Work-related asthma in cobalt-exposed workers.

OBJECTIVE: Workers exposed to cobalt may develop two lung conditions, asthma or lung fibrosis. There is a relative lack of awareness of the risk of lung disease from cobalt exposure. METHODS: The state of Michigan requires physicians, and hospitals to report work-related asthma (WRA). A standardized telephone interview of each reported case was conducted. An industrial hygienist evaluated the reported cases's workplace, and a physician reviewed the results to confirm the diagnosis. This is a population-based case series of all workers in whom the exposure to cobalt was confirmed as likely responsible for WRA from 1988 to 2017. We also included an illustrative case report and data on the workplace evaluations. RESULTS: Of the 35 cases identified, 77% were males, 97.1% were white, and 62.9% had a history of smoking cigarettes. Fifteen (44%) cases were involved in manufacturing cutting tools and machine tool accessories. Symptoms improved in 28 cases (80%) when away from work. Fourteen cases (40%) had emergency department visits, while 10 (28.6%) had been hospitalized for breathing problems. Spirometry had been performed for 33 (94.3%) cases. Only 13 (37.1%) reported they were informed by a doctor that their asthma was work-related. Twenty-six inspections were conducted at 21 different workplaces, where 498 coworkers were interviewed, 55 (11%) of which had respiratory symptoms at work. Six workplaces were cited for cobalt air level higher than permissible limits. These inspections resulted in $29,380 in penalties. CONCLUSIONS: WRA secondary to cobalt is associated with significant morbidity. Most of the cases were unaware of their medical diagnosis.

HLA class II DPB1 and DRB1 polymorphisms associated with genetic susceptibility to beryllium toxicity.

OBJECTIVES: Chronic beryllium disease (CBD) is a hypersensitivity granulomatous pulmonary disease caused by exposure to the metal beryllium (Be²âº). Our objective was to extend current knowledge of the genetics of beryllium disease by examining all HLA-DPB1 and HLA-DPR1 gene polymorphisms and the interactions between them. METHODS: DNA-based typing of HLA-DPB1 and HLA-DRB1 loci at the allele level was performed on 65 CBD, 44 beryllium sensitised (BeS) but without CBD and 288 non-affected, beryllium exposed controls. RESULTS: The DPßE69 residue regardless of zygosity, but particularly if present on non-*0201 alleles, was of primary importance for the development of CBD and BeS, while other negatively charged residues DPßDE55, 56 and DPßDE84, 85 incrementally increased, although not independently, the risk. The DPßE69 positive alleles with charge -7 or -9 were associated with both CBD and BeS. The polymorphic residues DPßE69, DPßDE55, 56 and DPßDE84, 85 were responsible for the -9 charge and the first two residues for the -7 charge. CONCLUSIONS: In the absence of DPßE69, DRßE71 is a risk factor for CBD and BeS. DPßE69 and DRßE71 are adjacent to other amino acids that are also negatively charged, suggesting that the positively charged Be²âº modifies the local environment of the epitopes in a way that promotes interactions between peptides and T cells and results in CBD. Finally, the protective effect of the DPB1*0201 positive haplotype may involve particular polymorphisms outside of the DPB1 gene.

Hypersensitivity pneumonitis and antigen identification--An alternate approach.

