The intervention research process in occupational safety and health: an overview from the National Occupational Research Agenda Intervention Effectiveness Research team.

The goal of occupational safety and health intervention effectiveness research is to determine whether specific interventions work to prevent work-related injury and illness. But that is not the whole story. It is also important that the development and implementation of the intervention be evaluated. All three phases (development, implementation, and effectiveness) are central to a model of intervention research proposed by the National Occupational Research Agenda Intervention Effectiveness Research team. Areas for future research are also presented.

Psychological variables in hypertension: relationship to casual or ambulatory blood pressure in men.

OBJECTIVE: The evidence linking hypertension with personality or psychological characteristics, such as anger, anxiety, or depression, remains equivocal. This may be due in part to limitations of personality theory, confounding by awareness of hypertension, and/or inherent difficulties in measuring blood pressure. This study was designed to investigate the association between mild hypertension as defined by both ambulatory and casual (clinic) blood pressure measurements and various measures of personality and psychological characteristics. METHODS: We examined this association in a population-based sample of 283 men between the ages of 30 and 60 years from eight work sites in New York City, using an ambulatory blood pressure monitor and controlling for age, race/ethnicity, and body mass index. RESULTS: We found no consistent difference between participants with mild hypertension and those with normal blood pressure on any of the psychological variables assessed, including Type A behavior pattern, state and trait anger, anger expression, anxiety, symptoms of psychological distress, locus of control, or attributional style. Results were not due to the use of antihypertensive medication by some of the participants with hypertension nor to the dichotomization of blood pressure into those with and without mild hypertension. This contrasts with previous findings from this study showing a sizable association of ambulatory blood pressure and hypertension with job strain (a situational measure), age, and body mass index. CONCLUSIONS: These null results suggest that situational, biological, and perhaps behavioral factors are the primary determinants of mild hypertension and that the predictive significance of psychological or dispositional factors is low or negligible in those without overt cardiovascular disease.

The workplace and cardiovascular health: conclusions and thoughts for a future agenda.

The evidence in this book provides convergent validation of a causal relationship between workplace stressors and CVD. Here, the editors explore new strategies for enhanced prevention and clinical management, work place interventions, and social policy to reduce the impact of CVD. These strategies acquire an urgent public health dimension, given the magnitude of the CVD epidemic and the current deterioration in conditions of working life.

Why the workplace and cardiovascular disease?

Cardiovascular disease (CVD) remains the major cause of morbidity and mortality in the industrialized world. Current approaches to managing the CVD epidemic are based on powerful engineering models and advanced medical techniques. Innovative research has identified a number of risk factors for hypertension and CVD. However, our understanding of these disorders and our ability to manage the epidemic remain limited. A social epidemiologic paradigm suggests that essential hypertension and CVD are diseases of industrialized society of rather recent historical origins. To better understand and manage the CVD epidemic, current models need to incorporate a heretofore relatively neglected realm of social life in the workplace.

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: deQuervain's 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.

Clinical experience and results of a Sentinel Health Investigation related to indoor fungal exposure.

This is a review of exposure conditions, clinical presentation, and morbidity of children and adults with indoor fungal exposure such as toxic Stachybotrys chartarum. Indoor exposure was characterized using different methods including microscopic, culture, cytotoxicity screening tests, and chemical analyses. Clinical case histories and physical and laboratory findings are presented of children (age < 18 years, n = 22; mean age 9 years; 60% females) and adults (age >18 years, n = 125; mean age 39 years, 67% females) who consulted an environmental health specialty clinic. In the pediatric patients' exposure history, widespread fungal contamination of water-damaged building materials with known toxic or allergic fungi was identified. Primarily disorders of the respiratory system, skin, mucous membranes, and central nervous system were reported. Some enumeration and functional laboratory abnormalities, mainly of the lymphatic blood cells, were observed, although no statistically significant differences were found. IgE or IgG fungi-specific antibodies, used as exposure markers, were positive in less than 25% of all tested cases. In an evaluation of a symptomatic girl 11 years of age (sentinel case investigation) living in an apartment with verified toxigenic fungi (i.e., S. chartarum), several health indicators showed improvement after exposure cessation.

The impact of lean production and related new systems of work organization on worker health.

New systems of work organization, such as lean production and total quality management, have been introduced by employers throughout the industrialized world to improve productivity, quality, and profitability. However, few studies have examined the impact of such systems on occupational injuries or illnesses or on job characteristics related to job strain, which has been linked to hypertension and cardiovascular disease. The studies reviewed provide little evidence to support the hypothesis that lean production "empowers" auto workers. In fact, auto industry studies suggest that lean production creates intensified work pace and demands. Increases in decision authority and skill levels are modest or temporary, whereas decision latitude typically remains low. Thus, such work can be considered to have job strain. In jobs with ergonomic stressors, intensification of labor appears to lead to increases in musculoskeletal disorders. The evidence for adverse health effects remains inconclusive for related new work systems in other industries, such as modular manufacturing or patient-focused care.

