Investigating traffic fatality trends and restraint use among rear-seat passengers in the United States, 2000–2016

Introduction: Motor-vehicle crash is one of the leading causes of unintentional injury death in the United States. Previous studies focused on fatalities among drivers and front-seat passengers, with a limited number of studies examining rear-seat passenger fatalities. The objectives of this study were to assess trends in rear-seat passenger motor-vehicle fatalities in the United States from 2000 to 2016 and to identify demographic factors associated with being unrestrained among fatally injured rear-seat passengers. Methods: Rear-seat passenger fatality data were obtained from the Fatality Analysis Reporting System (FARS) database. The fatality rate ratios for overall rear-seat passengers and for different age and sex groups were determined by comparing fatality rates in 2000 and 2016 using random effects models. Risk ratios of being unrestrained for age and sex groups were obtained using general estimating equations. Results: Compared to 2000, the overall rear-seat passenger fatality rate in 2016 decreased by 44% (95% confidence interval [CI]: 39–49%). In particular, the fatality rate among rear-seat passengers decreased more in males than females, and passengers aged 14–19 years experienced a larger decline than all other age groups. Fatally injured male rear-seat passengers had a higher risk of being unrestrained (adjusted risk ratio: 1.06, 95% CI: 1.04–1.07) than their female counterparts, and both youngest (≤13 years) and oldest (65–85 years) passengers were less likely to be unrestrained than those aged 20–64 years. Conclusions: Overall, fatality rates among rear-seat passengers have declined, with differential degrees of improvement by age and sex. Practical Applications: Continued restraint use enforcement campaigns targeted at teenagers and males would further preserve them from fatal injuries and improve traffic safety for the overall population.     

Crash rates over time among younger and older drivers in the SHRP 2 naturalistic driving study

Objective: To examine crash rates over time among 16–17-year-old drivers compared to older drivers. Methods: Data were from a random sample of 854 of the 3,500 study participants in SHRP 2, a U.S. national, naturalistic driving (instrumented vehicle) study. Crashes/10,000 miles by driver age group, 3-month period, and sex were examined within generalized linear mixed models. Results: Analyses of individual differences between age cohorts indicated higher incidence rates in the 16–17-year old cohort relative to older age groups each of the first four quarters (except the first quarter compared to 18–20 year old drivers) with incident rate ratios (IRR) ranging from 1.98 to 18.90, and for the full study period compared with drivers 18–20 (IRR = 1.69, CI = 1.00, 2.86), 21 to 25 (IRR = 2.27, CI = 1.31, 3.91), and 35 to 55 (IRR = 4.00, CI = 2.28, 7.03). Within the 16–17-year old cohort no differences were found in rates among males and females and the decline in rates over the 24-month study period was not significant. Conclusions: The prolonged period of elevated crash rates suggests the need to enhance novice young driver prevention approaches such as Graduated Driver’s Licensing limits, parent restrictions, and post-licensure supervision and monitoring. Practical Applications: Increases are needed in Graduated Driver’s Licensing limits, parent restrictions, and postlicensure supervision and monitoring.     

Prevalence and demographic differences in microaccidents and safety behaviors among young workers in Canada

IntroductionThe present study examines the self-reported frequency of non-lost work time workplace injuries (“microaccidents”) and the frequency of three types of work-related safety behaviors (i.e., safety voice, safety compliance, and safety neglect) recalled over a four-week period.MethodWe analyzed data on microaccidents and safety behaviors from 19,547 young workers (aged 15–25 years, Mdn = 18 years; 55% male) from multiple Canadian provinces.ResultsApproximately one-third of all young workers recalled experiencing at least one microaccident at work in the last four weeks. Comparisons across three age groups revealed that younger workers, particularly between the ages of 15–18, reported more frequent microaccidents, less safety voice, less safety compliance, and more safety neglect than workers aged 19–22. This pattern of results also held for comparisons between workers in 19–22 and 23–25 age groups, except for safety voice which did not differ between these two older age groups. In terms of gender, males and females reported the same frequency of microaccidents, but males reported more safety voice, more safety compliance, and more safety neglect than females did. The results and limitations of the present study are discussed.ConclusionFrequency of microaccidents and safety behavior vary among young worker age sub-groups.     