OBJECTIVES: Identification of the causal antigen for patients with hypersensitivity pneumonitis (HP) is challenging in a standard clinical setting. The purpose of this pilot study was to determine whether it was possible to evaluate the home/workplace of patients, and identify the causal antigen. METHODS: Using a case-control study design we compared the presence of antibody to antigen collected in the environment of individuals with HP and controls consisting of family members/co-workers. Based on patient interviews, homes/workplaces were evaluated and suspected sources of antigen collected for use in immunoassays. RESULTS: Nineteen individuals with HP participated with 15 classified as having fibrotic disease. Up to 54 bulk samples were collected from each patient's environment, with multiple isolates (antigens) cultured from each. Of the seven individuals who tested positive to one or more environmental samples, three had a positive response to more than 1 antigen from the environmental sample (range 1-9). Twelve individuals tested positive to antigen(s) on a standard panel, with only one overlapping with the antigen from the home/workplace sample. A significant association existed between results of interviews/site evaluations, and ability to collect antigen eliciting a positive response (p < 0.001). CONCLUSION: Antigen identification was successful for patients with 'active' disease. Antigens for which patients test positive on standard panels may not be present in their environment. One benefit to patient-centered testing is the ability to develop recommendations specific to their environment. As most individuals tested positive for >1 antigen, further investigation is warranted to determine the actual antigen responsible for disease.

Web based listing of agents associated with new onset work-related asthma.

BACKGROUND: Work-related asthma is common and yet remains a challenge to diagnose. Access to a listing of agents associated with work-related asthma has been suggested as useful in assisting in the diagnosis. METHODS: The Association of Occupational and Environmental Clinics (AOEC) developed criteria that were used to review the peer-reviewed medical literature published in English. Based on this review, substances were designated either as a sensitizing agent or an irritant. The reviews were conducted by a board certified internist/pulmonologist/occupational medicine specialist from 2002 to 2007 and a board certified internist/occupational medicine physician from 2008- date. All reviews were then reviewed by the nine member AOEC board of directors. RESULTS: The original list of agents associated with new onset work-related asthma was derived from the tables of a text book on work-related asthma. After 13 years of review, there are 327 substances designated as asthma agents on the AOEC list; 173 (52.9%) coded as sensitizers, 35 (10.7%) as generally recognized as an asthma causing agent, four (1.2%) as irritants, two (0.6%) as both a sensitizer and an irritant and 113(34.6%) agents that still need to be reviewed. CONCLUSIONS: The AOEC has developed a readily available web based listing of agents associated with new onset work-related asthma in adults. The listing is based on peer-reviewed criteria. The listing is updated twice a year. Regular review of the peer-reviewed medical literature is conducted to determine whether new substances should be added to the list. Clinicians should find the list useful when considering the diagnosis of work-related asthma.

Increased urinary enzyme excretion in workers exposed to nephrotoxic chemicals.

Nephrotoxic chemicals are commonly present in the environment, particularly in the workplace. The level of occupational exposure to these chemicals has been so reduced that exposure to these agents now rarely causes clinically evident acute renal disease. A sensitive indicator of renal injury, urinary excretion of N-acetyl-beta-glucosaminidase, was utilized to evaluate persons exposed in the workplace to lead, mercury, or organic solvents, for evidence of renal effects from this exposure. None of the persons had clinically evident renal disease by history, none had hypertension, and all had normal findings on urinalysis. When compared with appropriate control populations, workers exposed to lead, workers exposed to mercury, and two of three groups of workers exposed to organic solvents had significant increases in urinary acetyl glucosaminidase activity. The third group of laboratory workers with low exposure to organic solvents had no increase in urinary acetyl glucosaminidase activity. It is concluded that exposure to environmental nephrotoxins at levels currently considered safe can produce renal effects as manifested by elevations of urinary acetyl glucosaminidase excretion. It is speculated that these renal effects are not always innocuous.

Carcinoembryonic antigen (CEA) plasma levels in Michigan and Wisconsin dairy farmers.

Carcionogenic embryonic antigen (CEA) titers were determined for 611 Michigan farmers exposed to PBB and a control nonexposed population of 139 Wisconsin farmers. The overall prevalence of elevated CEA titers was slightly higher in the Michigan study group, but the difference was not statistically significant. Smoking and/or significant past or present conditions (inflammatory bowel disease, ulcers, polyps, liver disease, chronic lung disease, or malignancies) were found to result in higher prevalence of elevated CEA titers, in both the Michigan study group and the Wisconsin control group, thus confirming previous reports. In addition, serum PBB concentrations appeared to be positively correlated with CEA titers. The possibility that the effect of PBB concentrations appeared to be positively correlated with CEA titers. The possibility that the effect of PBB may be additive to that of other factors which are known to result in an increased prevalence of elevated CEA titers is discussed.

