Why does the adverse effect of inappropriate MRI for LBP vary by geographic location? An exploratory analysis.

BACKGROUND: Early magnetic resonance imaging (eMRI) for nonspecific low back pain (LBP) not adherent to clinical guidelines is linked with prolonged work disability. Although the prevalence of eMRI for occupational LBP varies substantially among states, it is unknown whether the risk of prolonged disability associated with eMRI varies according to individual and area-level characteristics. The aim was to explore whether the known risk of increased length of disability (LOD) associated with eMRI scanning not adherent to guidelines for occupational LBP varies according to patient and area-level characteristics, and the potential reasons for any observed variations. METHODS: A retrospective cohort of 59,360 LBP cases from 49 states, filed between 2002 and 2008, and examined LOD as the outcome. LBP cases with at least 1 day of work disability were identified by reviewing indemnity service records and medical bills using a comprehensive list of codes from the International Classification of Diseases, Ninth Edition (ICD-9) indicating LBP or nonspecific back pain, excluding medically complicated cases. RESULTS: We found significant between-state variations in the negative impact of eMRI on LOD ranging from 3.4 days in Tennessee to 14.8 days in New Hampshire. Higher negative impact of eMRI on LOD was mainly associated with female gender, state workers' compensation (WC) policy not limiting initial treating provider choice, higher state orthopedic surgeon density, and lower state MRI facility density. CONCLUSION: State WC policies regulating selection of healthcare provider and structural factors affecting quality of medical care modify the impact of eMRI not adherent to guidelines. Targeted healthcare and work disability prevention interventions may improve work disability outcomes in patients with occupational LBP.

Employee acceptance of wearable technology in the workplace.

Wearable technology has many industrial applications. Optimal use adherence and outcomes largely depend on employee acceptance of the technology. This study determined factors that predict employee acceptance of wearables. An online survey of 1273 employed adults asked about demographics, job and organizational characteristics, experience with and beliefs about wearables, and willingness to use wearables. Use cases focused on workplace safety elicited the highest acceptance. An employee's performance expectancy and their organizational safety climate were common predictors of acceptance across use cases. Positive past experiences coincided with involving employees in choosing the device and adequately informing them about data use. Organizations intending to implement wearable technology should (a) focus its use on improving workplace safety, (b) advance a positive safety climate, (c) ensure sufficient evidence to support employees' beliefs that the wearable will meet its objective, and (d) involve and inform employees in the process of selecting and implementing wearable technology.

Circumstances of fall-related injuries by age and gender among community-dwelling adults in the United States.

INTRODUCTION: Falls are the leading cause of injury in almost all age-strata in the U.S. However, fall-related injuries (FI) and their circumstances are under-studied at the population level, particularly among young and middle-aged adults. This study examined the circumstances of FI among community-dwelling U.S. adults, by age and gender. METHODS: Narrative texts of FI from the National Health Interview Survey (1997-2010) were coded using a customized taxonomy to assess place, activity, initiating event, hazards, contributing factors, fall height, and work-relatedness of FI. Weighted proportions and incidence rates of FI were calculated across six age-gender groups (18-44, 45-64, 65+ years; women, men). RESULTS: The proportion of FI occurring indoors increased with age in both genders (22%, 30%, and 48% among men, and 40%, 49% and 62% among women for 18-44, 45-64, 65+ age-groups, respectively). In each age group the proportion of indoor FI was higher among women as compared to men. Among women, using the stairs was the second leading activity (after walking) at the time of FI (19%, 14% and 10% for women in 18-44, 45-64, 65+ age groups, respectively). FI associated with tripping increased with age among both genders, and women were more likely to trip than men in every age group. Of all age-gender groups, the rate of FI while using ladders was the highest among middle-aged men (3.3 per 1000 person-year, 95% CI 2.0, 4.5). Large objects, stairs and steps, and surface contamination were the three most common hazards noted for 15%, 14% and 13% of fall-related injuries, respectively. CONCLUSIONS: The rate and the circumstances of FI differ by age and gender. Understanding these differences and obtaining information about circumstances could be vital for developing effective interventions to prevent falls and FI.

Regional socioeconomic disparities in outcomes for workers with low back pain in the United States.

