Work disability prevention research: current and future prospects.

Work disability prevention has evolved from being a component of disease outcomes studies, to a separate and growing research discipline. In part, this is due to recognition that work outcomes often do not correlate with other health outcomes; the causes of work disability are multiple, complex, and often distinct from associated health conditions or treatments; and that work disability creates an important personal, economic and social burden that is often preventable. Conceptual frameworks, measures, research methods and interventions specific to this area have been developed, many have been validated across different contexts, and an international community of researchers and trainees in work disability prevention has formed. The articles included in this special section exemplify the breadth of current research in this field, and future opportunities for greater cross- disciplinary collaboration and translation of research to practical implementation and policy interventions.

Occupational physical demands and same-level falls resulting in fracture in female workers: an analysis of workers' compensation claims.

OBJECTIVES: To examine the association between occupational physical demands and risk of same-level falls resulting in fracture in female workers' compensation claimants. METHODS: From workers' compensation claims for same-level falls, 7286 female workers from three age groups (18-49, 50-59 and 60-79 years) were randomly selected. Levels of occupational physical activity, standing and sitting were assigned using occupational codes. Fracture occurrence was determined using the International Classification of Diseases codes. Risks of same-level falls resulting in fracture were compared by quartiles of physical activity, standing and sitting. RESULTS: In the 18-49-year age group, physical activity, standing and sitting at work were not significantly associated with risk of same-level falls resulting in fracture (p value trend: 0.07, 0.18 and 0.10, respectively). In the 50-59 and 60-79-year age groups, increasing duration of standing and decreasing duration of sitting were associated with decreasing risk of same-level falls resulting in fracture (p value trend: standing<0.001, 0.01; sitting<0.001, 0.02). In the 50-59-year age group, the relative risks of same-level falls resulting in fracture were 0.53, 0.41 and 0.82 for the second, third and highest quartiles of physical activity, respectively, as compared with workers in the lowest quartile (95% confidence interval 0.35 to 0.80, 0.23 to 0.72, 0.56 to 1.21, respectively). In the 60-79-year age group, there was a similar, but not significant, U-shaped association between occupational physical activity and risk of same-level falls resulting in fracture. CONCLUSION: Moderate occupational physical demands may be associated with a decreased risk of same-level fall resulting in fracture in female workers' compensation claimants>or=50 years of age.

Blurring the distinctions between on and off the job injuries: similarities and differences in circumstances.

OBJECTIVES: To compare the causes of non-fatal work and non-work injuries and the places or environments where they occur. It has been suggested that many injuries may have similar etiologies on and off the job and thus involve some common prevention strategies. However lack of comparable data on work relatedness has prevented testing this proposition. METHODS: The National Health Interview Survey (NHIS) now collects information on the cause, location, and work relatedness of all medically attended injuries. National US estimates of non-fatal work and non-work injuries were compared by cause and place/location for working age adults (18-64 years). RESULTS: Overall 28.6% of injuries to working age adults were work related (37.5% among employed people). The causes and locations of many work and non-work injuries were similar. Falls, overexertion, and struck/caught by were leading causes for work and non-work injuries. Motor vehicle injuries were less likely to be work related (3.4% at work v 19.5% non-work) and overexertion injuries more likely to be work related (27.1% v 13.8%). Assaults were less than 1% of work injuries and 1.8% of non-work injuries. Both work and non-work injuries occurred in every location examined-including the home where 3.5% of injuries were work related. CONCLUSIONS: Work and non-work injuries share many similarities suggesting opportunities to broaden injury prevention programs commonly restricted to one setting or the other. Comprehensive efforts to prevent both non-work and work injuries may result in considerable cost savings not only to society but also directly to employers, who incur much of the associated costs.

Performance decrements resulting from illness in the workplace: the effect of headaches.