Unanticipated prevalence of symptoms among dairy farmers in Michigan and Wisconsin.

Adverse human health effects resulting from exposure to polychlorinated biphenyls (PBBs) were unknown until the accidental contamination of Michigan dairy farm animal feed in 1973-1974. Human exposure resulted from the consumption of contaminated meat, milk, dairy products, and eggs. In November 1976, the Environmental Sciences Laboratory conducted comprehensive examinations of 933 farmers and residents in Mighigan who were likely to have consumed farm products contaminated with PBB. A comparison group of 229 Wisconsin dairy farmers were examined in March 1977 and the same scientific and medical staffs that conducted the Michigan survey were responsible and the same procedures used. A complete history of symptomatology by organ system, including year of first onset, duration, frequency, and severity of each symptom was obtained by a physician on all adults examined. Statistical analysis of the prevalence of symptoms at the time of examination or during the preceding year in the Michigan and Wisconsin populations studied found the Michigan group to have a significantly higher prevalence of skin, neurological and musculoskeletal symptoms. The increase was seen among the younger age groups 16-35 and 36-55. Michigan females had a higher prevalence of neurological symptoms than the Michigan males. The existing differences could not be explained without considering an etiologic role for exposure to PBB.

Occurrence of occupational asthma.

To estimate the percentage of adult asthmatics with occupational asthma in Michigan, a sample of 94 patients, aged 20 to 65 years, who were discharged from one of three Michigan hospitals in 1990 with the primary diagnosis of asthma were interviewed. The patients were classified using the National Institute for Occupational Safety and Health (NIOSH) criteria as having either probable occupational asthma, possible occupational asthma, or not having occupational asthma. Three percent of the adult asthmatics interviewed met the criteria for having probable occupational asthma. One patient from each hospital had probable occupational asthma. Fifteen of 60 patients (25 percent) from hospital A, 3 of 25 patients (12 percent) from hospital B, and 2 of the 9 patients (22 percent) from hospital C had probable or possible occupational asthma. After adjusting for the difference in response rate among patients from the three hospitals, the percentage of adult asthmatics in Michigan whose asthma is caused by work exposure is estimated to be between 3 percent and 20.2 percent. In contrast, 25.5 percent of the patients stated their asthma was caused by bad working conditions. If these percentages were generalizable to the whole state, then according to our survey 330 to 2,222 or by self-reports of the patients, 2,800 of the 11,000 hospital discharges per year in Michigan for asthma among adults could be attributed to a work exposure.

Occupational asthma in a beet sugar processing plant.

A patient with occupational asthma in the beet sugar processing industry is described. Symptomatology, skin testing, immunologic testing, and specific bronchoprovocation testing indicate exposure to moldy sugar beet pulp was the cause of the patient's occupational asthma. Cooperation between the treating physician and public health authorities is encouraged.

Silicosis in the 1990s.