BACKGROUND: Although regional socioeconomic (SE) factors have been associated with worse health outcomes, prior studies have not addressed important confounders or work disability. METHODS: A national sample of 59 360 workers' compensation (WC) cases to evaluate impact of regional SE factors on medical costs and length of disability (LOD) in occupational low back pain (LBP). RESULTS: Lower neighborhood median household incomes (MHI) and higher state unemployment rates were associated with longer LOD. Medical costs were lower in states with more workers receiving Social Security Disability, and in areas with lower MHI, but this varied in magnitude and direction among neighborhoods. Medical costs were higher in more urban, more racially diverse, and lower education neighborhoods. CONCLUSIONS: Regional SE disparities in medical costs and LOD occur even when health insurance, health care availability, and indemnity benefits are similar. Results suggest opportunities to improve care and disability outcomes through targeted health care and disability interventions.

Combining statistics from two national complex surveys to estimate injury rates per hour exposed and variance by activity in the USA.

BACKGROUND: A common issue in descriptive injury epidemiology is that in order to calculate injury rates that account for the time spent in an activity, both injury cases and exposure time of specific activities need to be collected. In reality, few national surveys have this capacity. To address this issue, we combined statistics from two different national complex surveys as inputs for the numerator and denominator to estimate injury rate, accounting for the time spent in specific activities and included a procedure to estimate variance using the combined surveys. METHODS: The 2010 National Health Interview Survey (NHIS) was used to quantify injuries, and the 2010 American Time Use Survey (ATUS) was used to quantify time of exposure to specific activities. The injury rate was estimated by dividing the average number of injuries (from NHIS) by average exposure hours (from ATUS), both measured for specific activities. The variance was calculated using the 'delta method', a general method for variance estimation with complex surveys. RESULTS: Among the five types of injuries examined, 'sport and exercise' had the highest rate (12.64 injuries per 100 000 h), followed by 'working around house/yard' (6.14), driving/riding a motor vehicle (2.98), working (1.45) and sleeping/resting/eating/drinking (0.23). The results show a ranking of injury rate by activity quite different from estimates using population as the denominator. CONCLUSIONS: Our approach produces an estimate of injury risk which includes activity exposure time and may more reliably reflect the underlying injury risks, offering an alternative method for injury surveillance and research.

Working multiple jobs over a day or a week: Short-term effects on sleep duration.

Approximately 10% of the employed population in the United States works in multiple jobs. They are more likely to work long hours and in nonstandard work schedules, factors known to impact sleep duration and quality, and increase the risk of injury. In this study we used multivariate regression models to compare the duration of sleep in a 24-hour period between workers working in multiple jobs (MJHs) with single job holders (SJHs) controlling for other work schedule and demographic factors. We used data from the Bureau of Labor Statistics US American Time Use Survey (ATUS) pooled over a 9-year period (2003-2011). We found that MJHs had significantly reduced sleep duration compared with SJHs due to a number of independent factors, such as working longer hours and more often late at night. Male MJHs, working in their primary job or more than one job on the diary day, also had significantly shorter sleep durations (up to 40 minutes less on a weekend day) than male SJHs, even after controlling for all other factors. Therefore, duration of work hours, time of day working and duration of travel for work may not be the only factors to consider when understanding if male MJHs are able to fit in enough recuperative rest from their busy schedule. Work at night had the greatest impact on sleep duration for females, reducing sleep time by almost an hour compared with females who did not work at night. We also hypothesize that the high frequency or fragmentation of non-leisure activities (e.g. work and travel for work) throughout the day and between jobs may have an additional impact on the duration and quality of sleep for MJHs.

Falls and Fall-Related Injuries among Community-Dwelling Adults in the United States.

