Assault Deterrents and Educators' Risk of Physical Assault: A Case-Control Study.

The study purpose was to identify associations between assault deterrent presence in kindergarten through 12th (K-12) grade schools and physical assaults (PAs) against educators. Data collected through a two-phase study identified physical and nonphysical violent events and utilized a nested case-control study to identify PA risk/protective factors. Analyses included multivariable modeling. Adjusted analyses demonstrated a significant decreased risk of PA with routine locker searches (odds ratio [OR] = 0.49, 95% confidence interval [CI] [0.29, 0.82]). Also important, although not statistically significant, were presence of video monitors (OR = 0.72, 95% CI [0.50, 1.03]), intercoms (OR = 0.77, 95% CI [0.55, 1.06]), and required school uniforms/dress codes (OR = 0.74, 95% CI [0.52, 1.07]). These findings are integral to school nursing practice in which there is opportunity to influence application of relevant pilot intervention efforts as a first step in determining the potential efficacy of broad-based interventions that can positively impact the problem of school-related violence.

Evaluation of the efficacy of an intersection conflict warning system at two-way stop-controlled rural intersections: difference-in-differences and triple-difference analytical approaches.

OBJECTIVE: Intersection conflict warning systems (ICWSs) have been implemented at high-risk two-way stop-controlled intersections to prevent right-angle crashes and associated injuries. This study involved investigation of the impacts of ICWSs on crash reductions. METHODS: The study used a quasi-experimental design to analyse the potential causal relations between Minnesota's ICWSs and various crash rate outcomes (including total, injury, non-injury, targeted right-angle and non-right-angle crashes) in pre-post analyses. A restricted randomisation method enabled identification of three controls to each ICWS treatment intersection, and included as many comparable intersection characteristics as possible. Annual crash rates (per year per intersection) were analysed over the same periods before and after system activation for treatment and control intersections in each matched group. Pre-crash data for 3 years and post-crash data for up to 5 years were included, ranging from 2010 to 2018. Negative binomial regression models with generalised estimating equations were applied to estimate the average, immediate and continuing treatment effects of ICWSs, through the difference-in-differences and difference-in-difference-in-difference approaches, respectively. RESULTS: The ICWS treatment was significantly associated with a decreasing trend for targeted right-angle crash rates posttreatment. Although not statistically significant, most crash rate outcomes appeared to be elevated immediately after treatment (statistically significant for sideswipe crashes only). Pre-post differences in average crash rates (over entire periods), except for incapacitating injury-related crashes, were not statistically significant between treatment and control intersections. CONCLUSIONS: The study provided important insight into potential causal associations between intersection safety countermeasures and crashes at high-risk rural two-way stop-controlled intersections.

Design and evaluation of a rural intersection conflict warning system and alternative designs among various driver age groups.

Advanced Rural Intersection Conflict Warning Systems (RICWS) were deployed as countermeasures to reduce severe right-angle crashes at rural thru-STOP controlled intersections across the United States (U.S.). The simulator study designed and evaluated alternative RICWS designs to existing RICWS interventions, in varying rural driving scenarios, across age groups (N = 40 novice teenage, 40 middle-aged, and 40 older drivers). Each participant was randomly assigned to a RICWS design, either the original or an alternative, and drove through sequences of 17 thru-STOP controlled rural intersections (nine RICWS intervention and eight control intersections). Drivers' gap acceptance performance, intersection driving performance, traffic violation behaviors and self-reported workload were evaluated between intervention and control intersections. Regression models, applying the Generalized Estimating Equation (GEE), enabled efficacy determination of each RICWS design and an aggregated RICWS intervention effect, averaged across all simulated RICWS designs, among different levels of moderating factors. The safety performance and possible risks associated with the use of different RICWS designs were identified. Specifically, the original RICWS design had a significantly greater risk of STOP-sign violations at clear-view intersections with low traffic volumes, compared with control intersections (Risk Ratio = 2.18, 95% CI = 1.03 to 4.64). Except for Alternative RICWS Design 1, the alternative RICWS designs did not appear to outperform the Original RICWS Design. The moderating effects of drivers' ages and intersection types on aggregated RICWS intervention effects were also examined. This study provides important safety implications for development and evaluation of intelligent intersection warning systems, targeted to vulnerable driver populations at high-risk rural intersections.