OBJECTIVE: To describe state-based surveillance for silicosis that estimates prevalence of this condition, describes characteristics of affected individuals, and targets public health interventions. DESIGN: The data presented are a case series of patients with silicosis reported to a state health department. Patients were interviewed using a standardized questionnaire, chest radiographs interpreted by a "B-reader," pulmonary function tests obtained from medical records, and follow-back investigations conducted at the worksites where the cases had been exposed to silica. SETTING: All individuals with silicosis in the state of Michigan reported to the Michigan Department of Public Health (MDPH). SUBJECTS: Individuals included in this article were reported from 1987 through 1995. Cases were reported by hospitals, physicians, the state workers' compensation bureau, or from death certificates. Only data on individuals who met the criteria for silicosis developed by the National Institute for Occupational Safety and Health (NIOSH) are included. RESULTS: Between 1987 and 1995, 577 people were reported to MDPH who met the NIOSH criteria for silicosis. About 60% of the reports came from hospitals. The disease is occurring mainly among men born before 1940 who began working in a Michigan ferrous foundry in the 1930s or 1940s and worked there > 20 years. Over 40% of the patients are black. The overall annual average incidence rate of silicosis among black men (14.3 cases per 100,000) is seven times higher than among white men (2.1 cases per 100,000). The individuals identified with silicosis generally have severe disease. Almost 30% have progressive massive fibrosis and another 31.7% have advanced simple silicosis. Only about a third of all patients have normal results of breathing tests. Thirteen percent had been told they had tuberculosis (includes both clinical disease and a positive skin test). They have an increase of over 300% in the likelihood of dying of nonmalignant respiratory disease, both restrictive and obstructive, and an 80% increase in the likelihood of dying of lung cancer. Despite the severity of disease, over 45% of the individuals had not applied for workers' compensation. Although silicosis typically occurs after a long duration of exposure to silica, some individuals developed silicosis after a relatively short time. Three people developed silicosis who began working with silica in the 1980s, 18 in the 1970s, and 66 in the 1960s. Initial industrial hygiene follow-up inspections where the individuals had worked showed ongoing exposure above recommended and/or legal levels. Repeated inspections to these same facilities have subsequently shown reductions in silica exposure. CONCLUSION: This state-based surveillance system has proved useful in characterizing individuals with silicosis, estimating its prevalence, increasing the medical community's awareness of the condition, and targeting effective public health interventions.

The ocular manifestations and functional effects of occupational argyrosis.

Thirty employees of an industrial plant involved in the manufacture of silver nitrate and silver oxide underwent ophthalmologic evaluation in an effort to evaluate the frequency and extent of ocular argyrosis. The most frequently noted ocular abnormality was pigmentation of the conjunctiva, present in 20 workers; corneal pigmentation occurred in 15 workers. A direct relationship existed between the levels of pigmentation and duration of employment. Ocular pigmentation was seen more frequently than cutaneous pigmentation. Ten workers noted decreased night vision, but electrophysiologic and psychophysiologic studies of seven of these ten workers demonstrated no functional deficits.

Age-related hepatitis B seroconversion rates in health care workers.

BACKGROUND: Protective hepatitis titers are reported for more than 90% of healthy adults who received three intradeltoid injections of vaccine. Some factors that influence seroconversion rates include age, sex, and presence of chronic diseases. METHODS: Because of work-related factors that placed them at risk of acquiring hepatitis B, 112 employees, who ranged in age from 20 to 70 years with a mean age of 39.2 years, completed the hepatitis B vaccination series between 1986 and 1993. All participants received three vaccinations. RESULTS: Hepatitis B surface antibody did not develop in 16 of 112 recipients (14.2%, 95% CI, 7.6% to 20.8%). Race, sex, and duration to antibody titer did not affect rates of seroconversion. Age greater than 50 years was associated with significantly decreased seroconversion rates (64.7%, 95% CI, 42.0% to 87.4%) compared with seroconversion rates of those younger than 50 years of age (89.5%, 95% CI 83.3% to 95.7%, p = 0.02). CONCLUSIONS: Our results indicate that when a hepatitis B immunization program is implemented, seroconversion rates are lower than published rates for healthy adults and adolescents. We recommend that seroconversion data from immunization programs for employees at risk for hepatitis B be reviewed and that postimmunization testing be considered to ensure adequate protection for those employees at highest risk for nonconversion.

Use of skin-cancer prevention strategies among farmers and their spouses.

