Martin Cherniack

Evaluation and management of chronic work-related musculoskeletal disorders of the distal upper extremity

This clinical review will describe the epidemiology, clinical presentation, and management of the following work-related musculoskeletal disorders (WMSDs) of the distal upper extremity: deQuervains disease, extensor and flexor forearm tendinitis/tendinosis, lateral and medial epicondylitis, cubital tunnel syndrome, and hand-arm vibration syndrome (HAVS). These conditions were selected for review either because they were among the most common WMSDs among patients attending the New York State Occupational Health Clinics (NYSOHC) network, or because there is strong evidence for work-relatedness in the clinical literature. Work-related carpal tunnel syndrome is discussed in an accompanying paper. In an attempt to provide evidence-based treatment recommendations, literature searches on the treatment of each condition were conducted via Medline for the years 1985-1999. There was a dearth of studies evaluating the efficacy of specific clinical treatments and ergonomic interventions for WMSDs. Therefore, many of the treatment recommendations presented here are based on a consensus of experienced public health-oriented occupational medicine physicians from the NYSOHC network after review of the pertinent literature. A summary table of the clinical features of the disorders is presented as a reference resource.

Review of the biodistribution and toxicity of the insect repellent N,N-diethyl-m-toluamide (DEET)

A review of the biodistribution and toxicity of the insect repellent N,N-diethyl-m-toluamide (DEET) is presented. Workers using repellent containing this compound may be exposed to greater than 442 g in 6 mo. In human studies, variable penetration into the skin of from 9 to 56% of a topically applied dose and absorption into the circulatory system of approximately 17% have been reported. Excretion of DEET by humans was initially rapid but not as complete as in animal models. Only about one-half of the absorbed DEET was excreted by humans over 5 d. Depot storage of DEET in the skin was also documented. Skin irritant effects, including scarring bullous dermatitis in humans, were reported. One animal study that reported embryotoxicity could not be confirmed by other investigators. The limited testing for mutagenicity and carcinogenicity provided negative results. Neurotoxic effects were observed in workers exposed to 4 g or more per week. Six young girls developed encephalopathies after exposure to unspecified amounts of DEET ranging from small to massive doses. Three of these girls later died. The cause of their death has not been resolved. Because of the lack of information, further research into the absorption, carcinogenicity, and neurotoxic effects is needed.

A Conceptual Framework for Integrating Workplace Health Promotion and Occupational Ergonomics Programs

Musculoskeletal, cardiovascular, and mental health are all associated with the physical and psychosocial conditions of work, as well as with individual health behaviors. An integrated approach to workplace health-promotion programs should include attention to the work environment, especially in light of recent findings that work organization influences so-called lifestyle or health behaviors. Macroergonomics provides a framework to improve both physical and organizational features of work and, in the process, to empower individual workers. The Center for the Promotion of Health in the New England Workplace (CPH-NEW) is a research-to-practice effort examining the effectiveness of worksite programs that combine occupational safety and health—especially /sc>ergonomics—with health promotion, emphasizing the contribution of work organization to both. Two intervention studies are underway in three different sectors: health care, corrections, and manufacturing. Each study features participatory structures to facilitate employee input into health goal-setting, program design and development, and evaluation, with the goal of enhanced effectiveness and longer-term sustainability.

Workplace health protection and promotion through participatory ergonomics: an integrated approach.

A multidisciplinary team of researchers at the Center for the Promotion of Health in the New England Workplace (CPH-NEW) developed an evidencebased approach to address three recognized challenges to workplace programs designed to improve employee health: establishing employee ownership, integrating with work organization, and sustainability. The two main innovations being introduced in combination were (1) integrating traditional workplace health protection (e.g., ergonomics, industrial hygiene) with health promotion (e.g., assisting workers in improving health behaviors) and (2) introducing a bottom-up participatory model for engaging employees in innovative iterative design efforts to enhance both components of this integrated program. In the program, which was modeled after participatory ergonomics programs, teams of workers engage in the iterative design of workplace interventions to address their prioritized health concerns with the support of a multilevel steering committee. The integrated approach being tested can complement existing worksite safety and health initiatives and promote organizational learning, with expected synergistic effects.

Statistical design and monitoring of the carotene and retinol efficacy trial (CARET)

CARET is a chemoprevention trial of beta-carotene and vitamin A with lung cancer as the primary outcome. Participants at high risk for lung cancer are drawn from two populations: asbestos-exposed workers and heavy smokers. The intervention is a daily combination of 30 mg beta-carotene and 25,000 IU vitamin A as retinyl palmitate. Nearly 18,000 participants will be followed for a mean 6 years, yielding over 100,000 person-years of follow-up. We project that this sample size will have 80% power to detect a 23% decrease in the incidence of lung cancer cases. The purpose of this paper is to present the values of the key sample size parameters of CARET; our schemes for monitoring CARET for sample size adequacy, incidence of side effects, and efficacy of the study vitamins; an overview of the data collected; and plans for the primary, secondary, and ancillary analyses to be performed at the end of the trial. These approaches to the design, monitoring, and analysis of CARET are applicable for many other prevention trials.

A cross sectional epidemiological survey of shipyard workers exposed to hand-arm vibration.

