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: 18.5–24.9 kg/m²), 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.     

Venting of deflagrations: hydrocarbon–air and hydrogen–air systems

A set of 34 experiments on vented hydrocarbon–air and hydrogen–air deflagrations in unobstructed enclosures of volume up to 4000 m³ was processed with use of the advanced lumped parameter approach. Reasonable compliance between calculated pressure–time curves and experimental pressure traces is demonstrated for different explosion conditions, including high, moderate, low and extremely low reduced overpressures in enclosures of different shape (L_max:L_min up to 6:1) with different type and position of the ignition source relative to the vent, for near-stoichiometric air mixtures of acetone, methane, natural gas and propane, as well as for lean and stoichiometric hydrogen–air mixtures. New data were obtained on flame stretch for vented deflagrations.The fundamental Le Chatelier–Brown principle analog for vented deflagrations has been considered in detail and its universality has been confirmed. The importance of this principle for explosion safety engineering has been emphasized and proved by examples.A correlation for prediction of the deflagration–outflow interaction number, χ/μ, on enclosure scale, Bradley number and vent release pressure is suggested for unobstructed enclosures and a wide range of explosion conditions. Fractal theory has been employed to verify the universality of the dependence revealed of the deflagration–outflow interaction number on enclosure scale.In spite of differences between the thermodynamic and kinetic parameters of hydrocarbon–air and hydrogen–air systems, they both obey the same general regularities for vented deflagrations, including the Le Chatelier–Brown principle analog and the correlation for deflagration–outflow interaction number.     

Occupational injury and psychological distress among U.S. workers: The National Health Interview Survey, 2004–2016

Introduction: Injuries at work may negatively influence mental health due to lost or reduced working hours and financial burden of treatment. Our objective was to investigate, in U.S. workers (a) the prevalence of serious psychological distress (SPD) by injury status (occupational, non-occupational, and no injury) and injury characteristics, and (b) the association between injury status and SPD. Methods: Self-reported injuries within the previous three months were collected annually for 225,331 U.S. workers in the National Health Interview Survey (2004–2016). Psychological distress during the past 30 days was assessed using the Kessler 6 (K6) questions with Likert-type scale (0–4, total score range: 0–24). SPD was defined as K6 ≥ 13. Prevalence ratios (PR) from fitted logistic regression models were used to assess relationships between injury and SPD after controlling for covariates. Results: The prevalence of SPD was 4.74%, 3.58%, and 1.56% in workers reporting occupational injury (OI), non-occupational injury (NOI), and no injury, respectively. Workers with head and neck injury had the highest prevalence of SPD (Prevalence: OI = 7.71%, NOI = 6.17%), followed by workers with scrape/bruise/burn/bite (6.32% for those with OI). Workers reporting OI were two times more likely to have SPD compared to those without injury (PR = 2.19, 95%CI: 1.62–2.96). However, there was no significant difference in SPD between workers with OI and workers with NOI (PR = 0.98, 95%CI: 0.65–1.48). Conclusion: The prevalence of SPD varied by injury status with the highest being among workers reporting OI. We found that the workers reporting OI were significantly more likely to have SPD than those without injury, but not more than those with NOI. Practical Applications: Mental health management programs by employers are necessary for workers who are injured in the workplace.     

The role of drug and alcohol use and the risk of motor vehicle crashes in Shiraz,Iran, 2014: A case–crossover study

Background: Traffic accidents and traffic-related injuries and mortality have become a major public health concern in Iran. This study aimed to examine the role of drug and alcohol use in motor vehicle accidents in Iran.

Methods: This case–crossover study was conducted on 441 drivers who survived a road traffic crash and were taken to the emergency department of Shahid Rajaee trauma hospital in Shiraz, southern Iran. Data were collected using checklists that included demographic characteristics and drug and alcohol use prior to driving. Alcohol and drug use was identified through self-report, and cannabis, morphine, and methamphetamine urine tests were used to confirm drug abuse among drivers.

Results: In total 17.9% of drivers reported using drugs (cannabis, opium, or metamphetamine) and 8.84% of drivers reported consuming alcohol prior to the collision. The crude odds ratios (ORs) for having a crash for opium, cannabis, and metamphetamine were 1.94 (95% interval confidence [CI], 1.11–3.38), 2.37 (95% CI, 1.03–5.42), 5.5 (95% CI, 1.21–24.81), respectively, and for all drugs was 3.83 (95% CI, 2.28–6.43). The OR for alcohol was 3.5 (95% CI, 1.73–7.06) based on self-report.