Unintentional injury deaths in children and youth, 2010–2019

Background: Unintentional injuries are the leading cause of death for children and youth aged 1–19 in the United States. The purpose of this report is to describe how unintentional injury death rates among children and youth aged 0–19 years have changed during 2010–2019. Method: CDC analyzed 2010–2019 data from the National Vital Statistics System (NVSS) to determine two-year average annual number and rate of unintentional injury deaths for children and youth aged 0–19 years by sex, age group, race/ethnicity, mechanism, county urbanization level, and state. Results: From 2010–2011 to 2018–2019, unintentional injury death rates decreased 11% overall—representing over 1,100 fewer annual deaths. However, rates increased among some groups—including an increase in deaths due to suffocation among infants (20%) and increases in motor-vehicle traffic deaths among Black children (9%) and poisoning deaths among Black (37%) and Hispanic (50%) children. In 2018–2019, rates were higher for males than females (11.3 vs. 6.6 per 100,000 population), children aged < 1 and 15–19 years (31.9 and 16.8 per 100,000) than other age groups, among American Indian or Alaska Native (AIAN) and Blacks than Whites (19.4 and 12.4 vs. 9.0 per 100,000), motor-vehicle traffic (MVT) than other causes of injury (4.0 per 100,000), and rates increased as rurality increased (6.8 most urban [large central metro] vs. 17.8 most rural [non-core/non-metro] per 100,000). From 2010–2011 to 2018–2019, 49 states plus DC had stable or decreasing unintentional injury death rates; death rates increased only in California (8%)—driven by poisoning deaths. Conclusion and Practical Application: While the overall injury death rates improved, certain subgroups and their caregivers can benefit from focused prevention strategies, including infants and Black, Hispanic, and AIAN children. Focusing effective strategies to reduce suffocation, MVT, and poisoning deaths among those at disproportionate risk could further reduce unintentional injury deaths among children and youth in the next decade.     

An Analysis of Young Driver Crash Types and the Associated Lifetime Care Cost in Victoria,Australia

Objective: The elevated crash involvement rate of young drivers is well documented. Given the higher crash risk of young drivers and the need for innovative policy and programs, it remains important to fully understand the type of crashes young drivers are involved in, and knowledge of the lifetime care cost of crashes can support effective policy development. The aim of this article is to document the number and type of young driver crashes, as well as the associated lifetime care cost over a 9-year period (2005–2013) in Victoria, Australia.

Methods: In Victoria, Australia, the Transport Accident Commission (TAC) has legislated responsibility for road safety and the care of persons injured in road crashes, irrespective of fault. TAC claims data for the period 2005–2013 were used to document the number and type of young driver crashes. Lifetime care costs (past and future payment liabilities) were calculated by Taylor Fry actuarial consultancy. License and population data were used to define the crash involvement rate of young drivers.

Results: Over the 9-year period, 16,817 claims were lodged to the TAC by drivers 18–25 years of age following a crash. There were 646 fewer drivers aged 18–25 killed and injured in 2013, compared to 2005, representing an unadjusted change of ?28.7% (?29.8% males; ?28.4% females). The total lifetime care cost of young drivers killed and injured in Victoria for the period 2005–2013 was estimated to be AU$634 million (US$493 million). Differences between males and females, single- and multivehicle crashes, and fatalities and injuries were found to be statistically significant. Run-off-road crashes and crashes from opposing direction were overrepresented in the lifetime care costs for young driver claimants. Twenty-eight injured drivers were classified as high-severity claims. These 28 claimants require additional long-term care, which was estimated to be AU$219 million; of these 28, 24 were male (85.7%). The long-term care costs for these 28 drivers (0.16%) accounts for 34.5% of the total lifetime care cost of all 18- to 25-year-old injured drivers.