The hand-arm vibration syndrome, widely known as vibration white finger, is a disorder of nerves and blood vessels that occurs in workers exposed to segmental vibration. A cross sectional symptom survey was performed on a sample of workers employed by a large shipyard in the north eastern United States. Random samples were drawn from departments composed of full time dedicated pneumatic grinders, workers with part time exposure to vibration, and other workers not exposed to vibratory tools. Of the 375 workers sampled, 79% responded. The prevalence of white finger symptoms was 71%, 33%, and 6% among the three exposure groups respectively. Similarly, the prevalence of numbness and tingling in the hands and fingers in the three exposure groups was 84%, 50%, and 17%. Workers were classified according to the Stockholm Workshop staging systems for vascular and sensorineural symptom severity. Exposure-response analyses of both vascular and sensorineural stage showed monotonically increasing prevalence of higher disease stages with increasing duration of exposure. Logistic regression analysis, performed to control for potential confounding factors including age and current smoking state, produced highly significant (p less than 0.001) associations between cumulative duration of exposure and prevalence of symptoms. In these analyses smoking state was significantly related to vascular and sensorineural symptoms and age was not. Average latency to onset of symptoms was less than five years of full time equivalent work with vibratory tools. Logistic regression analyses were performed to assess the effect of use of particular work practices on reported symptoms. Further study of this workforce with objective, quantitative measures of peripheral neurological and vascular function is required to characterise the clinical and subclinical effects of vibration exposure.

Barriers to Implementation of Workplace Health Interventions: An Economic Perspective

Objective: To identify insurance related, structural, and workplace cultural barriers to the implementation of effective preventive and upstream clinical interventions in the working age adult population. Methods: Analysis of avoided costs from perspective of health economics theory and from empiric observations from large studies; presentation of data from our own cost-plus model on integrating health promotion and ergonomics. Results: We identify key avoided costs issues as a misalignment of interests between employers, insurers, service institutions, and government. Conceptual limitations of neoclassical economics are attributable to work culture and supply-driven nature of health care. Discussion: Effective valuation of avoided costs is a necessary condition for redirecting allocations and incentives. Key content for valuation models is discussed.

Vibration exposure, smoking, and vascular dysfunction

OBJECTIVES Vibration white finger (VWF), also known as “occupational Raynauds phenomenon”, is marked by arterial hyperresponsiveness and vasoconstriction during cold stimulation. The impact of tobacco use, and by extension stopping smoking, on the long term course of the disease has been inconclusively characterised. The objectives of this study included assessment of the impact of tobacco use on symptoms and on objective tests in shipyard workers exposed to vibration, and in gauging the natural history of the disorder after stopping exposure and changing smoking patterns. METHODS In a cross sectional investigation, 601 current and former users of pneumatic tools were evaluated subjectively for cold related vascular symptoms, and tested by cold challenge plethysmography. There was follow up and subsequent testing of 199 members of the severely effected subgroup of smokers and non-smokers, many of whom had stopped smoking in the interval between tests. Effects of smoking and stopping smoking on symptoms and plethsymographic results were assessed. RESULTS Symptoms and measured abnormal vascular responses related to cold were more severe in smokers than in non-smokers. Follow up of 199 severely effected members of the cohort, all removed from exposure for 2 years, indicated that smokers were almost twice as likely to have more severe vasospasm (test finger/control finger systolic blood pressure% (FSBP%) <30) than were non-smokers (−32.2% v 17.4%). 53 Subjects who stopped smoking during the interval between tests improved, and were indistinguishable from non-smokers similarly exposed to vibration. Additional physiological benefits of stopping smoking were still apparent at further follow up examination, 1 year later. Improvements evident on plethysmography were not accompanied by improvements in symptoms, which were unaffected by smoking. CONCLUSIONS Smoking seems to delay physiological improvement in response to cold challenge in workers with VWF, after the end of exposure to vibration. Symptoms were less likely to improve over time than digital blood pressure, and were less affected by smoking.

Depression and work family conflict among corrections officers.

Objective:This article assessed work-to-family conflict (W-FC) and family-to-work conflict (F-WC) and their impact on depression among corrections officers in two correctional facilities in the United States. Methods:The sample consisted of 220 officers who completed questionnaires that included data on demographics, sense of coherence (SOC), physical health, psychosocial job characteristics, and work–family conflict. The Center for Epidemiologic Studies Depression Scale (CES-D-10) assessed depression. Results:The mean CES-D score was 7.8 (SD = 5.2); 31% had scores of 10 or more, indicative of serious psychological distress. The SOC, W-FC, and F-WC were significantly and positively associated with depression; W-FC mediated the effects of SOC on depression. Psychosocial job characteristics were not related to depression. Conclusions:Depressive symptoms were high among officers, and W-FC was a critical factor contributing to psychological distress.

Talking About Health: Correction Employeesʼ Assessments of Obstacles to Healthy Living

Objective: Describe health risks/obstacles to health among correctional employees. Methods: Mixed-methods approach combined results from four focus groups, 10 interviews, 335 surveys, and 197 physical assessments. Results: Obesity levels were higher than national averages (40.7% overweight and 43.3% obese), with higher levels associated with job tenure, male gender, and working off-shift. Despite widespread concern about the lack of fitness, leisure exercise was higher than national norms. Respondents had higher levels of hypertension than national norms, with 31% of men and 25.8% of women hypertensive compared with 17.1% and 15.1% for national norms. Stress levels were elevated. Officers related their stress to concerns about security, administrative requirements, and work/family imbalance. High stress levels are reflected in elevated levels of hypertension. Conclusions: Correctional employees are at high risk for chronic disease, and environmental changes are needed to reduce risk factors.