Using job-title-based physical exposures from O*NET in an epidemiological study of carpal tunnel syndrome

OBJECTIVE: We studied associations between job title based measures of force and repetition and incident carpal tunnel syndrome (CTS). BACKGROUND: Job exposure matrices (JEMs) are not commonly used in studies of work-related upper extremity disorders. METHODS: We enrolled newly-hired workers into a prospective cohort study. We assigned a Standard Occupational Classification (SOC) code to each job held and extracted physical work exposure variables from the Occupational Information Network (O*NET). CTS case definition required both characteristic symptoms and abnormal median nerve conduction. RESULTS: 751 (67.8%) of 1107 workers completed follow-up evaluations. 31 subjects (4.4%) developed CTS during an average of 3.3 years of follow-up. Repetitive Motion, Static Strength, and Dynamic Strength from the most recent job held were all significant predictors of CTS when included individually as physical exposures in models adjusting for age, gender, and BMI. Similar results were found using time-weighted exposure across all jobs held during the study. Repetitive Motion, Static Strength, and Dynamic Strength were correlated, precluding meaningful analysis of their independent effects. CONCLUSION: This study found strong relationships between workplace physical exposures assessed via a JEM and CTS, after adjusting for age, gender, and BMI. Though job title based exposures are likely to result in significant exposure misclassification, they can be useful for large population studies where more precise exposure data are not available. APPLICATION: JEMs can be used as a measure of workplace physical exposures for some studies of musculoskeletal disorders

Modeling the cost–benefit of nerve conduction studies in pre-employment screening for carpal tunnel syndrome

OBJECTIVES: To evaluate the costs associated with pre-employment nerve conduction testing as a screening tool for carpal tunnel syndrome (CTS) in the workplace. METHODS: We used a Markov decision analysis model to compare the costs associated with a strategy of screening all prospective employees for CTS and not hiring those with abnormal nerve conduction, versus a strategy of no screening for CTS. The variables included in our model included employee turnover rate, the incidence of CTS, the prevalence of median nerve conduction abnormalities, the relative risk of developing CTS conferred by abnormal NCS, the costs of pre-employment screening, and the workers' compensation costs to the employer for a case of CTS. RESULTS: In our base case, total employer costs for CTS from the perspective of the employer (cost of screening plus costs for workers' compensation associated with CTS) were higher when screening was used. Median costs per employee position over five years were $503 for the screening strategy vs.$200 for a strategy of no screening. Sensitivity analysis showed that a strategy of screening was cost-beneficial from the perspective of the employer only under a few circumstances. In Monte Carlo simulation varying all parameters, we found a 30% probability that screening would be cost-beneficial. CONCLUSIONS: A strategy of pre-employment screening for CTS should be carefully evaluated for yield and social consequences before being implemented. Our model suggests such screening is not appropriate for most employers

Use of mechanical patient lifts decreased musculoskeletal symptoms and injuries among health care workers

Objective: To evaluate the effectiveness of mechanical patient lifts in reducing musculoskeletal symptoms, injuries, lost workday injuries, and workers' compensation costs in workers at a community hospital. Design: Pre-post intervention study. Setting: Three nursing units of a small community hospital. Patients or subjects: Nursing personnel. Interventions: Mechanical patient lifts were made available and nursing staff trained in their use between August 2000 and January 2001. Main outcome measures: Workers completed symptom surveys at baseline and six months after lift training. Pre-intervention and post-intervention rates of injuries and lost workday injuries using Occupational Safety and Health Administration logs of the three study units, from the period July 1999 through March 2003 were analyzed. Injuries potentially related to lifting patients were included in the analyses. Using workers' compensation data from the same time period, the compensation paid ($per full time equivalent [FTE]) due to injuries during the pre-intervention and post-intervention period was calculated. Results: Sixty one staff members were surveyed pre-intervention; 36 (59$484 per FTE pre-intervention and $151 per FTE post-intervention. Conclusion: Reductions were observed in injury rates, lost workday injury rates, workers' compensation costs, and musculoskeletal symptoms after deployment of mechanical patient lifts. Strengths of this study include the community hospital setting and the inclusion of a variety of different outcomes. Limitations include the pre-post study design and the small sample size

The effect of exposure to long working hours on stroke: A systematic review and meta-analysis from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury

BACKGROUND: The World Health Organization (WHO) and the International Labour Organization (ILO) are developing joint estimates of the work-related burden of disease and injury (WHO/ILO Joint Estimates), with contributions from a large network of individual experts. Evidence from mechanistic data and prior studies suggests that exposure to long working hours may cause stroke. In this paper, we present a systematic review and meta-analysis of parameters for estimating the number of deaths and disability-adjusted life years from stroke that are attributable to exposure to long working hours, for the development of the WHO/ILO Joint Estimates. OBJECTIVES: We aimed to systematically review and meta-analyse estimates of the effect of exposure to long working hours (three categories: 41-48, 49-54 and ≥55 h/week), compared with exposure to standard working hours (35-40 h/week), on stroke (three outcomes: prevalence, incidence, and mortality). DATA SOURCES: A protocol was developed and published, applying the Navigation Guide to systematic reviews as an organizing framework where feasible. We searched electronic databases for potentially relevant records from published and unpublished studies, including Ovid MEDLINE, PubMed, EMBASE, Scopus, Web of Science, CISDOC, PsycINFO, and WHO ICTRP. We also searched grey literature databases, Internet search engines, and organizational websites; hand-searched reference lists of previous systematic reviews; and consulted additional experts. STUDY ELIGIBILITY AND CRITERIA: We included working-age (≥15 years) individuals in the formal and informal economy in any WHO and/or ILO Member State but excluded children (aged \u3c 15 years) and unpaid domestic workers. We included randomized controlled trials, cohort studies, case-control studies and other non-randomized intervention studies with an estimate of the effect of exposure to long working hours (41-48, 49-54 and ≥55 h/week), compared with exposure to standard working hours (35-40 h/week), on stroke (prevalence, incidence or mortality). STUDY APPRAISAL AND SYNTHESIS METHODS: At least two review authors independently screened titles and abstracts against the eligibility criteria at a first review stage and full texts of potentially eligible records at a second stage, followed by extraction of data from qualifying studies. Missing data were requested from principal study authors. We combined relative risks using random-effects meta-analysis. Two or more review authors assessed the risk of bias, quality of evidence and strength of evidence, using the Navigation Guide and GRADE tools and approaches adapted to this project. RESULTS: Twenty-two studies (20 cohort studies, 2 case-control studies) met the inclusion criteria, comprising a total of 839,680 participants (364,616 females) in eight countries from three WHO regions (Americas, Europe, and Western Pacific). The exposure was measured using self-reports in all studies, and the outcome was assessed with administrative health records (13 studies), self-reported physician diagnosis (7 studies), direct diagnosis by a physician (1 study) or during a medical interview (1 study). The outcome was defined as an incident non-fatal stroke event in nine studies (7 cohort studies, 2 case-control studies), incident fatal stroke event in one cohort study and incident non-fatal or fatal ( mixed ) event in 12 studies (all cohort studies). Cohort studies were judged to have a relatively low risk of bias; therefore, we prioritized evidence from these studies, but synthesised evidence from case-control studies as supporting evidence. For the bodies of evidence for both outcomes with any eligible studies (i.e. stroke incidence and mortality), we did not have serious concerns for risk of bias (at least for the cohort studies). Eligible studies were found on the effects of long working hours on stroke incidence and mortality, but not prevalence. Compared with working 35-40 h/week, we were uncertain about the effect on incidence of stroke due to working 41-48 h/week (relative risk (RR) 1.04, 95% confidence interval (CI) 0.94-1.14, 18 studies, 277,202 participants, I CONCLUSIONS: We judged the existing bodies of evidence for human evidence as inadequate evidence for harmfulness for all exposure categories for stroke prevalence and mortality and for exposure to 41-48 h/week for stroke incidence. Evidence on exposure to 48-54 h/week and ≥55 h/week was judged as limited evidence for harmfulness and sufficient evidence for harmfulness for stroke incidence, respectively. Producing estimates for the burden of stroke attributable to exposures to working 48-54 and ≥55 h/week appears evidence-based, and the pooled effect estimates presented in this systematic review could be used as input data for the WHO/ILO Joint Estimates. PROTOCOL IDENTIFIER: https://doi.org/10.1016/j.envint.2018.06.016. PROSPERO REGISTRATION NUMBER: CRD42017060124