INTRODUCTION: Falls are the leading cause of unintentional injuries in the U.S.; however, national estimates for all community-dwelling adults are lacking. This study estimated the national incidence of falls and fall-related injuries among community-dwelling U.S. adults by age and gender and the trends in fall-related injuries across the adult life span. METHODS: Nationally representative data from the National Health Interview Survey (NHIS) 2008 Balance and Dizziness supplement was used to develop national estimates of falls, and pooled data from the NHIS was used to calculate estimates of fall-related injuries in the U.S. and related trends from 2004-2013. Costs of unintentional fall-related injuries were extracted from the CDC's Web-based Injury Statistics Query and Reporting System. RESULTS: Twelve percent of community-dwelling U.S. adults reported falling in the previous year for a total estimate of 80 million falls at a rate of 37.2 falls per 100 person-years. On average, 9.9 million fall-related injuries occurred each year with a rate of 4.38 fall-related injuries per 100 person-years. In the previous three months, 2.0% of older adults (65+), 1.1% of middle-aged adults (45-64) and 0.7% of young adults (18-44) reported a fall-related injury. Of all fall-related injuries among community-dwelling adults, 32.3% occurred among older adults, 35.3% among middle-aged adults and 32.3% among younger adults. The age-adjusted rate of fall-related injuries increased 4% per year among older women (95% CI 1%-7%) from 2004 to 2013. Among U.S. adults, the total lifetime cost of annual unintentional fall-related injuries that resulted in a fatality, hospitalization or treatment in an emergency department was 111 billion U.S. dollars in 2010. CONCLUSIONS: Falls and fall-related injuries represent a significant health and safety problem for adults of all ages. The findings suggest that adult fall prevention efforts should consider the entire adult lifespan to ensure a greater public health benefit.

Length of Disability and Medical Costs in Low Back Pain: Do State Workers' Compensation Policies Make a Difference?

OBJECTIVE: The aim of the study was to examine the impact of state workers' compensation (WC) policies regarding wage replacement and medical benefits on medical costs and length of disability (LOD) in workers with low back pain (LBP). METHODS: Retrospective cohort analysis of LBP claims from 49 states (n = 59,360) filed between 2002 and 2008, extracted from a large WC administrative database. RESULTS: Longer retroactive periods and state WC laws allowing treating provider choice were associated with higher medical costs and longer LOD. Limiting the option to change providers and having a fee schedule were associated with longer LOD, except that allowing a one-time treating provider change was associated with lower medical costs and shorter LOD. CONCLUSIONS: WC policies about wage replacement and medical treatment appear to be associated with WC LBP outcomes, and might represent opportunities to improve LOD and reduce medical costs in occupational LBP.

Differences in time use and activity patterns when adding a second job: implications for health and safety in the United States.

OBJECTIVES: We compared work and lifestyle activities for workers who work in 1 job with those who work in multiple jobs during a 1-week period. METHODS: We used information from the 2003-2011 American Time Use Survey to classify workers into 6 work groups based on whether they were a single (SJH) or multiple (MJH) job holder and whether they worked their primary, other, multiple, or no job on the diary day. RESULTS: The MJHs often worked 2 part-time jobs (20%), long weekly hours (27% worked 60+ hours), and on weekends. The MJHs working multiple jobs on the diary day averaged more than 2 additional work hours (2.25 weekday, 2.75 weekend day; P < .05), odd hours (more often between 5 pm and 7 am), with more work travel time (10 minutes weekday, 9 minutes weekend day; P < .05) and less sleep (-45 minutes weekday, -62 minutes weekend day; P < .05) and time for other household (P < .05) and leisure (P < .05) activities than SJHs. CONCLUSIONS: Because of long work hours, long daily commutes, multiple shifts, and less sleep and leisure time, MJHs may be at heightened risk of fatigue and injury.

Work in multiple jobs and the risk of injury in the US working population.

OBJECTIVES: We compared the risk of injury for multiple job holders (MJHs) with that for single job holders (SJHs). METHODS: We used information from the National Health Interview Survey for the years 1997 through 2011 to estimate the rate of multiple job holding in the United States and compared characteristics and rates of self-reported injury (work and nonwork) for SJHs versus MJHs. RESULTS: Approximately 8.4% of those employed reported working more than 1 job in the week before the interview. The rate of work and nonwork injury episodes per 100 employed workers was higher for MJHs than for SJHs (4.2; 95% confidence interval [CI] = 3.5, 4.8; vs 3.3; 95% CI = 3.1, 3.5 work injuries and 9.9; 95% CI = 8.9, 10.9; vs 7.4; 95% CI = 7.1, 7.6 nonwork injuries per 100 workers, respectively). When calculated per 100 full-time equivalents (P < .05), the rate ratio remained higher for MJHs. CONCLUSIONS: Our findings suggest that working in multiple jobs is associated with an increased risk of an injury, both at work and not at work, and should be considered in injury surveillance.

