Household Water Lead and Hematologic Toxic Effects in Chronic Kidney Disease.

Importance: The consequences of low levels of environmental lead exposure, as found commonly in US household water, have not been established. Objective: To examine whether commonly encountered levels of lead in household water are associated with hematologic toxicity among individuals with advanced kidney disease, a group known to have disproportionate susceptibility to environmental toxicants. Design, Setting, and Participants: Cross-sectional analysis of household water lead concentrations and hematologic outcomes was performed among patients beginning dialysis at a Fresenius Medical Care outpatient facility between January 1, 2017, and December 20, 2021. Data analysis was performed from April 1 to August 15, 2023. Exposure: Concentrations of lead in household water were examined in categorical proportions of the Environmental Protection Agency's allowable threshold (15 µg/L) and continuously. Main Outcomes and Measures: Hematologic toxic effects were defined by monthly erythropoiesis-stimulating agent (ESA) dosing during the first 90 days of incident kidney failure care and examined as 3 primary outcomes: a proportion receiving maximum or higher dosing, continuously, and by a resistance index that normalized to body weight and hemoglobin concentrations. Secondarily, hemoglobin concentrations for patients with data prior to kidney failure onset were examined, overall and among those with concurrent iron deficiency, thought to increase gastrointestinal absorption of ingested lead. Results: Among 6404 patients with incident kidney failure (male, 4182 [65%]; mean [SD] age, 57 [14] years) followed up for the first 90 days of dialysis therapy, 12% (n = 742) had measurable lead in household drinking water. A higher category of household lead contamination was associated with 15% (odds ratio [OR], 1.15 [95% CI, 1.04-1.27]) higher risk of maximum monthly ESA dosing, 4.5 (95% CI, 0.8-8.2) µg higher monthly ESA dose, and a 0.48% (95% CI, 0.002%-0.96%) higher monthly resistance index. Among patients with pre-kidney failure hemoglobin measures (n = 2648), a higher household lead categorization was associated with a 0.12 (95% CI, -0.23 to -0.002) g/dL lower hemoglobin concentration, particularly among those with concurrent iron deficiency (multiplicative interaction, P = .07), among whom hemoglobin concentrations were 0.25 (95% CI, -0.47 to -0.04) g/dL lower. Conclusion: The findings of this study suggest that levels of lead found commonly in US drinking water may be associated with lead poisoning among susceptible individuals.

Transmission of SARS-CoV-2 considering shared chairs in outpatient dialysis: a real-world case-control study.

BACKGROUND: SARS-CoV-2 can remain transiently viable on surfaces. We examined if use of shared chairs in outpatient hemodialysis associates with a risk for indirect patient-to-patient transmission of SARS-CoV-2. METHODS: We used data from adults treated at 2,600 hemodialysis facilities in United States between February 1st and June 8th, 2020. We performed a retrospective case-control study matching each SARS-CoV-2 positive patient (case) to a non-SARS-CoV-2 patient (control) treated in the same dialysis shift. Cases and controls were matched on age, sex, race, facility, shift date, and treatment count. For each case-control pair, we traced backward 14 days to assess possible prior exposure from a 'shedding' SARS-CoV-2 positive patient who sat in the same chair immediately before the case or control. Conditional logistic regression models tested whether chair exposure after a shedding SARS-CoV-2 positive patient conferred a higher risk of SARS-CoV-2 infection to the immediate subsequent patient. RESULTS: Among 170,234 hemodialysis patients, 4,782 (2.8 %) tested positive for SARS-CoV-2 (mean age 64 years, 44 % female). Most facilities (68.5 %) had 0 to 1 positive SARS-CoV-2 patient. We matched 2,379 SARS-CoV-2 positive cases to 2,379 non-SARS-CoV-2 controls; 1.30 % (95 %CI 0.90 %, 1.87 %) of cases and 1.39 % (95 %CI 0.97 %, 1.97 %) of controls were exposed to a chair previously sat in by a shedding SARS-CoV-2 patient. Transmission risk among cases was not significantly different from controls (OR = 0.94; 95 %CI 0.57 to 1.54; p = 0.80). Results remained consistent in adjusted and sensitivity analyses. CONCLUSIONS: The risk of indirect patient-to-patient transmission of SARS-CoV-2 infection from dialysis chairs appears to be low.

Transmission of SARS-CoV-2 Considering Shared Chairs in Outpatient Dialysis: A Real-World Case-Control Study.

