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.

A marginal structural model approach to analyse work-related injuries: an example using data from the health and retirement study.

BACKGROUND: Biases may exist in the limited longitudinal data focusing on work-related injuries among the ageing workforce. Standard statistical techniques may not provide valid estimates when the data are time-varying and when prior exposures and outcomes may influence future outcomes. This research effort uses marginal structural models (MSMs), a class of causal models rarely applied for injury epidemiology research to analyse work-related injuries. METHODS: 7212 working US adults aged ≥50 years, obtained from the Health and Retirement Study sample in the year 2004 formed the study cohort that was followed until 2014. The analyses compared estimates measuring the associations between physical work requirements and work-related injuries using MSMs and a traditional regression model. The weights used in the MSMs, besides accounting for time-varying exposures, also accounted for the recurrent nature of injuries. RESULTS: The results were consistent with regard to directionality between the two models. However, the effect estimate was greater when the same data were analysed using MSMs, built without the restriction for complete case analyses. CONCLUSIONS: MSMs can be particularly useful for observational data, especially with the inclusion of recurrent outcomes as these can be incorporated in the weights themselves.

The impact of different approaches to exposure assessment on understanding non-malignant respiratory disease risk in taconite miners.

INTRODUCTION: We examined the association between cumulative silica exposures in taconite mining and non-malignant respiratory disease (NMRD) using a comprehensive assessment of current and historical exposure measurements in a cross-sectional study of Minnesota taconite mining workers. We also explored the impact of exposure measurement methods by comparing estimated exposure risk from two different exposure measurement modeling approaches. METHODS: Miners were screened with an occupational and medical history questionnaire, spirometry testing and chest x-rays per ILO guidelines. Current and historical occupational exposure assessments were obtained, the former measuring about 679 personal samples over the period of the study for respirable dusts, including silica, in 28 major job functions. Cumulative silica exposure ((mg/m3) × years) was estimated as a cumulative product of time worked and year-specific silica job exposure concentrations. Chest x-ray abnormalities were based on B-reader agreement with a third B-reader for arbitration. Forced vital capacity (FVC) less than lower limits of normal for age, height, race and gender was used to determine spirometric restrictive ventilatory defect (RVD). Prevalence ratios (PR) of exposure-outcome associations, with 95% confidence intervals (CI), were estimated using multivariate Poisson regression. RESULTS: Cumulative silica exposure was associated with RVD prevalence (PR = 1.41, 95% CI = 1.09-1.81) and prevalence of parenchymal abnormalities on chest x-ray (PR = 1.30, 95% CI = 1.00-1.69) using exposure estimates based primarily on current study measurements, and assuming unchanged historical exposure trend. Conversely, when exposures were defined incorporating available actual historical values, no associations were observed between silica exposure and either RVD (PR = 0.76, 95% CI = 0.41-1.40) or parenchymal (PR = 0.87, 95% CI = 0.45-1.70) outcomes. CONCLUSIONS: This study demonstrated that the estimated association between silica dust exposure and lung disease is highly sensitive to the approach used to estimate cumulative exposure. Cumulative values based on conservative estimates of past exposure, modeled from recently measured respirable silica, showed an association with restriction RVD on spirometry. Silica exposure was also significantly associated with increased parenchymal findings on chest x-ray using this approach. Conversely, these findings were absent when actual available historical data was used to estimate cumulative silica exposure. These differences highlight the challenges with estimating occupational dust exposure, the potential impact on calculated exposure risk and the need for long term quality exposure data gathering in industries prone to risk from inhaled respirable dusts.

Student-inflicted injuries to staff in schools: comparing risk between educators and non-educators.

OBJECTIVE: Student-inflicted injury to staff in the educational services sector is a growing concern. Studies on violence have focused on teachers as victims, but less is known about injuries to other employee groups, particularly educational assistants. Inequities may be present, as educational assistants and non-educators may not have the same wage, benefits, training and employment protections available to them as professional educators. We identified risk factors for student-related injury and their characteristics among employees in school districts. METHODS: Workers' compensation data were used to identify incidence and severity of student-related injury. Rates were calculated using negative binomial regression; risk factors were identified using multivariate models to calculate rate ratios (RR) and 95% CIs. RESULTS: Over 26% of all injuries were student-related; 8% resulted in lost work time. Special and general education assistants experienced significantly increased risk of injury (RR=6.0, CI 5.05 to 7.15; RR=2.07, CI 1.40 to 3.07) as compared with educators. Risk differed by age, gender and school district type. Text analyses categorised student-related injury. It revealed injury from students acting out occurred most frequently (45.4%), whereas injuries involving play with students resulted in the highest percentage of lost-time injuries (17.7%) compared with all interaction categories. CONCLUSION: Student-inflicted injury to staff occurs frequently and can be severe. Special education and general assistants bear the largest burden of injury compared with educators. A variety of prevention techniques to reduce injury risk and severity, including policy or environmental modifications, may be appropriate. Equal access to risk reduction methods for all staff should be prioritised.