Conclusions: By using no-fault lifetime care costs that account for medical and like expenses, rehabilitation, and social reintegration costs, a more accurate understanding of the cost of young driver crashes can be determined. Application of these costs to specific crash types highlights new priorities and opportunities for developing programs to reduce young driver crashes.     

First year as a licensed car driver: Gender differences in crash experience

Objective: To explore the crash experience and crash consequences of newly licensed male and female drivers aged 18–29 years.Methodology: A national register-based population cohort of persons born between 1970 and 1972 was followed for the period 1988–2000 on the basis of crash data in Swedish police records. The analyses focused on two crash categories regardless of consequences: single car (SC) and car-to-motor vehicle (CMV).Results: Crash incidence for men was nearly double that of women in all age groups in both crash categories. Age had a protective effect for both sexes, especially for SC crashes. Males, but not females, showed a lag in time from driving license issue date to first crash for SC crashes, which increased with age of obtaining a license. Men’s crash fatality rate was five times higher than that of women for SC crashes (32.2 and 6.1 per 1000, respectively), but the rate was comparable for CMV crashes (16.1 and 15.7, respectively). The crash morbidity rate was 25–30% higher for male drivers in both crash categories.Conclusions: Both young age and male sex emerge as important determinants of crash risk and crash consequences among young Swedish drivers.     

Gender aspects of work-related injuries in a Swedish municipality

The purpose of this study was to investigate gender aspects of work-related injuries in a Swedish municipality (population 41,000). All unintentional injuries treated at in- and out-patient facilities were recorded during a period of 1 year. The work-related injuries were mapped out in more detail with the help of standardized and structured surveys via telephone interviews and hospital records. The rate of work-related injuries among the gainfully employed was 33 per 1000. Males were observed to suffer more work-related injuries than females (46 compared to 12 per 1000 gainfully employed persons), and there were gender differences with regard to work-related injuries and injury event patterns. Young men showed the highest rate of injuries. Injuries caused during machine operation were the most common for both males and females, amounting to almost one quarter of all injuries. Injuries caused by falls were most common amongst females in the age groups 15–24 (25%) and 45–64 (28%). More attention should be given to gender aspects of work-related injuries and their prevention.     

Crash risk by driver age,gender, and time of day using a new exposure methodology

Introduction: Concerns have been raised that the nonlinear relation between crashes and travel exposure invalidates the conventional use of crash rates to control for exposure. A new metric of exposure that bears a linear association to crashes was used as basis for calculating unbiased crash risks. This study compared the two methods – conventional crash rates and new adjusted crash risk – for assessing the effect of driver age, gender, and time of day on the risk of crash involvement and crash fatality. Method: We used police reports of single-car and multi-car crashes with fatal and nonfatal driver injuries that occurred during 2002–2012 in Great Britain. Results: Conventional crash rates were highest in the youngest age group and declined steeply until age 60–69 years. The adjusted crash risk instead peaked at age 21–29 years and reduced gradually with age. The risk of nighttime driving, especially among teenage drivers, was much smaller when based on adjusted crash risks. Finally, the adjusted fatality risk incurred by elderly drivers remained constant across time of day, suggesting that their risk of sustaining a fatal injury due to a crash is more attributable to excess fragility than to crash seriousness. Conclusions: Our findings demonstrate a biasing effect of low travel exposure on conventional crash rates. This implies that conventional methods do not yield meaningful comparisons of crash risk between driver groups and driving conditions of varying exposure to risk. The excess crash rates typically associated with teenage and elderly drivers as well as nighttime driving are attributed in part to overestimation of risk at low travel exposure. Practical Applications: Greater attention should be directed toward crash involvement among drivers in their 20s and 30s as well as younger drivers. Countermeasures should focus on the role of physical vulnerability in fatality risk of elderly drivers.     