Epidemiologic studies show that farmers are at increased risk of skin cancer, presumed to be secondary to the increased time they spend outdoors with exposure to the sun. We surveyed a random sample of farmers and their spouses 40 years of age or older from four rural counties in Michigan on their knowledge, attitudes, and behavior regarding protection of their skin from the sun and screening medical exams for skin cancer. Questionnaires were completed by 1,342 farmers and their spouses. This was a response rate of 63.5%. Eighty to ninety percent knew the changes in the skin that could indicate cancer and required medical follow-up. Only 40% of the men and 65% of the women were likely to protect their skin when they went outdoors. Increasing age and personal history of skin cancer increased the likelihood of both men and women protecting their skin when they went outside. Additionally, higher-income women were likely to use sun protection. Despite the fact that 90% of the respondents had had a physical examination in the last three years, less than one third reported ever having had their skin examined for cancer. Increasing age, income, and education increased the likelihood of having had such an exam. The majority of those who had had a skin exam had the exam for a particular skin problem, and not as part of a routine physical examination. Farmers and their spouses need to increase their use of sun protection when going outside. Additionally, health care providers need to routinely include examination of the skin for skin cancer and alert their patients that it is being performed.

Spermatogenesis in men exposed to polybrominated biphenyl (PBB).

Experience with other halogenated hydrocarbons, animal experiments, and individual complaints indicated that polybrominated biphenyl (PBB) might have an effect on human spermatogenesis. Analysis of semen from 52 PBB-exposed men as compared with analysis of semen from a control group of 52 men not exposed to PBB revealed no differences in the distribution of sperm counts, motility, or morphology.

Environmentally related disorders of the cardiovascular system.

The patient's level of activity is typically the only work-related concern considered in clinical medicine. This article discusses why it is important for clinicians to expand their concern to include the possibility of exposure to various gases, metals, and chemicals when evaluating a patient with cardiovascular disease. Both at the time of diagnosis and when deciding whether a patient can return to work, the workplace exposures need to be reviewed for their potential to exacerbate or cause cardiac symptoms or even death. An appropriate exposure history with confirmatory laboratory tests will allow the clinician to diagnose and manage environmentally related cardiovascular disease.

A descriptive study of work aggravated asthma.

BACKGROUND AND AIMS: Work related asthma (WRA) is one of the most frequently reported occupational lung diseases in a number of industrialised countries. A better understanding of work aggravated asthma (WAA), as well as work related new onset asthma (NOA), is needed to aid in prevention efforts. METHODS: WAA and NOA in the United States were compared using cases reported to the National Institute for Occupational Safety and Health (NIOSH) from four state Sentinel Event Notification Systems for Occupational Risks (SENSOR) surveillance programmes for 1993-95. RESULTS: A total of 210 WAA cases and 891 NOA cases were reported. WAA cases reported mineral and inorganic dusts as the most common exposure agent, as opposed to NOA cases, in which diisocyanates were reported most frequently. A similar percentage of WAA and NOA cases still experienced breathing problems at the time of the interview or had visited a hospital or emergency room for work related breathing problems. NOA cases were twice as likely to have applied for workers' compensation compared with WAA cases. However, among those who had applied for worker compensation, approximately three-fourths of both WAA and NOA cases had received awards. The services and manufacturing industrial categories together accounted for the majority of both WAA (62%) and NOA (75%) cases. The risk of WAA, measured by average annual rate, was clearly the highest in the public administration (14.2 cases/10(5)) industrial category, while the risk of NOA was increased in both the manufacturing (3.2 cases/10(5)) and public administration (2.9 cases/10(5)) categories. CONCLUSIONS: WAA cases reported many of the same adverse consequences as NOA cases. Certain industries were identified as potential targets for prevention efforts based on either the number of cases or the risk of WAA and NOA.

A state-based surveillance system for work-related asthma.