Janitor ergonomics and injuries in the safe workload ergonomic exposure project (SWEEP) study.

INTRODUCTION: A Minnesota union identified to researchers at the University of Minnesota a concern relevant to a possible relation between their daily workload and outcome of occupational injuries among a population of janitors. OBJECTIVE: To assess if the ergonomic workload is related to injuries among janitors. METHODS: Following an initial group discussion among janitors, which identified common and hazardous tasks potentially leading to occupational injuries, a questionnaire was developed, pre-tested, and distributed to the janitors. Questions addressed various exposures, including workload, and comprehensive information regarding injury occurrence over two six-month sequential periods (May 2016-October 2016, November 2016-April 2017). Quantitative ergonomic analyses were performed on a sub-group of janitors (n = 30); these included data collection to identify Borg Perceived Exertion (Borg) and Rapid Entire Body Assessment (REBA) scores. Descriptive, multivariable with bias adjustment analyses were conducted on the resulting data. RESULTS: Eight tasks were found to be common for janitors. All average REBA scores for the tasks were identified in the high-risk category. The task of repeatedly emptying small trash cans (<25lb) was significantly related to injuries. Average Borg scores fell between the very light perceived exertion and somewhat difficult perceived exertion categories. Multivariable regression analyses indicated that age-sex-standardized ergonomic workload, measured by task frequencies and REBA or Borg scores, was positively related to injury occurrence. CONCLUSIONS: Standardized ergonomic workload was positively related to injury occurrence. This information serves as a basis for further research and potential intervention efforts.

A longitudinal study of work-related psychosocial factors and injuries: Implications for the aging United States workforce.

INTRODUCTION: This study aimed to identify psychosocial work factors that may individually or, in combination, influence injury outcomes among aging United States (U.S.) workers. METHODS: Data from the U.S. Health and Retirement Study (HRS) of 3305 working adults, aged 50 years and above, were used to identify associations between work-related psychosocial factors and injury incidence from 2006 to 2014, using adjusted incidence rate ratios. RESULTS: Employees perceiving their work as high in psychological and physical demands/efforts, low in support, and rewards, compared to those in workplaces with low demands, high support, and high rewards, had a risk of injury two times greater. Males, compared with females, had a greater risk for injuries when interactions among several psychosocial work-related factors were modeled. CONCLUSIONS: The fact that important gender-based differences emerged when interactions among the psychosocial factors and injury were modeled, suggests opportunities for further research and potential interventions to enhance the working environment.

Janitor workload and occupational injuries.

BACKGROUND: This study was designed to identify potential effects of workload and sleep on injury occurrence. METHODS: Questionnaires were disseminated to janitors in the SEIU Local 26 union; 390 responded and provided information on workload, sleep, and injury outcomes. Quantitative measurements of workload and sleep were collected via FitBit devices from a subset of 58 janitors. Regression techniques were implemented to determine risk. RESULTS: Thirty-seven percent reported increased workload over the study period Adjusted analyses indicated a significant effect of change in workload (RR: 1.94; 95%CI: 1.40-2.70) and sleep hours (RR: 2.21; 95%CI: 1.33-3.66) on occupational injury. Among those with sleep disturbances, injury risk was greater for those with less than five, versus more than five, days of moderate to vigorous physical activity; RR: 2.77; 95%CI: 1.16-6.59). CONCLUSIONS: Increased workload and sleep disturbances increased the risk of injury, suggesting employers should address these factors to mitigate occupational injuries.

Occupational Injury Among Janitors: Injury Incidence, Severity, and Associated Risk Factors.

OBJECTIVE: Determine injury incidence and severity and potential associated risk factors for injury, among janitors. METHODS: Questionnaires were disseminated to 1200 full-time janitors in the Service Employees International Union (SEIU) Local 26 union; 390 responded and provided information on their injury experiences and exposures, based on personal characteristics and work-related activities. Multivariable analyses, including bias adjustment, were implemented using directed acyclic graphs to determine potential risk. RESULTS: Among the janitors, 34% reported experiencing at least one injury; 16% of cases resulted in hospital admittance. Significantly increased risks were identified for age, ethnicity, shift start time, and physician-diagnosed depression. CONCLUSIONS: Knowledge of specific risk and protective factors is valuable, and can serve as a basis for further in-depth studies and inform the development of targeted intervention strategies aimed to reduce occurrence of these injuries.