Responsibility of drivers, by age and gender, for motor-vehicle crash deaths

Problem: Motor-vehicle crash rate comparisons by age and gender usually are based on the extent to which drivers in a particular age/gender category are themselves injured or involved in crashes (e.g., the number of 20-year-old females in crashes). Basing comparisons instead on the extent to which drivers in various age/gender groups are responsible for deaths (including themselves) in their crashes is more revealing of their overall contribution to the problem. Methods: Data from the Fatality Analysis Reporting System (FARS, 1996–2000) were used in the analysis, which was based on crashes that involved one or two vehicles only. Drivers in fatal single-vehicle crashes were assumed to have responsibility for the crash. In fatal two-vehicle crashes, driver operator errors reported by police were used to assign crash responsibility. Results: When all crashes were considered, both the youngest and oldest drivers were most likely to be responsible for deaths in their crashes. In two-vehicle crashes, the oldest drivers were more likely than young drivers to be responsible. Young males were more likely than young females to be responsible for crash deaths, whereas females in their 50s and older were more likely than same-age males to be responsible. In terms of responsibility for deaths per licensed driver, young drivers, especially males, had the highest rates because of their high involvement rates and high responsibility rates. The majority of deaths for which young drivers were responsible occurred to people other than themselves, especially passengers in their vehicles, whereas the bulk of the deaths for which older drivers were responsible were their own. Discussion: The results highlight the contribution of young drivers to the motor-vehicle crash problem, the need for measures such as passenger restrictions in graduated licensing systems, and the need for vehicle modifications to better protect older occupants.     

Near crash characteristics among risky drivers using the SHRP2 naturalistic driving study

Problem: Previous research have focused extensively on crashes, however near crashes provide additional data on driver errors leading to critical events as well as evasive maneuvers employed to avoid crashes. The Strategic Highway Research Program 2 (SHRP2) Naturalistic Driving Study contains extensive data on real world driving and offers a reliable methodology to study near crashes. The current study utilized the SHRP2 database to compare the rate and characteristics associated with near crashes among risky drivers. Methods: A subset from the SHRP2 database consisting of 4,818 near crashes for teen (16–19 yrs), young adult (20–24 yrs), adult (35–54 yrs), and older (70+ yrs) drivers was used. Near crashes were classified into seven incident types: rear-end, road departure, intersection, head-on, side-swipe, pedestrian/cyclist, and animal. Near crash rates, incident type, secondary tasks, and evasive maneuvers were compared across age groups. For rear-end near crashes, near crash severity, max deceleration, and time-to-collision at braking were compared across age. Results: Near crash rates significantly decreased with increasing age (p < 0.05). Young drivers exhibited greater rear-end (p < 0.05) and road departure (p < 0.05) near crashes compared to adult and older drivers. Intersection near crashes were the most common incident type among older drivers. Evasive maneuver type did not significantly vary across age groups. Near crashes exhibited a longer time-to-collision at braking (p < 0.01) compared to crashes. Summary: These data demonstrate increased total near crash rates among young drivers relative to adult and older drivers. Prevalence of specific near crash types also differed across age groups. Timely execution of evasive maneuvers was a distinguishing factor between crashes or near crashes. Practical Applications: These data can be used to develop more targeted driver training programs and help OEMs optimize ADAS to address the most common errors exhibited by risky drivers.     

The use and risk of portable electronic devices while cycling among different age groups

Introduction: In the Netherlands, a survey was set up to monitor the extent of the use of portable, electronic devices while cycling amongst different age groups of cyclists and to estimate the possible consequences for safety. Method: The main research questions concerned age differences in the self-reported use of electronic devices while cycling, self-reported crash involvement and risk, and self-reported compensatory behaviour. Teen cyclists (12–17 years) and young adult cyclists (18–34 years) were more frequent users, and also more indiscriminate users of portable devices while cycling than middle-aged and older adult cyclists (35–49 years; 50 + years). Results: After statistical correction for influences on crash risk of urbanization level, weekly time spent cycling, and cycling in more demanding traffic situations, the odds of being involved in a bicycle crash were estimated to be higher for teen cyclists and young adult cyclists who used electronic devices on every trip compared to same age groups cyclists who never used these devices. For middle-aged and older adult cyclists, the use of portable electronic devices was not a significant predictor of bicycle crashes, but frequency of cycling in demanding traffic situations was. Possible implications for education or legal measures are discussed. Impact on Industry: Results may inform researchers, policy makers, and cyclists themselves. Educational campaigns may use risk information to warn young cyclists about risk of device use while cycling.     