The current national surveillance system for occupational illnesses underestimates the incidence of work-related asthma. This article describes a state-based surveillance system for work-related asthma. The Michigan surveillance system enables us to estimate the incidence of work-related asthma, describe the characteristics of affected individuals, and facilitate public health interventions in the form of workplace inspections. The data presented are based on interviews with a case-series of individuals with work-related asthma reported to the Michigan Department of Public Health (MDPH) from 1988 to 1994. We also present cross-sectional data on coworkers of the index cases, who were interviewed during the workplace investigations, and exposure measurements from those investigations. Potential cases were reported by physicians, hospitals, or the Michigan Department of Labor. Case eligibility was based on the criteria for work-related asthma developed by the National Institute for Occupational Safety and Health (NIOSH). Between 1988 and 1994, 725 people who met the NIOSH criteria for work-related asthma were reported to the MDPH. Seventy-six percent of the reports were from physicians, 17.1% were from hospitals, 7.3% were from workers' compensation records, and 3.5% were from other health professionals. Eighty-three percent of the reports were for individuals with the onset of newly diagnosed asthma after a period of symptomless exposure, 7.3% were for aggravation of preexisting asthma, and 9.5% were for reactive airway dysfunction syndrome (RADS). The overall annual average incidence rate of work-related asthma in Michigan was 2.9 cases per 100,000 workers. Rates were 0.8/100,000 in the service industry and 8.5/100,000 in manufacturing. Isocyanates and machining coolants were the two most common causes of asthma among workers reported to the surveillance system. Demographics of the individuals reported are described. During workplace follow-up investigations, 861 fellow workers were identified as having possible work-related asthma. Another 151 coworkers were identified from the company-maintained injury and illness logs as having possible work-related asthma. In addition, the investigations identified two new causes of work-related asthma. The primary limitations of the surveillance system include a lack of objective testing to confirm the diagnosis of work-related asthma and underreporting of cases. Despite these limitations, this state-based surveillance system has proven successful in identifying new cause of asthma and identifying workplaces with a high prevalence of workers with respiratory symptoms who may benefit from public health interventions.

Occupational noise-induced hearing loss surveillance in Michigan.

Occupational noise-induced hearing loss (NIHL) is an important yet often overlooked illness that can affect an individual's safety and performance at work. This article describes a state-based surveillance system for occupational NIHL. The Michigan surveillance system enables us to describe the magnitude of occupational NIHL among Michigan workers and direct public health interventions in the form of enforcement workplace inspections. The data presented are based on interviews of individuals with occupational NIHL reported to the Michigan Department of Consumer and Industry Services (MDCIS) by Michigan's audiologists and otolaryngologists from 1992-1997. From 1992-1997, 1378 individuals with occupational NIHL were reported to the MDCIS and interviewed about their exposures to noise at work. Over 70% of the workplace noise exposure were in manufacturing. At the most recent company where these individuals were exposed to noise, approximately 46% were not provided regular hearing testing. Regular hearing testing was more likely to occur in the larger companies and in industries covered by regulations requiring such testing to be performed. There were improvements over time in the percentages of companies providing regular hearing testing and hearing protection. Construction workers are employees among a group of industries that are not adequately protected from excessive noise exposures by occupational regulations. Regular hearing testing was not provided for over 90% of construction jobs, although hearing protection such as earplugs or earmuffs was provided for approximately half of these jobs. Forty-three state enforcement inspections were conducted at the companies reported by the patients interviewed, because these companies were reported to provide no regular hearing testing or no hearing protection despite exposures to excessive levels of noise. During the 43 inspections, 23 companies had noise levels above dBA, and 17 of those had either no hearing conservation program (HCP) or had one that was cited as being incomplete. The inspections potentially protected 758 similarly exposed workers in the companies with the high noise levels that lacked an HCP or that had a deficient HCP. The number of patients with occupational NIHL is likely a gross underestimate of the true magnitude of the disease. However, the surveillance system has identified workplaces with hazardous levels of noise and no HCP, thereby protecting similarly exposed coworkers of the index patients from further exposures to noise and hearing loss.

What percentage of workers with work-related illnesses receive workers' compensation benefits?