OBJECTIVES: Studies on the impact of illness on work productivity are important to rationally allocate healthcare resources and to design programs to mitigate these effects. This investigation was conducted to develop and apply daily measures of illness episodes, and to collect subjective and objective data on work performance impacts. Medical bill reviewers completed daily responses to a questionnaire about headache manifestations, severity, and speed of work using interactive voice response (IVR). Of 134 eligible enrolled subjects, 117 (86%) provided at least 30 daily reports over 3 months. Their responses were matched to difficulty-adjusted objective measures: daily output, time on the system, and productivity. Respondents were clinically classified as migraineurs (n = 56), other headache disorders (n = 47), or having no headache disorder (n = 14). Each headache episode was classified as a migraine or nonmigraine headache based on reported manifestations. RESULTS: The three groups were similar in a variety of demographic factors, and mean subject-specific measures of speed, output, and productivity. In a multivariate model using general estimating equations, only episode severity (not type of headache or person-specific diagnosis) was found to be associated with a significant decrement in speed or productivity. The self-reported decrement in speed (approximately 20%) was much greater than the actual measured effect on productivity (approximately 8%). Intensive daily diary collection by IVR on symptoms and work performance is feasible. However, analysis of detailed daily objective productivity data can be complex, with significant unmeasured sources of variance. Severity may be a more important determinant of headache effect on work performance than specific diagnosis. Future studies on illness episodes and work performance should measure informal accommodations that may enable employees to compensate for episodic illnesses.

Rethinking quality in the context of persons with disability.

OBJECTIVE: To review the current health services literature related to quality of care for persons with disabilities and to highlight the need for a unique framework for conceptualizing quality and patient safety issues for this population. DESIGN: Drawing on quality measurement theory, we formulate a multi-dimensional model of quality of care for persons with disability. This model is then used to identify and summarize findings from existing health services research that relate to the quality, of care for persons with disability. STUDY SELECTION: We searched MEDLINE and other databases for primary research and review articles containing the phrases 'quality of care', 'patient safety', 'access', 'patient experience', and 'coordination of care' in conjunction with the words 'disability' or 'impairment'. RESULTS: A review of health services research suggests several potential issues in the areas of clinical quality, access, client experience, and coordination. Physical barriers, transportation, communication difficulties, and client and provider attitudes present barriers to receiving appropriate client-centered care. Communication difficulties between provider and client may increase risk for accidental injury and decrease the quality of the client experience. Frequent contact with the health care system and the complexity of an individual's situation also increase the risk of accidental injury. Coordination, the 'lubricant' that facilitates links for all areas of quality for a person with disability, presents the most significant opportunity for improvement, because multiple medical and social providers are typically involved in the care of individuals with disabling conditions. CONCLUSION: Health care providers need to embrace a multi-disciplinary approach to quality to meet the needs of persons with disabilities. Funders and purchasers need to provide flexibility in funding to enable a comprehensive primary care approach, while health service researchers need to adopt a broad view of quality to capture issues of importance for persons with disabilities.

Flock worker's lung: broadening the spectrum of clinicopathology, narrowing the spectrum of suspected etiologies.

STUDY OBJECTIVES: Workers in the nylon flocking industry recently have been found to be at increased risk of chronic nongranulomatous interstitial lung disease. Although a spectrum of cytologic and histopathologic abnormalities has been observed, nonspecific interstitial pneumonia, lymphoid nodules, and lymphocytic bronchiolitis predominated in the 19 previously reported cases of flock worker's lung. Here we describe five additional patients who appear to expand the histopathologic spectrum and add to the evidence suggesting a causative role for respirable-sized nylon fragments. METHODS: We studied all North American patients (n = 5) found in 1998 to satisfy our previous case definition of flock worker's lung. Two pulmonary pathologists independently reviewed each biopsy specimen. RESULTS: All five patients reported cough and dyspnea. Only one patient had crackles on chest auscultation. High-resolution CT scan, interpreted with attention to subtle ground-glass attenuation, remained a highly sensitive diagnostic test. Pulmonary function tests and plain chest radiograph were less sensitive. One patient's wedge biopsy showed previously described prototypical findings. Two others had transbronchial biopsies showing some of the same features. The fourth patient's wedge biopsy showed desquamative interstitial pneumonia. The fifth patient had bilateral synchronous adenocarcinoma but with radiographic evidence of diffuse interstitial fibrosis. These 5 patients and the 19 patients studied previously were exposed to nylon flock manufactured by a rarely used cutting technology. CONCLUSION: Findings in these five patients appear to broaden the spectrum of the clinicopathology of flock worker's lung and add to the evidence incriminating respirable-sized nylon particulates produced during the manufacture and use of rotary-cut nylon flock.