Factors associated with concussion symptom knowledge and attitudes towards concussion care-seeking among parents of children aged 5–10 years

Background: Understanding parents’ concussion-related knowledge and attitudes will contribute to the development of strategies that aim to improve concussion prevention and sport safety for elementary school children. This study investigated the association between parent- and child-related factors and concussion symptom knowledge and care-seeking attitudes among parents of elementary school children (aged 5–10 years). Methods: Four hundred parents of elementary school children completed an online questionnaire capturing parental and child characteristics; concussion symptom knowledge (25 items, range = 0–50; higher = better knowledge); and concussion care-seeking attitudes (five 7-point scale items, range = 5–35; higher = more positive attitudes). Multivariable ordinal logistic regression models identified predictors of higher score levels. Adjusted odds ratios (aOR) with 95% confidence intervals (CI) excluding 1.00 were deemed statistically significant. Results: Select parent and child characteristics were associated with higher score levels for both outcomes. For example, odds of better knowledge level in parents were higher with increased age (10-year increase aOR = 1.59; 95% CI = 1.10–2.28), among females (aOR = 3.90; 95% CI = 2.27–6.70), and among white/non-Hispanics (aOR = 1.79; 95%CI = 1.07–2.99). Odds of more positive concussion care-seeking attitude levels were higher among parents with a college degree (aOR = 1.98; 95%CI = 1.09–3.60). Child sports participation was not associated with higher score levels for either outcome. Conclusions: Certain elementary school parent characteristics were associated with parents’ concussion symptom knowledge and care-seeking attitudes. While the findings suggest providing parents with culturally and demographically relevant concussion education might be helpful, they also emphasize the importance of ensuring education/prevention regardless of their children’s sports participation. Practical Applications: Pediatric healthcare providers and elementary schools offer an optimal community-centered location to reach parents with this information within various communities.     

Driver licensing,motor-vehicle crashes,and moving violations among older adults

IntroductionDriving is important for well-being among older adults, but age-related conditions are associated with driving reduction or cessation and increased crash risk for older drivers. Our objectives were to describe population-based rates of older drivers’ licensing and per-driver rates of crashes and moving violations.Methods: We examined individual-level statewide driver licensing, crash, and traffic citation data among all New Jersey drivers aged ≥ 65 and a 35- to 54-year-old comparison group during 2010–2014. Rate ratios (RR) of crashes and moving violations were estimated using Poisson regression.Results: Overall, 86% of males and 71% of females aged ≥ 65 held a valid driver’s license. Older drivers had 27% lower per-driver crash rates than middle-aged drivers (RR: 0.73, 95% CI: 0.73, 0.74)—with appreciable differences by sex—but 40% higher fatal crash rates (RR: 1.40 [1.24, 1.58]). Moving violation rates among older drivers were 72% lower than middle-aged drivers (RR: 0.28 [0.28, 0.28]).Conclusion: The majority of older adults are licensed, with substantial variation by age and sex. Older drivers have higher rates of fatal crashes but lower rates of moving violations compared with middle-aged drivers.Practical applications: Future research is needed to understand the extent to which older adults drive and to identify opportunities to further reduce risk of crashes and resultant injuries among older adults.     