This study estimates the rate at which workers suffering from occupational illnesses file for workers' compensation lost wage benefits and identifies some of the factors that affect the probability that a worker with an occupational illness will file. A database of reports of known or suspected cases of occupational illness is matched with workers' compensation claims data. Overall, between 9% and 45% of reported workers file for benefits. Data limitations prevent a more precise estimate of this rate, but a large proportion of workers with occupational illnesses clearly does not utilize the worker's compensation system. Logit analysis of a choice-based sample shows that women and employees of small firms are more likely than others to file for worker's compensation and that filing rates vary considerably across industries and diagnostic categories. Acute conditions related to the current job are no more likely to lead to claims than chronic conditions with long latency periods between exposure and development of disease.

Why most workers with occupational repetitive trauma do not file for workers' compensation.

Despite the availability of no fault insurance for wage replacement and medical care costs, the majority of workers diagnosed with an occupational disease do not apply for workers' compensation. The objective of the study was to determine the reasons why workers diagnosed with work-related musculoskeletal disease did not apply for workers' compensation benefits. A cross-sectional study of 1598 individuals diagnosed with neck, upper extremity, and low back work-related musculoskeletal disease from April to June 1996 was performed. All individuals were interviewed over the telephone using a standardized questionnaire. The questionnaire included questions about the precipitating event; demographics; health limitations; mood; pain level; and attitudes toward their health care provider, fellow workers, management, work environment, and filing for workers' compensation. Whenever possible, standardized questions from previous surveys were used. The interviewed individuals with work-related musculoskeletal disease were reported by health care practitioners as required by the state of Michigan's occupational disease reporting law. Workers reported during 12 weeks in the spring of 1996 by a Michigan health care professional as having a neck, back, or upper extremity musculoskeletal disorder were eligible to participate. Among the 2703 reports received, 490 individuals could not be reached, 22 did not speak English, 12 had died or were too incapacitated by other medical conditions, and 581 refused. We interviewed 59% of all eligible workers and 73% of all workers who were reachable and capable of responding in English. Only 25% of workers diagnosed with musculoskeletal disease filed a workers' compensation claim. The factors significantly associated with filing a claim were (1) increased length of employment (> 21 years: odds ratio [OR], 3.01, 95% confidence interval [CI], 1.31 to 6.90); 11 to 20 years: OR, 2.34, 95% CI, 1.01 to 5.47; 6 to 10 years: OR, 1.76, 95% CI, 0.73 to 4.25; 1 to 5 years: OR, 2.36, 95% CI, 1.03 to 5.42; < 1 year: OR, 1.00; (2) lower annual income (< $40,000: OR, 1.75, 95% CI, 1.06 to 2.88 vs > or = $80,000: OR, 1.00); (3) workers' dissatisfaction with coworkers (OR, 1.76, 95% CI, 1.01 to 3.06); (4) physician restrictions on activity (OR, 2.16, 95% CI, 1.55 to 3.00); (5) type of physician providing treatment (specialist, including surgeon or orthopedist: OR, 3.63, 95% CI, 2.37 to 5.55); physical and occupational therapist: OR, 2.15, 95% CI, 1.35 to 3.43); family practitioner: OR, 1.33, 95% CI = 0.89 to 2.01; company physician: OR = 1.00); (6) off work > or = 7 days (OR, 14.85, 95% CI, 10.57 to 20.85); (7) decreased current health status (OR, 0.82, 95% CI, 0.70 to 0.96); and (8) increased severity of illness (OR, 1.24, 95% CI, 1.06 to 20.88). This study showed that only 25% of workers with a work-related musculoskeletal condition filed for workers' compensation and refutes the common perception that an individual with a work-related problem is likely to file a workers' compensation claim. The strongest predictors of who would file were those factors associated with the severity of the condition. Other factors were increasing length of employment, lower annual income, and worker dissatisfaction with coworkers. Our study population consisted mainly of unionized autoworkers, and our findings may not be generalizable to the total workforce.