The utility of injury narratives for prioritising future prevention activities in small and medium enterprises in rural Vietnam.

OBJECTIVES: Injuries are a leading cause of work-related disability and death in rapidly developing countries such as Vietnam. The authors' objective was to demonstrate the utility of detailed injury narratives, derived from a household survey, in providing information on the determinants of work-related injuries to inform potential intervention targets. METHODS: In a cross-sectional survey administered to 2615 households of a rapidly developing community of Vietnam where many workers engage in both agriculture and industrial work, the authors collected information about self-reported work-related injuries, annual hours worked in each industry and narrative text describing the circumstances of each injury. The authors used a customised coding taxonomy to describe injury scenarios. RESULTS: Several intervention themes emerged, including the implementation of machine guarding, the use of cut resistant gloves and safety glasses which would benefit the small- and medium-sized enterprises. Calculation of incidence rates using full-time equivalents, stratified by work group, provided some unexpected observations of the risks of working in agriculture; workers who work in agriculture in addition to another industry are at an increased risk of fatigue or overexertion and other consequences of working too hard in their agricultural activities. CONCLUSIONS: A lack of aggregate injury statistics makes it difficult for the owners of small- and medium-sized enterprises to recognise a priori the most effective safety interventions. This analysis of detailed injury narratives with an appropriate taxonomic basis offers the ability to focus on the level of cause, activity and source and may inform the choice of various potential interventions at the workplace or enterprise level.

A structural equation modeling approach to fatigue-related risk factors for occupational injury.

Occupational injury is associated with numerous individual and work-related risk factors, including long working hours and short sleep duration; however, the complex mechanisms causing such injuries are not yet fully understood. The authors used structural equation modeling (SEM) as a novel approach to examine fatigue-related direct and indirect potential risk factors for occupational injury. The study sample contained 89,366 employed workers from the National Health Interview Survey (pooled across 6 years, 2004-2009), an annual survey of a representative cross-sectional sample of the US population. Direct and indirect effects of weekly hours worked and usual sleep duration on occupational injuries were modeled using SEM procedures for dichotomous outcomes and a complex sampling design. Confounding and mediating effects of gender, age, race/ethnicity, occupation, industry, type of pay, body mass index (BMI), and psychological distress were simultaneously examined. Long working hours and short sleep duration independently increased the risk of injury. Additional direct risk factors were gender, occupation, type of pay, and BMI. At the same time, sleep duration mediated the adverse relations of long working hours, high psychological distress, and high BMI with injury. These findings indicate that SEM is a useful approach with which to examine dichotomous outcomes and indirect effects in complex samples, and it offers a comprehensive new model of injury prediction.

Independent effects of sleep duration and body mass index on the risk of a work-related injury: evidence from the US National Health Interview Survey (2004-2010).