Seasonal variation in fall-related emergency department visits by location of fall – United States, 2015

Introduction: In the United States, fall-related emergency department (ED) visits among older adults (age 65 and older) have increased over the past decade. Studies document seasonal variation in fall injuries in other countries, while research in the United States is inconclusive. The objectives of this study were to examine seasonal variation in older adult fall-related ED visits and explore if seasonal variation differs by the location of the fall (indoors vs. outdoors), age group, and sex of the faller. Methods: Fall-related ED visit data from the National Electronic Injury Surveillance System-All Injury Program were analyzed by season of the ED visit, location of the fall, and demographics for adults aged 65 years and older. Results: Total fall-related ED visits were higher during winter compared with other seasons. This seasonal variation was found only for falls occurring outdoors. Among outdoor falls, the variation was found among males and adults aged 65 to 74 years. The percentages of visits for weather-related outdoor falls were also higher among males and the 65–74 year age group. Conclusions: In 2015, there was a seasonal variation in fall-related ED visits in the United States. Weather-related slips and trips in winter may partially account for the seasonal variation. Practical Implications: These results can inform healthcare providers about the importance of screening all older adults for fall risk and help to identify specific patients at increased risk during winter. They may encourage community-based organizations serving older adults to increase fall prevention messaging during winter.     

Age group differences in collision risk

Introduction

The purpose of the current study was to examine differences in factors associated with self-reported collision involvement of three age groups of drivers based on a large representative sample of Ontario adults. Method: This study was based on data from the CAMH Monitor, an ongoing cross-sectional telephone survey of Ontario adults 18 years and older from 2002 to 2005. Three age groups were examined: 18-34 (n = 1,294), 35-54 (n = 2,428), and 55+ (n = 1,576). For each age group sample, a logistic regression analysis was conducted of self-reported collision involvement in the last 12 months by risk factor measures of driving exposure (kilometers driven in a typical week, driving is stressful, and driving on busy roads), consuming five or more drinks of alcohol on one occasion (past 12 months), cannabis use (lifetime, and past 12 months), and driving after drinking among drinkers (past 12 months), controlling for demographics (gender, region, income, and marital status). Results: The study identified differences in factors associated with self-reported collision involvement of the three age groups of adult drivers. The logistic regression model for the youngest group revealed that drivers who reported that driving was stressful at least some of the time, drank five or more drinks on an occasion, and drove after drinking had an increased risk of collision involvement. For the middle age group, those who reported using cannabis in the last 12 months had significantly increased odds of reporting collision involvement. None of the risk factor measures showed significant associations with collision risk for older drivers (aged 55+). Impact: The results suggest potential areas for intervention and new directions for future research.     

Injuries associated with the use of riding mowers in the United States, 2002-2007

Context: To examine injuries among patients treated in an emergency department (ED) related to the use of a riding lawn mower.Design and Setting: Data were obtained from the National Electronic Injury Surveillance System for the years 2002-2007. National estimates of ED visits for injuries associated with the use of a riding lawn mower were analyzed. Narrative text entries were categorized to provide a detailed record of the circumstances precipitating the injury. Average annual rates were calculated and logistic regression analyses were employed to determine risk estimates for patient disposition and demographic characteristics related to ED visits for injuries associated with riding mowers.Results: From 2002 through 2007, there were an estimated 66,341 ED visits for injuries related to the use of riding lawnmowers in the U.S., with an average annual rate of 6.0 ED visits per 100,000 males, and 1.6 ED visits per 100,000 females. Older adults had higher rates of ED visits for injuries (7.2/100,000) than younger age groups. The most common injuries involved contusions (24%); sprains/strains (22%) and fractures (17%). The majority of patients (90%) were treated and released the same day. Results of logistic regression analyses revealed that older adults were more likely to be hospitalized when compared to younger age groups; and incidents involving rollovers [OR = 5.45 (95% CI = 3.22-9.23)] and being run over [6.01 (95% CI 3.23-11.17)] were more likely to result in hospitalization when compared to all other circumstances of injury.Conclusions: Riding mowers present injury patterns and circumstances that are different than those reported for push mowers. Circumstances related to injuries and age groups affected were varied, making prevention of riding mower injuries challenging. Application/Impact: Findings support the need to increase awareness and/or change the design of riding mowers with respect to risk of rollover injuries.     