A longitudinal study of work-related injuries: comparisons of health and work-related consequences between injured and uninjured aging United States adults.

BACKGROUND: Age may affect one's susceptibility to the myriad physical hazards that may pose risks for work-related injuries. Aging workers are not only at risk for work-related injuries but, also, at even higher risk for more severe health and work-related consequences. However, limited longitudinal research efforts have focused on such injuries among the aging workforce. This study aimed to investigate the association between physical work-related factors and injuries among United States (U.S.) workers, and then compare the injured and uninjured workers with regard to consequences including, functional limitations, and reduced working hours post injury. A cohort of 7212 U.S. workers aged 50 years and above from the U.S. Health and Retirement Study were retrospectively followed from 2004 to 2014. Data on exposures were lagged by one survey wave prior to the outcome of work-related injuries and consequences, respectively. Crude and adjusted incident rate ratios, and hazard ratios were estimated using generalized estimating equations and Cox models. RESULTS: Risk of experiencing a work-related injury event was over two times greater among those whose job had work requirements for physical effort, lifting heavy loads, and stooping/kneeling/crouching, compared to those who did not. Over time, injured compared to uninjured workers had higher risks of functional limitations and working reduced hours. CONCLUSIONS: The aging workforce is at a high risk of experiencing injuries. Further, injured adults were not only more likely to incur a disability prohibiting daily life-related activities, over time, but, also, were more likely to work reduced hours. It will be important to consider accommodations to minimize functional limitations that may impair resulting productivity.

Risk factors for unintentional occupational injury among urban transit bus drivers: a cohort longitudinal study.

PURPOSE: Although many studies have focused on bus operators' occupational diseases, work-related injury and associated risk factor data are limited. The purpose of this longitudinal study was to investigate unintentional injury and exposures that may affect injury risk among metropolitan bus operators. METHODS: Demographic, work-related, and injury data obtained from a metropolitan transit company for a 5-year period, enabled estimates of rates per 100 full time equivalents (FTEs) and adjusted Hazard Ratios (HRs), with 95% confidence intervals (CIs), using Generalized Estimating Equations and Cox proportional hazards models, respectively. RESULTS: The 2095 bus operators, included in this study, had an unintentional injury rate (95% CI) of 17.8 (16.1-19.7) per 100 FTEs. Multivariable analysis identified increased risks for operators who were female, compared to male (HR = 2.4; 2.0-2.8); worked less than 7 versus 7 to less than 12 hours per day (HR = 4.6; 3.8-5.5); and drove less than 7 versus 7 to less than 12 hours per day (HR = 3.2; 2.7-3.8). Suggestive increased risks were identified for operators working split versus straight shifts (HR = 1.2; 1.0-1.4) and for driving limited versus regular bus routes (HR = 1.36; 1.0-1.8). CONCLUSIONS: Results serve as a basis for further studies and inform the development of targeted intervention strategies to reduce bus operators' occupational injuries.

Workers' compensation loss prevention representative contact and risk of lost-time injury in construction policyholders.

INTRODUCTION: Insurance loss prevention (LP) representatives have access and contact with businesses and employees to provide targeted safety and health resources. Construction firms, especially those smaller in size, are a high-risk population. This research evaluated the association between LP rep contact and risk for lost-time injuries in construction policyholders. METHODS: Workers' compensation data were utilized to track LP rep contact with policyholders and incidence of lost-time injury over time. Survival analysis with repeated events modeling calculated hazard ratios (HR) and 95% confidence intervals (CI). RESULTS: Compared no LP contact, one contact was associated with a 27% reduction of risk (HR=0.73, CI=0.65-0.82), two with a 41% (HR=0.59, CI=0.51-0.68), and three or more contacts with a 28% reduction of risk (HR=0.72, CI=0.65-0.81). CONCLUSIONS: LP reps appear to be a valuable partner in efforts to reduce injury burden. Their presence or contact with policyholders is consistent with reduction in overall incidence of lost-time injuries. PRACTICAL APPLICATIONS: Reduction in lost-time injuries, resulting in reduced workers' compensation costs for policyholders and insurance companies, builds a business-case for safety and injury prevention. LP reps are often a low or no-cost benefit for insurance policyholders and may be an important injury prevention resource for small firms and/or those with lack of safety resources and staff.