A longitudinal study of job strain and ambulatory blood pressure: results from a three-year follow-up.

OBJECTIVE: This study was conducted to investigate the hypothesis that exposure to "job strain" is related to increased ambulatory blood pressure (ABP). METHOD: Participants were 195 men who wore an ABP monitor for 24 hours on two occasions 3 years apart. Job strain status, evaluated at each assessment, was used to identify four groups: those not having job strain at either assessment (N = 138), those having job strain at both times (N = 15), and two crossover groups. Regression analysis was used to examine the cross-sectional associations of ABP with job strain, controlling for other known risk factors. Repeated-measures analysis of variance was used to examine the association of ABP change with the category of job strain change. RESULTS: The cross-sectional analysis of the Time 2 data yielded almost identical, highly significant effects of job strain on ABP as was shown in our previously published Time 1 analysis. Those in high strain jobs at both times had systolic/diastolic ABPs at work and at home that were, on average, 11/7 mm Hg higher than those with no job strain at both times; the crossover groups had intermediate levels of ABP. The longitudinal analysis showed that those with a high strain job at Time 1, but not at Time 2, had a significant decrease in work and home ABP of approximately 5/3 mm Hg. CONCLUSIONS: The previously reported cross-sectional association between job strain and ABP was replicated at follow-up. The group repeatedly exposed to job strain had higher levels of ABP at Time 2 than either crossover group. Furthermore, change in job strain status partially predicted change in ABP. These results provide new evidence supporting the hypothesis that job strain is an occupational risk factor in the etiology of essential hypertension.

Job strain and health behaviors: results of a prospective study.

PURPOSE: To assess the association between job demands, job decision latitude, and job strain (defined by Karasek as a combination of high demands and low decision latitude) and cardiovascular disease-related health behaviors such as cigarette smoking, alcohol use, lack of exercise, and overweight. DESIGN: Cross-sectional and prospective. SETTING: Nine New York City public and private sector worksites. SUBJECTS: Two hundred eighty-five male employees, aged 30 to 60, in a wide variety of white-collar and blue-collar job titles. MEASURES: Medical examinations and surveys, which included demographic, health behavior, and job characteristics data. RESULTS: Prospectively, among 189 men, increase in job decision latitude over 3 years was associated with decrease in cigarette smoking, by analysis of covariance, controlling for age, race, education, marital status, and number of children at home (F (8, 180) = 4.37, p = .005). The largest increase in latitude occurred among the 13 men who quit smoking. However, change in job characteristics was not associated with change in overweight or alcohol use. Cross-sectional analyses did not produce consistent associations. CONCLUSIONS: The effectiveness of smoking cessation may be aided by modification of structural features of the work environment, such as job decision latitude. This study is limited by the small number of subjects who were engaged in high risk behaviors.

Environmental influences on blood pressure and the role of job strain.

OBJECTIVE: To review the evidence that human essential hypertension is at least in part the result of the influence of psychosocial factors, with special reference to occupational stress (job strain). FINDINGS: The prevalence of human hypertension is related to social factors such as urbanization and education. Several studies, conducted both experimentally in animals and observationally in people, have suggested that chronic social conflict is associated with higher blood pressure. Ambulatory monitoring has shown that most people have their highest pressures during working hours. Occupational stress can be evaluated as job strain, which is a combination of high demands at work with low decision latitude or control. Job strain has been related to coronary heart disease, and a number of studies have shown that it is also associated with higher ambulatory blood pressures, both cross-sectionally and prospectively, in men but not in women. Men in high strain jobs also show an increased left ventricular mass. Laboratory studies of blood pressure reactivity to stressful tasks support the concept of loss of control being associated with higher pressures. CONCLUSIONS: Job strain is a risk factor for hypertension in men, but not in women.

Psychosocial work stress and pregnancy-induced hypertension.

We examined the association between work during pregnancy and pregnancy-induced hypertension in a prospective cohort study of 717 women. We classified cases, whom we identified by uniform review of blood pressures and proteinuria in prenatal records, into two categories: gestational hypertension (N = 16, 2.5%) and preeclampsia (N = 11, 1.7%). All cases of pregnancy-induced hypertension occurred among the 575 subjects who worked during the first trimester of pregnancy. The association with employment was not explained by primiparity or other known risk factors, or by physical work demands, long work hours, or total hours of paid work, housework, and child care. Stressful job characteristics, however, did show associations with pregnancy-induced hypertension. In particular, gestational hypertension was associated with low decision latitude and low job complexity among women in lower-status jobs [standardized odds ratio (SOR) = 2.4 for low latitude, 95% confidence interval (CI) = 1.1-5.2; SOR = 2.1 for low complexity, 95% CI = 1.0-4.6]. Among women in higher-status jobs, gestational hypertension was associated with job pressures/low control (SOR = 3.6, 95% CI = 0.9-15.1). Psychosocial job stressors, not studied previously, might explain earlier reports of a raised risk of pregnancy-induced hypertension among pregnant workers.