Boating-related drowning in Australia: Epidemiology,risk factors and the regulatory environment

Objective: Recreational boating is a popular pastime in many high income countries, and is a leading activity prior to drowning. This study reports on unintentional fatal drowning associated with boating-related incidents in Australia. Methods: A total population, retrospective, cross sectional design examined all boating-related unintentional drowning deaths between July 1, 2005 and June 30, 2015. Variables examined included age, sex, location of drowning incident, vessel type, activity, presence of alcohol/drugs, and lifejacket wear. Relative risk (with a 95% confidence interval) was calculated using fatal drowning rates per 100,000 population and rates per 100,000 registered vessels. Chi square analysis and non-parametric tests for significance were applied. Statistical significance was deemed p < .05. Results: A total of 415 people drowned while boating during the study period, 91.8% male and 35.7% aged between 25 and 44 years. Men were 10 times more likely to drown when boating than females (RR = 10.64 CI:7.55–14.97). Over one-quarter (28.7%) of incidents involved alcohol, in 30.6% drugs were identified (31.3% were illegal) and 90.4% were not wearing a lifejacket. Children were more at risk of drowning on a houseboat than adults (RR = 7.13; CI:1.61–31.61). Females were more likely to drown than males when using a personal watercraft (RR = 10.53; CI:2.75–40.33). Conclusion: Boaters may be taking unnecessary risks by disregarding safety regulations, such as not wearing lifejackets and substance use (such as alcohol and illegal drugs). Boating in remote locations presents a high risk of drowning. While safety regulations are in place, enforcement and behavior change remain challenges. Practical application: Findings support recommendations for increased enforcement of alcohol-related regulations and introducing drug-testing for boaters. Consistency of boating safety regulations, especially around lifejacket wear, is recommended to influence behavior change. The effectiveness of current lifejacket regulations need to be critically evaluated in the context of increasing wear rates for adults and children.     

Injuries among electric power industry workers, 1995–2013

IntroductionWorkers in the electric power industry face many risks of injury due to the high diversity of work tasks performed in potentially hazardous and unpredictable work environments.MethodWe calculated injury rates by age, sex, occupational group, and injury type among workers in the Electric Power Research Institute’s (EPRI) Occupational Health and Safety Database (OHSD), which contains recordable injury, medical claims, and personnel data from 18 participating electric power companies from 1995 to 2013.ResultsThe OHSD includes a total of 63,193 injuries over 1,977,436 employee-years of follow-up, for an overall injury rate of 3.20 injuries per 100 employee-years. Annual injury rates steadily decreased from 1995 to 2000, increased sharply in 2001, and subsequently decreased to their lowest rate of 1.31 injuries per 100 employee-years in 2013. Occupations with the highest injury rates were welders (13.56 per 100 employee-years, 95% CI 12.74–14.37), meter readers (12.04 per 100 employee-years, 95% CI 11.77–12.31), and line workers (10.37 per 100 employee-years, 95% CI 10.19–10.56). Males had an overall higher injury rate compared to females (2.74 vs. 1.61 per 100 employee-years) although some occupations, such as meter reader, had higher injury rates for females. For all workers, injury rates were highest for those in the 21 to 30 age group (3.70 per 100 employee-years) and decreased with age. Welders and machinists did not follow this trend and had higher injury rates in the 65 + age group. There were 63 fatalities over the 1995 to 2013 period, with 21 fatalities (33.3%) occurring among line workers.ConclusionsAlthough injury rates have decreased over time, certain high-risk groups remain (i.e., line workers, mechanics, young males, older welders and machinists, and female meter readers).Practical applicationsProtective measures and targeted safety programs may be warranted to ensure the safety of electric power workers.     

Lower Leg Injury Reference Values and Risk Curves from Survival Analysis for Male and Female Dummies: Meta-analysis of Postmortem Human Subject Tests

Objective: Derive lower leg injury risk functions using survival analysis and determine injury reference values (IRV) applicable to human mid-size male and small-size female anthropometries by conducting a meta-analysis of experimental data from different studies under axial impact loading to the foot–ankle–leg complex.