BACKGROUND: SARS-CoV-2 is primarily transmitted through aerosolized droplets; however, the virus can remain transiently viable on surfaces. OBJECTIVE: We examined transmission within hemodialysis facilities, with a specific focus on the possibility of indirect patient-to-patient transmission through shared dialysis chairs. DESIGN: We used real-world data from hemodialysis patients treated between February 1 st and June 8 th , 2020 to perform a case-control study matching each SARS-CoV-2 positive patient (case) to a non-SARS-CoV-2 patient (control) in the same dialysis shift and traced back 14 days to capture possible exposure from chairs sat in by SARS-CoV-2 patients. Cases and controls were matched on age, sex, race, facility, shift date, and treatment count. SETTING: 2,600 hemodialysis facilities in the United States. PATIENTS: Adult (age ≥18 years) hemodialysis patients. MEASUREMENTS: Conditional logistic regression models tested whether chair exposure after a positive patient conferred a higher risk of SARS-CoV-2 infection to the immediate subsequent patient. RESULTS: Among 170,234 hemodialysis patients, 4,782 (2.8%) tested positive for SARS-CoV-2 (mean age 64 years, 44% female). Most facilities (68.5%) had 0 to 1 positive SARS-CoV-2 patient. We matched 2,379 SARS-CoV-2 positive cases to 2,379 non-SARS-CoV-2 controls; 1.30% (95%CI 0.90%, 1.87%) of cases and 1.39% (95%CI 0.97%, 1.97%) of controls were exposed to a chair previously sat in by a shedding SARS-CoV-2 patient. Transmission risk among cases was not significantly different from controls (OR=0.94; 95%CI 0.57 to 1.54; p=0.80). Results remained consistent in adjusted and sensitivity analyses. LIMITATION: Analysis used real-world data that could contain errors and only considered vertical transmission associated with shared use of dialysis chairs by symptomatic patients. CONCLUSIONS: The risk of indirect patient-to-patient transmission of SARS-CoV-2 infection from dialysis chairs appears to be low. PRIMARY FUNDING SOURCE: Fresenius Medical Care North America; National Institute of Diabetes and Digestive and Kidney Diseases (R01DK130067).

The time of onset of intradialytic hypotension during a hemodialysis session associates with clinical parameters and mortality.

Intradialytic hypotension (IDH) is a common complication of hemodialysis, but there is no data about the time of onset during treatment. Here we describe the incidence of IDH throughout hemodialysis and associations of time of hypotension with clinical parameters and survival by analyzing data from 21 dialysis clinics in the United States to include 785682 treatments from 4348 patients. IDH was defined as a systolic blood pressure of 90 mmHg or under while IDH incidence was calculated in 30-minute intervals throughout the hemodialysis session. Associations of time of IDH with clinical and treatment parameters were explored using logistic regression and with survival using Cox-regression. Sensitivity analysis considered further IDH definitions. IDH occurred in 12% of sessions at a median time interval of 120-149 minutes. There was no notable change in IDH incidence across hemodialysis intervals (range: 2.6-3.2 episodes per 100 session-intervals). Relative blood volume and ultrafiltration volume did not notably associate with IDH in the first 90 minutes but did thereafter. Associations between central venous but not arterial oxygen saturation and IDH were present throughout hemodialysis. Patients prone to IDH early as compared to late in a session had worse survival. Sensitivity analyses suggested IDH definition affects time of onset but other analyses were comparable. Thus, our study highlights the incidence of IDH during the early part of hemodialysis which, when compared to later episodes, associates with clinical parameters and mortality.

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.

Expectations for Return to Work After Workplace Injuries: The Relationship Between Estimated Time to Return to Work and Estimate Accuracy.

Purpose Worker's expectations for return to working have been found to relate to return-to-work (RTW) outcomes; however, it is unclear if this varies depending upon the expected time to RTW. To advance the understanding of the relationship between expectations and RTW, we set out to answer the following research questions: Are shorter estimated times to RTW more accurate than estimates that are longer of duration? In addition, we sought to determine if there was a point in time that coincides with RTW estimates no longer being reliably related to time to RTW. Methods We utilized workers' compensation data from a large, United States-based insurance company. Injured workers' (N = 15,221) expectations for returning to work were compared with the termination of their total temporary indemnity payments. A linear regression model was used to determine if shorter lengths of expected time to RTW were more accurate. Quantile regression modelling was used to determine if there was point at which the expected time to RTW no longer reliably relates to the actual time to RTW. Results Findings indicated a positive relationship such that as the number of expected days to RTW increased, the number of days of difference (estimate error) between the actual time to RTW and the expected time to RTW also increased (ß = 0.34, P < .001). The results of the quantile regression modelling indicated that for all quantiles estimated, with the exception of the quantile for estimates of 360 days, the relationship between the actual time to RTW and the expected time to RTW were statistically significant (P < .05). However, for RTW estimates of more than 14 days the relationship began decreasing in strength. Conclusion Results indicate that injured workers' expectations for RTW can be used for RTW forecasting purposes. However, it is the case that RTW events in the near future can be forecasted with higher accuracy than those that are more distant, and that in general, injured workers will underestimate how long it will take them to RTW.