Conclusion: Drug and alcohol use are increasing the risk of traffic crashes in Iran. Risk-reducing programs must be designed and implemented.     

Conflict,justice, and inequality: Why perceptions of leader–member exchange differentiation hurt performance in teams

To better understand why leader–member exchange (LMX) differentiation in teams may be detrimental to individual and team performance, we propose that team members' perception of LMX differentiation (PLMXD) is more important than statistical measures of LMX differentiation. Specifically, we hypothesize a multilevel model in which relationship conflict and procedural justice (climate) mediate the relationships of individual and collective PLMXDs with individual and team performance, respectively. Using a sample of 235 individuals in 53 teams, we found that individual PLMXD was negatively related to individual performance through relationship conflict perceptions, controlling for LMX. At the team level, collective PLMXD was negatively related to team performance through procedural justice climate and relationship conflict, controlling for a statistical measure of LMXD. Theoretical implications and directions for future research are explored.     

Characterization of drug and alcohol use among senior drivers fatally injured in U.S. motor vehicle collisions, 2008–2012

Objective: Adults 65 years of age and older comprise the fastest growing demographic in the United States. As substance use is projected to increase in this population, there is concern that more seniors will drive under the influence of impairing drugs. The purpose of this analysis was to characterize the drug and alcohol usage among senior drivers fatally injured (FI) in traffic collisions.

Methods: Data from the Fatality Analysis Reporting System were analyzed from 2008 to 2012. Commonly used classes and specific drugs were explored. Rates of drug use, multiple drugs, concomitant drug and alcohol use, and alcohol use alone were generated using Poisson regression with robust error variance estimation. Rates were compared to a reference population of FI middle-aged drivers (30 to 50 years old) using rate ratios.

Results: Drug use among FI senior drivers occurred in 20.0% of those tested. Among drug-positive FI senior drivers, narcotics and depressants were frequent. The prevalence of testing positive for any drug, multiple drugs, combined drug and alcohol, and alcohol use alone among FI seniors were 47% less (relative risk [RR] = 0.53, 95% confidence interval [CI], 0.47, 0.62), 59% less (RR = 0.41, 95% CI, 0.34, 0.51), 87% less (RR = 0.13, 95% CI, 0.09, 0.19), and 77% less (RR = 0.23, 95% CI, 0.19, 0.28), respectively, compared to FI middle-aged drivers.

Conclusions: Though overall drug use is less common among FI senior drivers relative to FI middle-aged drivers, driving under the influence of drugs may be a relevant traffic safety concern in a portion of this population.     

Traumatic brain injury mortality among U.S. children and adolescents ages 0–19 years, 1999–2017

IntroductionTo examine recent traumatic brain injury (TBI) mortality changes among Americans aged 0–19 years by sex, age, urbanicity, state, and intent/causes of injury. Method: TBI mortality per 100,000 population and average annual percent changes (AAPCs), plus 95% confidence intervals (CIs) based on Joinpoint regression models. Results: Age-adjusted TBI mortality among Americans aged 0–19 years declined consistently, though at varying rates between 1999 and 2013 (AAPC = −4.8%, 95%CI: −6.3%, −3.2%), and then significantly increased from 4.42 per 100,000 population in 2013 to 5.17 per 100,000 population in 2017 (AAPC = 3.4%, 95% CI: 1.7%, 5.1%). During the study time period, boys, rural children, and youth aged 15–19 years had higher TBI mortality rates than girls, urban children, and younger children, respectively. TBI mortality from unintentional transport crashes decreased substantially in all age groups between 1999 and 2017, and especially from 1999 to 2010. TBI mortality from suicide increased significantly from 2008 to 2017 in the 10–14-year age group (AAPC = 14.6%, 95% CI: 12.6%, 16.6%) and from 2007 to 2017 in the 15–19-year age group (AAPC = 6.3%, 95% CI: 3.8%, 8.7%). Unintentional transport crashes were the leading cause of TBI-related mortality in 46 states in 1999, but by 2017, suicide became the first leading cause in 14 states. Conclusions: Pediatric TBI mortality declined consistently between 1999 and 2013 and increased significantly from 2013 to 2017, driven primarily by the mortality decrease from unintentional transport crashes and increase in suicide mortality. The spectrum of leading causes of pediatric TBI mortality changed across age groups and over time from 1999 to 2017. Practical Applications: TBI mortality increases in the United States since 2013 are driven primarily by increasing suicide rates, a trend that merits the attention of policy-makers and injury researchers. Action should be taken to curb growing TBI mortality rates among adolescents aged 10–19 years.