Methods: Specimen-specific dynamic peak force, age, total body mass, and injury data were obtained from tests conducted by applying the external load to the dorsal surface of the foot of postmortem human subject (PMHS) foot–ankle–leg preparations. Calcaneus and/or tibia injuries, alone or in combination and with/without involvement of adjacent articular complexes, were included in the injury group. Injury and noninjury tests were included. Maximum axial loads recorded by a load cell attached to the proximal end of the preparation were used. Data were analyzed by treating force as the primary variable. Age was considered as the covariate. Data were censored based on the number of tests conducted on each specimen and whether it remained intact or sustained injury; that is, right, left, and interval censoring. The best fits from different distributions were based on the Akaike information criterion; mean and plus and minus 95% confidence intervals were obtained; and normalized confidence interval sizes (quality indices) were determined at 5, 10, 25, and 50% risk levels. The normalization was based on the mean curve. Using human-equivalent age as 45 years, data were normalized and risk curves were developed for the 50th and 5th percentile human size of the dummies.

Results: Out of the available 114 tests (76 fracture and 38 no injury) from 5 groups of experiments, survival analysis was carried out using 3 groups consisting of 62 tests (35 fracture and 27 no injury). Peak forces associated with 4 specific risk levels at 25, 45, and 65 years of age are given along with probability curves (mean and plus and minus 95% confidence intervals) for PMHS and normalized data applicable to male and female dummies. Quality indices increased (less tightness-of-fit) with decreasing age and risk level for all age groups and these data are given for all chosen risk levels.

Conclusions: These PMHS-based probability distributions at different ages using information from different groups of researchers constituting the largest body of data can be used as human tolerances to lower leg injury from axial loading. Decreasing quality indices (increasing index value) at lower probabilities suggest the need for additional tests. The anthropometry-specific mid-size male and small-size female mean human risk curves along with plus and minus 95% confidence intervals from survival analysis and associated IRV data can be used as a first step in studies aimed at advancing occupant safety in automotive and other environments.     

Real-world adjustments of driver seat and head restraint in Saab 9-3 vehicles

Objective: Whiplash-associated disorder (WAD), commonly denoted whiplash injury, is a worldwide problem. These injuries occur at relatively low changes of velocity (typically <25 km/h) in impacts from all directions. Rear impacts, however, are the most common in the injury statistics. Females have a 1.5–3 times higher risk of whiplash injury than males.

?Improved seat design is the prevailing means of increasing the protection of whiplash injury for occupants in rear impacts. Since 1997, more advanced whiplash protection systems have been introduced on the market, the Saab Active Head Restraint (SAHR) being one of the most prominent. The SAHR—which is height adjustable—is mounted to a pressure plate in the seatback by means of a spring-resisted link mechanism.

?Nevertheless, studies have shown that seats equipped with reactive head restraints (such as the SAHR) have a very high injury-reducing effect for males (～60–70%) but very low or no reduction effect for females. One influencing factor could be the position of the head restraint relative to the head, because a number of studies have reported that adjustable head restraints often are incorrectly positioned by drivers.

?The aim was to investigate how female and male Saab drivers adjust the seat in the car they drive the most.

Methods: The seated positions of drivers in stationary conditions have been investigated in a total of 76 volunteers (34 females, 42 males) who participated in the study. Inclusion criteria incorporated driving a Saab 9–3 on a regularly basis.

Results: The majority of the volunteers (89%) adjusted the head restraint to any of the 3 uppermost positions and as many as 59% in the top position.

?The average vertical distance between the top of the head and the top of the head restraint (offset) increase linearly with increasing statures, from an average of ?26 mm (head below the head restraint) for small females to an average of 82 mm (head above the head restraint) for large males. On average, the offset was 23 mm for females, which is within a satisfactory range and in accordance with recommendations; the corresponding value for males was 72 mm.

?The backset tended to be shorter among female volunteers (on average 27 mm) compared to the male volunteers (on average 44 mm). Moreover, the backset tended to increase with increasing statures.

Conclusions: Incorrect adjustment of the head restraint cannot explain the large differences found between the sexes in the effectiveness of the SAHR system.