Nylon flock-associated interstitial lung disease.

A work-related interstitial lung disease has been diagnosed in workers at five nylon flock facilities in three different states and a Canadian province. The National Institute for Occupational Safety and Health hosted a workshop at which consulting pulmonary pathologists reviewed lung tissue samples from all the cases for which lung biopsy material was available (15 of 20 cases known in January 1998). After independent review and scoring of these lung tissue specimens, the pathologists reached consensus that the histopathological findings revealed a characteristic lesion-a lymphocytic bronchiolitis and peribronchiolitis with lymphoid hyperplasia represented by lymphoid aggregates. The pathologists noted that the pathological findings were distinctive when compared with known lung conditions. The clinical presentation for the cases generally included cough, dyspnea, restrictive ventilatory defect with reduction in diffusing capacity, and interstitial markings on chest radiographs or high-resolution computed tomography (HRCT) scans. Six of the cases improved after removal from workplace exposure without medical treatment. Six others, who had recovered with medical treatment and removal from the workplace, had relapses in both symptoms and objective findings after attempting to return to nylon flock work. With this and other evidence supporting the existence of chronic interstitial pneumonitis associated with nylon flock processing, workshop participants recommended surveillance for early identification of affected workers and their removal from further workplace exposure.

Work-related upper-extremity disorders and work disability: clinical and psychosocial presentation.

Work-related upper-extremity disorders (WRUEDs) are an increasingly common cause of work-related symptoms and disability. Although most upper-extremity disorders are acute and self-limited, a small percentage of workers with symptoms go on to permanent disability and account for the majority of costs associated with these conditions. Little is known, however, about this progression from symptoms to disability and how it might be prevented. In this study, we evaluate the demographic, vocational, medical, and psychosocial characteristics of patients with WRUEDs and examine several hypotheses regarding the differences between working and work-disabled patients. One hundred twenty-four consecutive patients were evaluated in a clinic specializing in occupational upper-extremity disorders. Patients currently working (n = 55) and work-disabled patients (n = 59) were similar with regard to age, gender, and reported job demands. The work-disabled group reported less time on the job, more surgeries, a higher frequency of acute antecedent trauma, and more commonly had "indeterminate" musculoskeletal diagnoses. They also reported higher pain levels, more anger with their employer, and a greater psychological response or reactivity to pain. These findings, though cross-sectional in nature, suggest that, in addition to medical management, more aggressive approaches to pain control, prevention of unnecessary surgery, directed efforts to improve patients' abilities to manage residual pain and distress, and attention to employer-employee conflicts may be important in preventing the development of prolonged work disability in this population.

The relative importance of dispositional optimism and control appraisals in quality of life after coronary artery bypass surgery.

Similar mechanisms have been proposed to explain the stress-buffering effects of both dispositional optimism and perceived control. Yet dispositional optimism as a personal resource should function independently of situational control appraisals. To evaluate the unique and additive contributions to adaptation of control appraisals and optimism, we followed 49 individuals scheduled for coronary artery bypass surgery. One month before surgery dispositional optimism was associated with neither health locus of control nor specific expectancies about the outcomes of surgery. Dispositional optimism, however, was associated with perceived control over the course of the illness and with quality of life appraisals. Although presurgery optimism predicted life quality 8 months after surgery, this was not the case when general and specific control appraisals and specific expectancies were included in the prediction. These findings are discussed as they relate to current conceptions of trait optimism.

Decision-making in worker fitness and risk evaluation.

The information needed to determine fitness or risk and to make employment recommendations and decisions is reviewed. Four key questions are discussed: What are the risks and demands of a specific job? Is the worker capable of performing the job? Would the job place the worker at increased risk? What should the clinician do when there is a likelihood of increased risk or decreased capabilities?

Neurologic considerations in worker fitness evaluation.

This chapter focuses on neurological conditions that may seriously change work performance or risk, as well as considerations in neurological evaluation of the asymptomatic worker.