Comparing disability and return to work outcomes between alternative and traditional workers' compensation programs.

BACKGROUND: The Union Construction Workers' Compensation Program (UCWCP) was developed in 1996 as an alternative workers' compensation arrangement. The program includes use of a preapproved medical and rehabilitation network and alternative dispute resolution (ADR), and prioritizes a quick and safe return-to-work. The aim of this study is to determine if differences in recovery-related outcomes exist between UCWCP and the statutory workers' compensation system (SWCS). METHODS: Claims data from 2003 to 2016 were classified as processed through UCWCP or SWCS. Outcomes included: temporary total disability (TTD), vocational rehabilitation (VR), claim duration and costs, and permanent partial disability (PPD). The relative risk of incurring TTD, VR, and PPD in UCWCP vs SWCS was calculated using log-binomial regression. Linear regression examined the relationship between programs and continuous outcomes including costs and duration. Estimates were adjusted for age, sex, wage, and severity. RESULTS: The UCWCP processed 15.8% of claims; higher percentages of UCWCP claimants were older and earned higher wages. Results point to positive findings of decreased TTD incidence and cost, lower risk of TTD extending over time, higher likelihood of VR participation, and less attorney involvement and stipulation agreements associated with UCWCP membership. Differences were more apparent in workers who suffered permanent physical impairment. CONCLUSION: Findings suggest that the defining programmatic elements of the UCWCP, including its medical provider and rehabilitation network and access to ADR, have been successful in their aims. Claims with increased severity exhibited more pronounced differences vs SWCS, potentially due, in part, to greater use of programmatic elements.

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.

A case-control study of mesothelioma in Minnesota iron ore (taconite) miners.

OBJECTIVES: An excess of mesothelioma has been observed in iron ore miners in Northeastern Minnesota. Mining and processing of taconite iron ore generate exposures that include elongate mineral particles (EMPs) of amphibole and non-amphibole origin. We conducted a nested case-control study of mesothelioma in a cohort of 68,737 iron ore miners (haematite and taconite ore miners) to evaluate the association between mesothelioma, employment and EMP exposures from taconite mining. METHODS: Mesothelioma cases (N=80) were identified through the Minnesota Cancer Surveillance System (MCSS) and death certificates. Four controls of similar age were selected for each case with 315 controls ultimately eligible for inclusion. Mesothelioma risk was evaluated by estimating rate ratios and 95% CIs with conditional logistic regression in relation to duration of taconite industry employment and cumulative EMP exposure [(EMP/cc)×years], defined by the National Institute for Occupational Safety and Health (NIOSH) 7400 method. Models were adjusted for employment in haematite mining and potential exposure to commercial asbestos products used in the industry. RESULTS: All mesothelioma cases were male and 57 of the cases had work experience in the taconite industry. Mesothelioma was associated with the number of years employed in the taconite industry (RR=1.03, 95% CI 1.00 to 1.06) and cumulative EMP exposure (RR=1.10, 95% CI 0.97 to -1.24). No association was observed with employment in haematite mining. CONCLUSIONS: These results support an association between mesothelioma and employment duration and possibly EMP exposure in taconite mining and processing. The type of EMP was not determined. The potential role of commercial asbestos cannot be entirely ruled out.

Occupational exposures and lung cancer risk among Minnesota taconite mining workers.

OBJECTIVE: To examine the association between employment duration, elongate mineral particle (EMP) exposure, silica exposure and the risk of lung cancer in the taconite mining industry. METHODS: We conducted a nested case-control study of lung cancer within a cohort of Minnesota taconite iron mining workers employed by any of the mining companies in operation in 1983. Lung cancer cases were identified by vital records and cancer registry data through 2010. Two age-matched controls were selected from risk sets of cohort members alive and lung cancer free at the time of case diagnosis. Calendar time-specific exposure estimates were made for every job and were used to estimate workers' cumulative exposures. ORs and 95% CIs were estimated using conditional logistic regression. We evaluated total lung cancer risk and risk of histological subtype by total work duration and by cumulative EMP, and silica exposure by quartile of the exposure distribution. RESULTS: A total of 1706 cases and 3381 controls were included in the analysis. After adjusting for work in haematite mining, asbestos exposure and sex, the OR for total duration of employment was 0.99 (95% CI 0.96 to 1.01). The ORs for quartile 4 versus 1 of EMP and silica exposure were 0.82 (95% CI 0.57 to 1.19) and 0.97 (95% CI 0.70 to 1.35), respectively. The risk of each histological subtype of lung cancer did not change with increasing exposure. CONCLUSIONS: This study suggests that the estimated taconite mining exposures do not increase the risk of developing lung cancer.