Animal-related activities as risk factors for injuries among youth on agricultural operations.

Working with animals on agricultural operations is hazardous for youths. This study evaluated the associations between activities and injuries related to specific animal types. A case-control study within the Regional Rural Injury Study II included 425 youths (less than 20 years of age) with injuries related to their operation and 1,886 controls (randomly selected youths). Exposures of interest were collected for the months prior to injury events for cases and randomly selected months for controls, based on an injury incidence algorithm. Multivariate logistic regression characterized associations between specific animal-related activities and injury outcomes among youths who reported working with the same animals. Large proportions of cases and controls, respectively, worked with beef cattle (47%, 28%), followed by horses (28%, 14%), and dairy cattle (22%, 12%). Feeding was the primary activity associated with animals; over 80% of cases and controls were involved in this activity during relevant exposure months, followed by milking (63%, 44%) among those working with dairy cows and herding (81%, 61%) among beef cattle workers. Elevated risk of dairy cattle-related injury was associated with milking (odds ratio [OR]: 2.5; 95% confidence interval [CI]: 1.0-6.6) whereas beef cattle-related injuries were associated with calving (OR: 4.2; 95% CI: 2.1-8.6) and footwork (OR: 2.2; 95% CI: 1.0-4.9). Among youths working with animals, explicit activities can be identified that are associated with animal-specific injuries. The identification of relevant hazardous tasks is necessary for the development of effective prevention measures.

Evaluation of factors associated with work-related injuries to veterinary technicians certified in Minnesota.

OBJECTIVE: To evaluate the magnitude and consequences of work-related injuries and associated factors among veterinary technicians certified in Minnesota. DESIGN: Cross-sectional survey. SAMPLE: 1,427 certified veterinary technicians (CVTs). PROCEDURES: Surveys were used to collect data on demographics, personal characteristics, injury occurrences in the 12 months prior to survey completion, and injury consequences. Annual injury rates were estimated on the basis of demographic and work-related characteristics. Risk of injury associated with various factors was estimated by calculation of incidence rate ratios, controlling for multiple factors. RESULTS: 465 of 873 eligible CVTs reported 1,827 injury events (total and bite injury rates, 237 and 78 injuries/100 persons/y). Primary injury sources were cats and dogs, and most injuries occurred during animal restraint or treatment. Self-reported most severe injuries involved bites; cuts, lacerations, or scratches; bruises or contusions; and abrasions. Injury consequences included treatment and restricted work activity. Risk of work-related injury was lower for CVTs who worked < 40 h/wk than for those who worked ≥ 40 h/wk. The risk was higher for CVTs working in small animal or mixed mostly small animal facilities and lower for those working in mixed large and small animal facilities, commercial or industry operations, and government or regulatory facilities, compared with CVTs in colleges or universities. Handling 4 to > 6 (vs < 4) animal species during the 12 months prior to the survey and belief that injuries are not preventable were also associated with higher risk of injury. CONCLUSIONS AND CLINICAL RELEVANCE: Several factors associated with the risk of work-related injury among CVTs were identified. Beyond these risk factors, investigation of additional exposures is integral to relevant intervention strategies.

Evaluation of risk and protective factors for work-related bite injuries to veterinary technicians certified in Minnesota.

