Work organization, job insecurity, and occupational health disparities.

BACKGROUND: Changes in employment conditions in the global economy over the past 30 years have led to increased job insecurity and other work organization hazards. These hazards may play a role in creating and sustaining occupational health disparities by socioeconomic position, gender, race, ethnicity, and immigration status. METHODS: A conceptual model was developed to guide the review of 103 relevant articles or chapters on the role of work organization and occupational health disparities identified through a comprehensive search conducted by NIOSH. A second review was conducted of employment and workplace policies and programs designed to reduce the health and safety risks due to job insecurity and other work organization hazards. RESULTS: There is consistent evidence that workers in lower socioeconomic or social class positions are exposed to greater job insecurity and other work organization hazards than workers in higher socioeconomic positions. Likewise, racial and ethnic minorities and immigrants are exposed to greater job insecurity. Limited research examining the effects of interventions targeting work organization hazards on disparities has been conducted; nonetheless, intervention strategies are available and evidence suggests they are effective. CONCLUSIONS: Job insecurity and work organization hazards play a role in creating and sustaining occupational health disparities. Employment and workplace policies and programs have the potential to reduce these hazards, and to reduce disparities.

Job strain and ambulatory blood pressure: a meta-analysis and systematic review.

We reviewed evidence of the relationship between job strain and ambulatory blood pressure (ABP) in 29 studies (1985-2012). We conducted a quantitative meta-analysis on 22 cross-sectional studies of a single exposure to job strain. We systematically reviewed 1 case-control study, 3 studies of cumulative exposure to job strain, and 3 longitudinal studies. Single exposure to job strain in cross-sectional studies was associated with higher work systolic and diastolic ABP. Associations were stronger in men than women and in studies of broad-based populations than those with limited occupational variance. Biases toward the null were common, suggesting that our summary results underestimated the true association. Job strain is a risk factor for blood pressure elevation. Workplace surveillance programs are needed to assess the prevalence of job strain and high ABP and to facilitate workplace cardiovascular risk reduction interventions.

Current employment status, occupational category, occupational hazard exposure and job stress in relation to telomere length: the Multiethnic Study of Atherosclerosis (MESA).

OBJECTIVE: Telomere length has been proposed as a biomarker of cell senescence, which is associated with a wide array of adverse health outcomes. While work is a major determinant of health, few studies have investigated the association of telomere length with various dimensions of occupation. Accelerated cellular aging could be a common pathway linking occupational exposure to several health outcomes. METHODS: Leukocyte telomere length was assessed using quantitative PCR in a community-based sample of 981 individuals (age: 45-84 years). Questionnaires were used to collect information on current employment status, current or main occupation before retirement and job strain. The Occupational Resource Network (O*NET) database was linked to the questionnaire data to create five exposure measures: physical activity on the job, physical hazard exposure, interpersonal stressors, job control and job demands. Linear regression was used to estimate associations of occupational characteristics with telomere lengths after adjustment for age, sex, race, socioeconomic position and several behavioural risk factors. RESULTS: There were no mean differences in telomere lengths across current employment status, occupational category, job strain categories or levels of most O*NET exposure measures. There was also no evidence that being in lower status occupational categories or being exposed to higher levels of adverse physical or psychosocial exposures accelerated the association between age and telomere shortening. CONCLUSIONS: Cellular aging as reflected by shorter telomeres does not appear to be an important pathway linking occupation to various health outcomes.

Disability rates for cardiovascular and psychological disorders among autoworkers by job category, facility type, and facility overtime hours.

BACKGROUND: We examined the association between long work hours, assembly line work and stress-related diseases utilizing objective health and employment data from an employer's administrative databases. METHODS: A North American automobile manufacturing company provided data for claims for sickness, accident and disability insurance (work absence of at least 4 days) for cardiovascular disease (CVD), hypertension and psychological disorders, employee demographics, and facility hours worked per year for 1996-2001. Age-adjusted claim rates and age-adjusted rate ratios were calculated using Poisson regression, except for comparisons between production and skilled trades workers owing to lack of age denominator data by job category. Associations between overtime hours and claim rates by facility were examined by Poisson regression and multi-level Poisson regression. RESULTS: Claims for hypertension, coronary heart disease, CVD, and psychological disorders were associated with facility overtime hours. We estimate that a facility with 10 more overtime hours per week than another facility would have 4.36 more claims for psychological disorders, 2.33 more claims for CVD, and 3.29 more claims for hypertension per 1,000 employees per year. Assembly plants had the highest rates of claims for most conditions. Production workers tended to have higher rates of claims than skilled trades workers. CONCLUSIONS: Data from an auto manufacturer's administrative databases suggest that autoworkers working long hours, and assembly-line workers relative to skilled trades workers or workers in non-assembly facilities, have a higher risk of hypertension, CVD, and psychological disorders. Occupational disease surveillance and disease prevention programs need to fully utilize such administrative data.

Assessing the contribution of working conditions to socioeconomic disparities in health: a commentary.

INTRODUCTION: Occupational health researchers can play a pivotal role in increasing our understanding of the role of physical and psychosocial working conditions in producing socioeconomic health disparities and trends of increasing socioeconomic health disparities, contributing to interventions to reduce such disparities, and helping to improve public education materials on this subject. However, a number of methodological challenges in this field need to be considered. METHODS: Commentary, including a review of selected studies. RESULTS/CONCLUSION: Research needs to be guided by models of the associations between social (socioeconomic position (SEP), race/ethnicity, immigration status, and gender) and occupational variables and health, to avoid inappropriate control for confounding, and to specify causal pathways (mediation) and interaction effects. Different approaches to the theory and measurement of SEP also need to be tested.