Updating the "Risk Index": A systematic review and meta-analysis of occupational injuries and work schedule characteristics.

Fatigue is a major risk factor for occupational 'accidents' and injuries, and involves dimensions of physical, mental, and muscular fatigue. These dimensions are largely influenced by temporal aspects of work schedules. The "Risk Index" combines four fatigue-related components of work schedules to estimate occupational 'accident' and injury risk based on empirical trends: shift type (morning, afternoon/evening, night), length and consecutive number, and on-shift rest breaks. Since its first introduction in 2004, several additional studies have been published that allow the opportunity to improve the internal and external validity of the "Risk Index". Thus, we updated the model's estimates by systematically reviewing the literature and synthesizing study results using meta-analysis. Cochrane Collaboration directives and MOOSE guidelines were followed. We conducted systematic literature searches on each model component in Medline. An inverse variance approach to meta-analysis was used to synthesize study effect sizes and estimate between-studies variance ('heterogeneity'). Meta-regression models were conducted to explain the heterogeneity using several effect modifiers, including the sample age and sex ratio. Among 3,183 initially identified abstracts, after screening by two independent raters (95-98% agreement), 29 high-quality studies were included in the meta-analysis. The following trends were observed: Shift type. Compared to morning shifts, injury risk significantly increased on night shifts (RR = 1.36 [95%CI = 1.15-1.60], n = 14 studies), while risk was slightly elevated on afternoon/evening shifts, although non-significantly (RR = 1.12 [0.76-1.64], n = 9 studies). Meta-regressions revealed worker's age as a significant effect modifier: adolescent workers (≤ 20 y) showed a decreased risk on the afternoon/evening shift compared to both morning shifts and adult workers (p < 0.05). Number of consecutive shifts. Compared to the first shift in a block of consecutive shifts, risk increased exponentially for morning shifts (e.g., 4th: RR = 1.09 [0.90-1.32]; n = 6 studies) and night shifts (e.g., 4th: RR = 1.36 [1.14-1.62]; n = 8 studies), while risk on afternoon/evening shifts appeared unsystematic. Shift length. Injury risk rose substantially beyond the 9th hour on duty, a trend that was mirrored when looking at shift lengths (e.g., >12 h: RR = 1.34 [1.04-1.51], n = 3 studies). Rest breaks. Risk decreased for any rest break duration (e.g., 31-60 min: RR = 0.35 [0.29-0.43], n = 2 studies). With regards to time between breaks, risk increased with every additional half hour spent on the work task compared to the first 30 min (e.g., 90-119 min: RR = 1.62 [1.00-2.62], n = 3 studies). Rest break duration and interval seem to interact such that with increasing duration, the time between breaks becomes irrelevant. The updated "Risk Index". All four components were combined to form the updated model and the relative risk values estimated for a variety of work schedules. The resulting "Risk Map" shows regions of highest risk when rest breaks are not taken frequently enough (i.e. <4 h) or are too short (i.e. <30 min), when shift length exceeds 11 h, and when work takes place during the night (particularly for >3 consecutive night shifts). The "Risk Index" is proposed as an empirical model to predict occupational 'accident' and injury risk based on the most recent data in the field, and can serve as a tool to evaluate hazards and maximize safety across different work schedules.

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.

The Relationship Between Work-Disability Duration and Claimant's Expected Time to Return to Work as Recorded by Workers' Compensation Claims Managers.

Purpose This research sought to determine whether there is a relationship between claimants' expected time to return to work (RTW) as recorded by claims managers and compensated days of work disability. Methods We utilized workers' compensation data from a large, United States-based insurance company. RTW expectations were collected within 30 days of the claim being reported and these were compared with the termination of total temporary indemnity payments. Bivariate and hierarchical regression analyses were conducted. Results A significant relationship between expected time to RTW and compensated disability duration was observed. The unadjusted correlation between work-disability duration and expected time to RTW was .25 (p < .001). Our multivariate model explained 29.8 % of the variance, with expected time to RTW explaining an additional 9.5 % of the variance in work-disability duration beyond what was explained by the covariates. Conclusion The current study's findings support the hypothesis that claimant RTW estimates as recorded by claims managers are significantly related to compensated-disability duration, and the relationship is maintained after controlling for variance that can be explained by other variables available within workers' compensation databases.

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.