OBJECTIVE: To identify risk and protective factors for work-related bite injuries among veterinary technicians certified in Minnesota. DESIGN: Nested case-control study. SAMPLE: 868 certified veterinary technicians (CVTs). PROCEDURES: A questionnaire was mailed to CVTs who previously participated in a survey regarding work-related injuries and did (cases; 301 surveys sent) or did not (controls; 567) report qualifying work-related animal bite injuries in the preceding 12 months. Descriptive statistics were summarized. Demographic and work-related variables for the month preceding the bite injury (for cases) or a randomly selected month (controls) were assessed with univariate analysis (489 CVTs) and multivariate analysis of a subset of 337 CVTs who worked in small or mixed mostly small animal facilities. RESULTS: Responses were received from 176 case and 313 control CVTs. For the subset of 337 CVTs, risk of bite injury was higher for those < 25 years of age (OR, 3.82; 95% confidence interval [CI], 1.84 to 7.94) than for those ≥ 35 years of age, for those who had worked < 5 years (OR, 3.24; 95% CI, 1.63 to 6.45) versus ≥ 10 years in any veterinary facility, and for those who handled ≥ 5 species/d (OR, 1.99; 95% CI, 1.06 to 3.74) versus < 3 species/d. Risk was lower for CVTs who handled < 10 versus ≥ 20 animals/d (OR, 0.23; 95% CI, 0.08 to 0.71). CONCLUSIONS AND CLINICAL RELEVANCE: Several work-related factors were associated with the risk of work-related bite injury to CVTs. These findings may serve as a basis for development of intervention efforts and future research regarding work-related injuries among veterinary staff.

Case-control study of student-perpetrated physical violence against educators.

PURPOSE: Although prior research focused primarily on student-on-student school violence, educators are also at risk. This study was designed to identify risk factors for assaults against educators. METHODS: Kindergarten-grade 12 educators (n = 26,000), randomly selected from a state license database, were screened for eligibility (6,469, eligible) by mailed questionnaire. Phase 1 (12-month recall) identified eligible assault cases (n = 372) and controls (n = 1,116), June 2004 to December 2005; phase 2 (case-control study; response, 78%) enabled identification of exposures through 1-month recall before student-perpetrated assaults (cases) and randomly selected months (controls). Directed acyclic graphs enabled confounder selection for multivariable logistic regression analyses; reweighting adjusted for potential biases. RESULTS: Risks (odds ratios, 95% confidence intervals) increased for working in: Special Education (5.84; 4.07-8.39) and School Social Work (7.18; 2.72-18.91); kindergarten to second grade (1.81; 1.18-2.77); urban (1.95; 1.38-2.76) schools; schools with less than 50 (8.40; 3.12-22.63), 50-200 (3.67; 1.84-7.34), 201-500 (2.09; 1.32-3.29), and 501-1000 (1.94; 1.25-3.01) students versus more than 1000; schools with inadequate resources always/frequently (1.62; 1.05-2.48) versus infrequently/never; inadequate building safety always/frequently (4.48; 2.54-7.90) versus infrequently/never; and environments with physical barriers (1.50; 1.07-2.10). Risks decreased with routine locker searches (0.49; 0.29-0.85) and accessible exits (0.36; 0.17-0.74). CONCLUSIONS: Identification of assault risk factors provides a basis for further investigation and interventions.

Factors associated with civilian drivers involved in crashes with emergency vehicles.

Motor vehicle crashes involving civilian and emergency vehicles (EVs) have been a known problem that contributes to fatal and nonfatal injuries; however, characteristics associated with civilian drivers have not been examined adequately. This study used data from The National Highway Traffic Safety Administration's Fatality Analysis Reporting System and the National Automotive Sampling System General Estimates System to identify driver, roadway, environmental, and crash factors, and consequences for civilian drivers involved in fatal and nonfatal crashes with in-use and in-transport EVs. In general, drivers involved in emergency-civilian crashes (ECCs) were more often driving: straight through intersections (vs. same direction) of four-points or more (vs. not at intersection); where traffic signals were present (vs. no traffic control device); and at night (vs. midday). For nonfatal ECCs, drivers were more often driving: distracted (vs. not distracted); with vision obstructed by external objects (vs. no obstruction); on dark but lighted roads (vs. daylight); and in opposite directions (vs. same directions) of the EVs. Consequences included increased risk of injury (vs. no injury) and receiving traffic violations (vs. no violation). Fatal ECCs were associated with driving on urban roads (vs. rural), although these types of crashes were less likely to occur on dark roads (vs. daylight). The findings of this study suggest drivers may have difficulties in visually detecting EVs in different environments.

Work-related violence against educators in Minnesota: rates and risks based on hours exposed.