Fatigue has been linked to adverse safety outcomes, and poor quality or decreased sleep has been associated with obesity (higher body mass index, BMI). Additionally, higher BMI is related to an increased risk for injury; however, it is unclear whether BMI modifies the effect of short sleep or has an independent effect on work-related injury risk. To answer this question, the authors examined the risk of a work-related injury as a function of total daily sleep time and BMI using the US National Health Interview Survey (NHIS). The NHIS is an in-person household survey using a multistage, stratified, clustered sample design representing the US civilian population. Data were pooled for the 7-yr survey period from 2004 to 2010 for 101 891 "employed" adult subjects (51.7%; 41.1 ± yrs of age [mean ± SEM]) with data on both sleep and BMI. Weighted annualized work-related injury rates were estimated across a priori defined categories of BMI: healthy weight (BMI: <25), overweight (BMI: 25-29.99), and obese (BMI: ≥30) and also categories of usual daily sleep duration: <6, 6-6.99, 7-7.99, 8-8.99, and ≥9 h. To account for the complex sampling design, including stratification, clustering, and unequal weighting, weighted multiple logistic regression was used to estimate the risk of a work-related injury. The initial model examined the interaction among daily sleep duration and BMI, controlling for weekly working hours, age, sex, race/ethnicity, education, type of pay, industry, and occupation. No significant interaction was found between usual daily sleep duration and BMI (p = .72); thus, the interaction term of the final logistic model included these two variables as independent predictors of injury, along with the aforementioned covariates. Statistically significant covariates (p ≤ .05) included age, sex, weekly work hours, occupation, and if the worker was paid hourly. The lowest categories of usual sleep duration (<6 and 6-6.9 h) showed significantly (p ≤ .05) elevated injury risks than the referent category (7-8 h sleep), whereas sleeping >7-8 h did not significantly elevate risk. The adjusted injury risk odds ratio (OR) for a worker with a usual daily sleep of <6 h was 1.86 (95% confidence interval [CI]: 1.37-2.52), and for 6-6.9 h it was 1.46 (95% CI: 1.18-1.80). With regards to BMI, the adjusted injury risk OR comparing workers who were obese (BMI: ≥30) to healthy weight workers (BMI: <25) was 1.34 (95% CI: 1.09-1.66), whereas the risk in comparing overweight workers (BMI: 25-29.99) to healthy weight risk was elevated, but not statistically significant (OR = 1.08; 95% CI: .88-1.33). These results from a large representative sample of US workers suggest increase in work-related injury risk for reduced sleep regardless of worker's body mass. However, being an overweight worker also increases work-injury risk regardless of usual daily sleep duration. The independent additive risk of these factors on work-related injury suggests a substantial, but at least partially preventable, risk.

Gender differences in the effect of weekly working hours on occupational injury risk in the United States working population.

OBJECTIVES: Long working hours can lead to an accumulation in fatigue that may increase worker's risk of injury. However, it is not known if this association is different for men and women. Our aim was, therefore, to investigate gender differences in the effect of weekly working hours on occupational injury risk. METHODS: The US National Health Interview Survey is a clustered, stratified, cross-sectional sample representative of the US population, collected using in-household interviews. We pooled seven years of data (2004-2010) comprising 96 915 employed workers. Annualized injury rates per 100 workers were estimated for men and women in categories of weekly working hours (<30, 31-40, 41-50, >50 hours/week). Additionally, injury risk was predicted using weighted logistic regression models by weekly working hour categories, stratified by gender, including age, ethnicity, education, type of pay, occupation, body mass index, usual sleep duration, and psychological distress as covariates. RESULTS: Of 96 915 workers, 705 (0.75%) reported an injury in the last 3 months. Injury rates were higher among men and increased with increasing working hours for both genders. However, results of the adjusted logistic regression model indicated an interactive effect of working hours and gender on injury risk [odds ratio (OR) 1.02, 95% confidence interval (95% CI) 1.00-1.03). Injury risk increased among women working 41-50 hours/week (OR 1.51, 95% CI 1.03-2.21) and >50 hours/week (OR 1.69, 95% CI 1.06-2.70) compared to 31-40 hours/week but not among men. CONCLUSIONS: The findings indicate an increase in injury risk with increasing working hours among women but not men.

Occupational injuries in a commune in rural Vietnam transitioning from agriculture to new industries.

OBJECTIVES: We explored the impact on work-related injuries of workers splitting time between industry and agriculture, a common situation in developing countries. METHODS: In 2005, we administered a cross-sectional survey to 2615 households of Xuan Tien, a developing rural community of Vietnam, regarding self-reported injuries and hours worked for 1 year. We defined groups as working in industry, agriculture, or a mix of both. RESULTS: Overlapping employment (part time in agriculture and up to full time in industry) increased the risk of injury in both agricultural and industrial work. This pattern held across all work groups defined by the relative amount of time worked in agriculture. Those working fewer than 500 hours annually in agriculture had an agricultural injury rate (872 per 1000 full-time equivalents) that was more than 4 times higher than the average rate overall (203 per 1000) and the rate for workers employed only in industry (178 per 1000). CONCLUSIONS: Working in agriculture for short durations while working in industry increased the risk of injury substantially in both types of work.