Impacts of COVID-19 on Stress in Middle School Teachers and Staff in Minnesota: An Exploratory Study Using Random Forest Analysis.

While the COVID-19 pandemic has negatively impacted many occupations, teachers and school staff have faced unique challenges related to remote and hybrid teaching, less contact with students, and general uncertainty. This study aimed to measure the associations between specific impacts of the COVID-19 pandemic and stress levels in Minnesota educators. A total of 296 teachers and staff members from eight middle schools completed online surveys between May and July of 2020. The Epidemic Pandemic Impacts Inventory (EPII) measured the effects of the COVID-19 pandemic according to nine domains (i.e., Economic, Home Life). The Kessler-6 scale measured non-specific stress (range: 0-24), with higher scores indicating greater levels of stress. Random forest analysis determined which items of the EPII were predictive of stress. The average Kessler-6 score was 6.8, indicating moderate stress. Three EPII items explained the largest amount of variation in the Kessler-6 score: increase in mental health problems or symptoms, hard time making the transition to working from home, and increase in sleep problems or poor sleep quality. These findings indicate potential areas for intervention to reduce employee stress in the event of future disruptions to in-person teaching or other major transitions during dynamic times.

Risk factors for occupational injuries in schools among educators and support staff.

INTRODUCTION: School districts employ a large number of employees who work in educational (e.g., teachers) or other support roles, including educational assistants, custodians, food service, bus drivers, and community and recreation workers. District employees perform a wide array of job tasks and experience a wide spectrum of work-related risks and injuries. METHODS: Workers' compensation data were coupled with Minnesota Department of Education district employee denominator data to evaluate risk factors for injury and severity. Variables included district location and type, employee job classification, age, and gender. Rates of injury and rate ratios were calculated to measure comparative injury risk using negative binomial regression and 95% confidence internals. Incidence and frequency of injury cause, nature, and body part we calculated. RESULTS: Saint Paul and Minneapolis metropolitan area (versus non-metro) districts had higher risk (RR = 1.35, 95%CI = 1.18-1.54) of employee injuries. All job classifications in support roles had increased risk of injury claims versus educators, however food service (RR = 5.14, 95%CI = 4.61-5.74), custodial (RR = 3.85, 95%CI = 3.41-4.34), and transportation (RR = 4.15, 95%CI = 3.38-5.10) exhibited the highest comparative risk to educators; significant risk of lost-time injury was also present in these workers. Males and females had similar risk of injury for all claims, however males had elevated risk of lost-time injury (RR = 1.46, 95%CI = 1.26-1.69) versus females. All age groups >41-years-old exhibited increased risk of injury as compared to 31-40-year-olds. The magnitude of lost-time injury risk also increased with age. Falls and slips (29.1%), strains/sprains/ruptures (45.2%), and upper extremities (31.3%) most frequent cause, nature, and body part injured, respectively. CONCLUSIONS: Characteristics of districts, schools, workers, and their jobs tasks and hazards vary. Many categories of support staff in schools have elevated risk of injury, including lost-time injury, as compared to educators. Practical Applications: Injury prevention in schools should be approached by targeting job classifications; high risk jobs can be prioritized for prevention.

Characteristics and Risk Factors for Electric Scooter-Related Crashes and Injury Crashes among Scooter Riders: A Two-Phase Survey Study.

Electric scooters (or e-scooters) are among the most popular micromobility options that have experienced an enormous expansion in urban transportation systems across the world in recent years. Along with the increased usage of e-scooters, the increasing number of e-scooter-related injuries has also become an emerging global public health concern. However, little is known regarding the risk factors for e-scooter-related crashes and injury crashes. This study consisted of a two-phase survey questionnaire administered to a cohort of e-scooter riders (n = 210), which obtained exposure information on riders' demographics, riding behaviors (including infrastructure selection), helmet use, and other crash-related factors. The risk ratios of riders' self-reported involvement in an e-scooter-related crash (i.e., any crash versus no crash) and injury crash (i.e., injury crash versus non-injury crash) were estimated across exposure subcategories using the Negative Binomial regression approach. Males and frequent users of e-scooters were associated with an increased risk of e-scooter-related crashes of any type. For the e-scooter-related injury crashes, more frequently riding on bike lanes (i.e., greater than 25% of the time), either protected or unprotected, was identified as a protective factor. E-scooter-related injury crashes were more likely to occur among females, who reported riding on sidewalks and non-paved surfaces more frequently. The study may help inform public policy regarding e-scooter legislation and prioritize efforts to establish suitable road infrastructure for improved e-scooter riding safety.

Biomarker measurements of concurrent exposure to multiple environmental chemicals and chemical classes in children.