PROBLEM: Violence is a major occupational problem; yet, rigorous studies focused on educators to address this problem are limited. The objective was to identify educators' potential risks for physical assault (PA) and nonphysical violence (NPV), based on hours exposed. METHODS: A total of 4,731 licensed kindergarten through grade 12 Minnesota educators, identified from the Minnesota Department of Education database, participated. Specially designed mailed questionnaires (12-month recall) enabled data collection. Calculated PA and NPV rates, per 100,000 working hours, used Poisson regression. Directed acyclic graphs identified confounders for multivariable analysis, adjusted for non-response and unknown eligibility. RESULTS: The total PA rate was 5.3; PA risks increased for educators who: were non-married versus married; held master's degrees, or education specialist degrees, versus associate/bachelor's degrees; worked in public alternative and various school types, versus public schools; worked as social workers, in special education or multiple activities, versus standard classroom teaching; worked with <10, versus 10 to <25 students in the class. The total NPV rate was 26.4; subcategory rates were: threat (34.8); sexual harassment (7.6); verbal abuse (55.5); bullying (19.6). Increased risks for NPV included: 30-39 and 60-79, versus 50-59years of age; non-married versus married; working in public alternative versus public schools; working part-time or substitute, versus full-time; teaching in special education or multiple activities, versus standard classroom teaching; teaching in class sizes <10 and ≥25, versus 10-24 students; teaching in grades 3-12 and multiple grades, versus kindergarten to second grade. The investigated results for PA and NPV were similar, with a few exceptions. DISCUSSION AND IMPACT ON INDUSTRY: Results from this study provided information about factors associated with increased and decreased risks for violence against educators, based on hours worked. In addition, they provided a basis for further investigations to reduce violence against educators in the school environment.

Risk of physical assault against school educators with histories of occupational and other violence: a case-control study.

A case-control study design was used to investigate risks of work-related physical assault (PA) associated with a history of violent victimization among educators. A total of 6,469 state-licensed educators (Kindergarten - Grade 12) worked in the previous 12~months and were eligible to participate. Exposure data were collected from cases (reporting a PA event in previous 12 months, n=290) for the month before PA, and from controls (no work-related PA in previous 12 months; n=867) for a randomly selected working month. Odds ratios and 95% confidence intervals identified increased risks for educators with any prior history of work-related (17.3, 11.4-26.3) or non-work-related PA (2.0, 1.2-3.5). In addition, PA risk in the previous twelve months increased with the number of previous victimizations, and risk also increased for educators with histories of non-physical violence (work- and non work-related). The results present a compelling case for targeted interventions and further research.

Violence against educators: a population-based study.

OBJECTIVE: Identify the magnitude and risk factors for occupational physical assault (PA) and nonphysical violence (NPV) against Minnesota educators. METHODS: Among 26,000 randomly selected licensed kindergarten to grade 12 educators, 6469 eligible educators reported whether they experienced PA or NPV during the prior year. Multiple logistic regression models were based on directed acyclic graphs. RESULTS: Respective PA and NPV annual rates per 100 educators were 8.3 and 38.4. Work changes resulted among PA (13% to 20%) and NPV (22%) victims. Risks increased for master's prepared or education specialists who worked in public alternative schools and special education. Risks decreased for those working for more than 20 years, part time, and in private schools. Physical assault risk decreased when teaching grades 3 to 12 (vs kindergarten to grade 2), but NPV risk increased. CONCLUSION: Targeted efforts on specific violence risk and protective factors are essential to improve educators' work environments.

Written violence policies and risk of physical assault against Minnesota educators.

Few research studies on school violence policies use quantitative methods to evaluate the impact of policies on workplace violence. This study analyzed nine different written violence policies and their impact on work-related physical assault in educational settings. Data were from the Minnesota Educators' Study. This large, nested case control study included cases (n=372) who reported physical assaults within the last year, and controls (n=1116) who did not. Multivariate logistic regression analyses, using directed acyclic graphs, estimated risk of assault. Results of the adjusted multivariate model suggested decreased risks of physical assault were associated with the presence of policies regarding how to report sexual harassment, verbal abuse, and threat (OR 0.53; 95 per cent CI: 0.30-0.95); assurance of confidential reporting of events (OR 0.67; 95 per cent CI: 0.44-1.04); and zero tolerance for violence (OR 0.70; 95 per cent CI: 0.47-1.04).