Daily sleep, weekly working hours, and risk of work-related injury: US National Health Interview Survey (2004-2008).

The impact on health and safety of the combination of chronic sleep deficits and extended working hours has received worldwide attention. Using the National Health Interview Survey (NHIS), an in-person household survey using a multistage, stratified, clustered sample design representing the US civilian, non-institutionalized population, the authors estimated the effect of total daily self-reported sleep time and weekly working hours on the risk of a work-related injury. During the survey period 2004-2008, 177,576 persons (ages 18-74) sampled within households reported that they worked at a paid job the previous week and reported their total weekly work hours. A randomly selected adult in each household (n = 75,718) was asked to report his/her usual (average) total daily sleep hours the prior week; complete responses were obtained for 74,415 (98.3%) workers. Weighted annualized work-related injury rates were then estimated across a priori defined categories of both average total daily sleep hours and weekly working hours. To account for the complex sampling design, weighted multiple logistic regression was used to independently estimate the risk of a work-related injury for categories of usual daily sleep duration and weekly working hours, controlling for important covariates and potential confounders of age, sex, race/ethnicity, education, type of pay, industry, occupation (proxy for job risk), body mass index, and the interaction between sleep duration and work hours. Based on the inclusion criteria, there were an estimated 129,950,376 workers annually at risk and 3,634,446 work-related medically treated injury episodes (overall injury rate 2.80/100 workers). Unadjusted annualized injury rates/100 workers across weekly work hours were 2.03 (< or =20 h), 3.01 (20-30 h), 2.45 (31-40 h), 3.45 (40-50 h), 3.71 (50-60 h), and 4.34 (>60 h). With regards to self-reported daily sleep time, the estimated annualized injury rates/100 workers were 7.89 (<5 h sleep), 5.21 (5-5.9 h), 3.62 (6-6.9 h), 2.27 (7-7.9 h), 2.50 (8-8.9 h), 2.22 (9-9.9 h), and 4.72 (>10 h). After controlling for weekly work hours, and aforementioned covariates, significant increases in risk/1 h decrease were observed for several sleep categories. Using 7-7.9 h sleep as reference, the adjusted injury risk (odds ratio [OR] for a worker sleeping a total of <5 h/day was 2.65 (95% confidence interval [CI]: 1.57-4.47), for 5-5.9 h 1.79 (95% CI: 1.22-2.62), and for 6-6.9 h 1.40 (95% CI: 1.10-1.79). No other usual sleep duration categories were significantly different than the reference; however, for >10 h of usual daily sleep, the OR was marginally significantly elevated, 1.82 (95% CI: 0.96-3.47). These results suggest significant increases in work-related injury risk with decreasing usual daily self-reported sleep hours and increasing weekly work hours, independent of industry, occupation, type of pay, sex, age, education, and body mass.

The work-related burden of injury in a rapidly industrialising commune in Viet Nam.

BACKGROUND: Health and injury surveillance data of the highest achievable quality are needed in order to appropriately allocate scarce resources at the local and national levels. METHODS: This is the first reported surveillance study of injury using a complete community sample in Viet Nam. Workplaces in Xuan Tien Commune most likely to benefit from intervention were identified and ranked by the magnitude of the problem (or highest injury count), the risk (highest incidence rates) and the burden (the effect of injuries on the livelihoods of workers). RESULTS: 591 injuries occurring in the month prior to survey administration were recalled, which satisfied the injury case criteria of this study (the annualised incidence rate (IR) was 681 per 1000 residents). 482 were attributed to work activities (82%), yielding an annualised IR of 1001/1000 full time employee equivalents (FTE). The highest number of injuries occurred in the manufacturing sector (n=299), followed by agriculture with far fewer injuries (n=70). The highest rate of injury was in the transport, storage and communications sector (annualised IR 1583/1000 FTE), followed by manufacturing (1235/1000 FTE) and agriculture (844/1000 FTE). CONCLUSION: This study identified patterns of risk which, because data collection reflected work culture, are believed to be more reliable than those from previous studies. Interventions in the manufacture of machinery and equipment sector (the largest industry in the commune) would have the most impact in reducing occupational injuries. Despite the trend towards manufacturing, agriculture is still a high priority with a continuing substantial impact.