Concern is mounting that children from disadvantaged, low-income neighborhoods are likely to be both more exposed to chemical hazards and more susceptible to related adverse health effects. This article reports measurements of >75 individual biomarkers spanning 7 chemical/pollutant classes in blood and urine from more than 100 children living in a socioeconomically disadvantaged and ethnically diverse area of south Minneapolis, MN. Results indicate that a significant proportion of children in the study were at the high end of the exposure distribution compared to national reference ranges for a variety of environmental chemicals and/or their metabolites, including phthalates, organochlorine pesticides, organophosphate pesticides, metals, polychlorinated biphenyls, and volatile organic compounds. In addition, levels of cotinine in urine indicate that more than half the children were regularly exposed to environmental tobacco smoke, with the upper 10th percentile exposed to relatively high concentrations.

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.

The association between janitor physical workload, mental workload, and stress: The SWEEP study.

BACKGROUND: Approximately 2.38 million janitors are employed in the U.S. While high physical workload may explain a lost-work days rate 2.7 times greater than other occupations, little is known about the association between janitors' physical workload, mental workload, and stress. OBJECTIVE: The objective of this study was to assess the associations between physical (ergonomic) and mental workload exposures and stress outcomes among janitors. METHODS: Questionnaire data, focused on ergonomic workload, mental workload and stress, were collected from Minnesota janitors for a one-year period. Physical workload was assessed with Borg Scales and Rapid Entire Body Assessments (REBA). Mental workload assessment utilized the NASA Task Load Index (TLX). Stress assessments utilized single-item ordinal stress scale (SISS) and Perceived Stress Scale-4 (PSS-4) measures. Descriptive and multivariable analyses, including bias adjustment, were conducted. RESULTS: Odds ratios (OR) and 95% confidence intervals (CI) for ergonomic workload (task frequency) effects on SISS were: REBA (1.18 OR, 1.02-1.37 CI); Borg (1.25 OR, 1.00-1.56 CI); combined REBA and Borg (1.10 OR, 1.01-1.20 CI). Mental workload was associated with higher PSS-4 levels (0.15 Mean Difference, 0.08-0.22 CI) and a 3% increased risk for each one-unit increase in the SISS scale (1.03 OR, 1.02-1.05 CI). CONCLUSIONS: This research demonstrated a moderate effect of physical and mental workloads on stress among janitors.

Parents' safety beliefs and childhood agricultural injury.

BACKGROUND: This study examined potential associations between parental safety beliefs and children's chore assignments or risk of agricultural injury. METHODS: Analyses were based on nested case-control data collected by the 1999 and 2001 Regional Rural Injury Study-II (RRIS-II) surveillance efforts. Cases (n = 425, reporting injuries) and controls (n = 1,886, no injuries; selected using incidence density sampling) were persons younger than 20 years of age from Midwestern agricultural households. A causal model served as the basis for multivariate data analysis. RESULTS: Decreased risks of injury (odds ratio [OR] and 95% confidence intervals [CI]) were observed for working-aged children with "moderate," compared to "very strict" parental monitoring (0.60; 0.40-0.90), and with parents believing in the importance of physical (0.80; 0.60-0.95) and cognitive readiness (0.70, 0.50-0.90, all children; 0.30, 0.20-0.50, females) when assigning new tasks. Parents' safety beliefs were not associated with chore assignments. CONCLUSIONS: Parents' safety beliefs were associated with reduced risk of childhood agricultural injury; the association was not mediated by chore assignments.

Detection of organophosphate pesticides using a prototype liquid crystal monitor.

The precision and accuracy of a prototype wearable liquid crystal monitor (LCM) for the measurement of airborne organophosphate pesticide concentrations was explored in a series of laboratory experiments. LCM response to vapor-phase and aerosol diazinon was compared to concentrations obtained using a standard reference method (NIOSH 5600) at concentrations ranging from approximately 8 to 108 ppb (parts per billion) over durations of 2 to 80 hours. Temperature ( approximately 25, 30, and 35 degrees C) and relative humidity (15, 50, and 85%) were varied to estimate the effect of these factors on LCM performance. The LCM response to vapor phase pesticide exposure was linear for concentrations in the range of 8-20 ppb. At exposure concentrations above approximately 20 ppb, however, there was a decline in monitor response and measurement precision. Elevated temperatures improved diazinon vapor-only measurement precision, while increased relative humidity reduced LCM response at the extremes of tested temperatures. Compared to vapor-only exposures, the LCM was less sensitive to diazinon aerosol concentrations, but displayed reasonable precision over a relatively large range of exposures (29 to 1190 ppb-hr). Further efforts to characterize temperature and humidity effects and improve low-end sensitivity would likely provide a portable personal exposure monitor or environmental sensor for this widely used class of pesticides.

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.

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.