 2004 to 2012, 1120 workers (78 workers per 10,000) experienced a work-related injury during the previous three months. The anatomical sites with the highest prevalence of injury were the back (14.3/10,000±1.2), fingers (11.5±1.3), and knees (7.1±0.8). The most common types of injuries were sprains/strains/twists (41.5% of all injuries), cuts (20.0%), and fractures (11.8%). Compared to normal weight workers, overweight and obese workers were more likely to experience work-site injuries [overweight: PR=1.25 (95% CI=1.04-1.52); obese I: 1.41 (1.14-1.74); obese II: 1.68 (1.32-2.14)]. These injuries were more likely to affect the lower extremities [overweight: PR=1.48, (95% CI=1.03-2.13); obese I: 1.70 (1.13-2.55); obese II: 2.91 (1.91-4.41)] and were more likely to be due to sprains/strains/twists [overweight: PR=1.73 (95% CI=1.29-2.31); obese I: PR=2.24 (1.64-3.06); obese II: PR=2.95 (2.04-4.26)].

CONCLUSIONS

Among NHIS participants, overweight and obese workers were 25% to 68% more likely to experience injuries than normal weight workers.

PRACTICAL APPLICATIONS

Weight reduction policies and management programs may be effectively targeted towards overweight and obese groups to prevent or reduce work-site injuries.

Driver's obesity and road crash risks in the United States

OBJECTIVE

We assessed obesity trends in U.S. drivers involved in fatal crashes since 1999 and distinguished whether crash risk factors were different between obese and nonobese drivers.

METHODS

We included only drivers of passenger cars involved in fatal traffic crashes between January 1, 1999, and December 31, 2012. Obesity was classified according to the World Health Organization guidelines and profiled between 1999 and 2012 using the adjusted prevalence ratio (aPR) from log-binomial regression models. Differences in crash risks (e.g., driver's fatality, drunk driving, seat belt nonuse) between obese and nonobese drivers were estimated as adjusted odds ratios (aORs) using logistic regression models.

RESULTS

A total of 753,024 U.S. drivers were involved in fatal crashes, for which obesity information was available for 534,887. About 56% (n = 299,078) were driving passenger cars. The prevalence of class I obesity increased from 10% in 1999 to 14% in 2012 (aPR = 1.50, 95% confidence interval [CI], 1.42-1.58), class II obesity from 3 to 5% (aPR = 2.22, 95% CI, 2.05-3.01), and class III obesity from 1 to 2% (aPR = 2.65; 95% CI, 2.27-3.10). Compared to nonobese controls, obese drivers had significantly higher risks for fatality (1.10 ≤ aOR ≤ 1.47), seat belt nonuse (1.00 ≤ aOR ≤ 1.21), need for extrication (1.01 ≤ aOR ≤ 1.23), and ambulance transport time ≥30 min (1.01 ≤ aOR ≤ 1.28). Compared to nonobese controls, obese drivers were less likely to drink drive (0.41 ≤ aOR ≤ 0.72) or speed >65 mph (0.78 ≤ aOR ≤ 0.93).

CONCLUSION

The rising national prevalence of obesity extends to U.S. drivers involved in fatal crashes and indicates the need to improve seat belt use, vehicle design, and postcrash care for this vulnerable population.

Prevalence of Injury in Occupation and Industry: Role of Obesity in the National Health Interview Survey 2004 to 2013

OBJECTIVES

The aim of this study was to estimate prevalence of injury by occupation and industry and obesity's role.

METHODS

Self-reported injuries were collected annually for US workers during 2004 to 2013. Prevalence ratios (PRs) and 95% confidence intervals (CIs) were obtained from fitted logistic regression models.

RESULTS

Overall weighted injury prevalence during the previous three months was 77 per 10,000 workers. Age-adjusted injury prevalence was greatest for Construction and Extraction workers (169.7/10,000) followed by Production (160.6) among occupations, while workers in the Construction industry sector (147.9) had the highest injury prevalence followed by the Agriculture/Forestry/Fishing/Mining/Utilities sector (122.1). Overweight and obese workers were 26% to 45% more likely to experience injuries than normal-weight workers.

CONCLUSION

The prevalence of injury, highest for Construction workers, gradually increased as body mass index levels increased in most occupational and industry groups.

Obesity and trauma mortality: Sizing up the risks in motor vehicle crashes

BACKGROUND

Protective effects of safety devices in obese motorists in motor vehicle collisions (MVC) remain unclear. Aim of our study is to assess the association between morbid obesity and mortality in MVC, and to determine the efficacy of protective devices. We hypothesised that patients with morbid obesity will be at greater risk of death after MVC.

METHODS

A retrospective analysis of MVC patients (age ≥16 y.o.) was performed using the National Trauma Data Bank from 2007 to 2010. Patients with recorded comorbidity of morbid obesity (BMI≥40) were identified. Patients dead on arrival, with isolated traumatic brain injury, or incomplete data were excluded. The primary outcome was in-hospital mortality. Multivariate logistic regression was performed.

RESULTS

Our sample of 214,306 MVC occupants included 10,260 (4.8%) morbidly obese patients. Mortality risk was greatest among occupants with morbid obesity (OR_crude 1.74 [1.54-1.98]). After adjusting for patient demographics, safety device and physiological severity, odds of death was 1.52 [1.33-1.74] times greater in motorists with morbid obesity. Motorists with morbid obesity were at greater risk of death if no restraint (OR 1.84 [1.47-2.31]), seatbelt only (OR 1.48 [1.17-1.86]), or both seatbelt and airbag were present (OR 1.49 [1.13-1.97]). No significant differences in the odds of death exist between drivers with morbid obesity and non-morbidly obese drivers with only airbag deployment (OR 0.99 [0.65-1.51]).

CONCLUSIONS

Motorists with morbid obesity are at greater risk of MVC. Regardless of safety device use, occupants with morbid obesity remained at greater risk of death. Further research examining the effectiveness of vehicle restraints in drivers with morbid obesity is warranted.

Body mass index and the risk of injury in adults: a cross-sectional study

OBJECTIVES

To investigate the association between body mass index (BMI) and the risk of nonfatal body injury.

METHODS

We analyzed data from 113,203 adults who participated in the Canadian Community Health Survey conducted in 2009-2010. Log-binomial models were used to estimate crude and adjusted relative risks of the association between BMI and the risk of body injury for men and women.

RESULTS

Of 113,203 adult participants, 15,194 had self-reported body injuries during the past 12 months, with a 12-month cumulative incidence of 13.7% (weighted to Canadian population). There was a significant interaction between gender and BMI in relation to the risk of body injury, and therefore, analyses were stratified by gender. For women, we found a significant association between BMI and an increased risk of body injury. Women with an increased BMI had a significant increased risk of body injuries as compared with those with normal weight (adjusted relative risk: 1.13, 95% confidence interval (CI)=1.02-1.25 for BMI 30.0-34.9 kg m(-)(2); 1.17, 95% CI=1.00-1.37 for BMI 35.0-39.9 kg m(-)(2); 1.41, 95% CI=1.16-1.69 for BMI ⩾ 40 kg m(-)(2)). A reduced risk of injury was observed in underweight women. There was no significant association between BMI and the risk of body injury for men. Obese persons of both gender were more likely to suffer injuries to the knee and lower leg, and in less demanding activities such as household chores or using the stairs.

CONCLUSIONS

We therefore conclude that increased BMI may be a risk factor for body injury in women, but not in men.