Job Stress and Health of Elementary and Secondary School Educators in the United States.

Elementary and secondary school educators face many work stressors, which appear to be increasing due to economic, political, and social trends. Therefore, we analyzed data from a 2017 national American Federation of Teachers survey of U.S. education staff, including data from two New York School districts that have adopted collaborative labor-management practices. The national American Federation of Teachers sample of educators reported significantly higher prevalences of several work stressors and poorer physical and mental health compared to the U.S. workers overall, adjusted for age, gender, and race/ethnicity. Compared with educators nationally, educators in districts with collaborative labor-management practices did not have a consistently higher or lower prevalence of work stressors or poorer health. Findings suggest the importance of reducing work stressors among U.S. educators. Results should be interpreted with caution due to the low educator survey response rate.

The effect of exposure to long working hours on ischaemic heart disease: 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 experts. Evidence from mechanistic data suggests that exposure to long working hours may cause ischaemic heart disease (IHD). 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 IHD 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 IHD (three outcomes: prevalence, incidence and mortality). DATA SOURCES: We developed and published a protocol, applying the Navigation Guide as an organizing systematic review framework where feasible. We searched electronic databases for potentially relevant records from published and unpublished studies, including MEDLINE, 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) workers in the formal and informal economy in any WHO and/or ILO Member State but excluded children (aged < 15 years) and unpaid domestic workers. We included randomized controlled trials, cohort studies, case-control studies and other non-randomized intervention studies which contained 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 IHD (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 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-effect meta-analysis. Two or more review authors assessed the risk of bias, quality of evidence and strength of evidence, using Navigation Guide and GRADE tools and approaches adapted to this project. RESULTS: Thirty-seven studies (26 prospective cohort studies and 11 case-control studies) met the inclusion criteria, comprising a total of 768,751 participants (310,954 females) in 13 countries in 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 (30 studies) or self-reported physician diagnosis (7 studies). The outcome was defined as incident non-fatal IHD event in 19 studies (8 cohort studies, 11 case-control studies), incident fatal IHD event in two studies (both cohort studies), and incident non-fatal or fatal ("mixed") event in 16 studies (all cohort studies). Because we judged cohort studies to have a relatively lower risk of bias, we prioritized evidence from these studies and treated evidence from case-control studies as supporting evidence. For the bodies of evidence for both outcomes with any eligible studies (i.e. IHD incidence and mortality), we did not have serious concerns for risk of bias (at least for the cohort studies). No eligible study was found on the effect of long working hours on IHD prevalence. Compared with working 35-40 h/week, we are uncertain about the effect on acquiring (or incidence of) IHD of working 41-48 h/week (relative risk (RR) 0.98, 95% confidence interval (CI) 0.91 to 1.07, 20 studies, 312,209 participants, I2 0%, low quality of evidence) and 49-54 h/week (RR 1.05, 95% CI 0.94 to 1.17, 18 studies, 308,405 participants, I2 0%, low quality of evidence). Compared with working 35-40 h/week, working ≥55 h/week may have led to a moderately, clinically meaningful increase in the risk of acquiring IHD, when followed up between one year and 20 years (RR 1.13, 95% CI 1.02 to 1.26, 22 studies, 339,680 participants, I2 5%, moderate quality of evidence). Compared with working 35-40 h/week, we are very uncertain about the effect on dying (mortality) from IHD of working 41-48 h/week (RR 0.99, 95% CI 0.88 to 1.12, 13 studies, 288,278 participants, I2 8%, low quality of evidence) and 49-54 h/week (RR 1.01, 95% CI 0.82 to 1.25, 11 studies, 284,474 participants, I2 13%, low quality of evidence). Compared with working 35-40 h/week, working ≥55 h/week may have led to a moderate, clinically meaningful increase in the risk of dying from IHD when followed up between eight and 30 years (RR 1.17, 95% CI 1.05 to 1.31, 16 studies, 726,803 participants, I2 0%, moderate quality of evidence). Subgroup analyses found no evidence for differences by WHO region and sex, but RRs were higher among persons with lower SES. Sensitivity analyses found no differences by outcome definition (exclusively non-fatal or fatal versus "mixed"), outcome measurement (health records versus self-reports) and risk of bias ("high"/"probably high" ratings in any domain versus "low"/"probably low" in all domains). CONCLUSIONS: We judged the existing bodies of evidence for human evidence as "inadequate evidence for harmfulness" for the exposure categories 41-48 and 49-54 h/week for IHD prevalence, incidence and mortality, and for the exposure category ≥55 h/week for IHD prevalence. Evidence on exposure to working ≥55 h/week was judged as "sufficient evidence of harmfulness" for IHD incidence and mortality. Producing estimates for the burden of IHD attributable to exposure to working ≥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.

Selected occupational characteristics and change in leukocyte telomere length over 10 years: The Multi-Ethnic Study of Atherosclerosis (MESA).

Telomere length (TL) is considered as a marker of cell senescence, but factors influencing the rate of TL attrition are not well understood. While one previous study reported the association of occupation and TL, many subsequent studies have failed to find the association. This may be due to heterogeneity within the samples and cross-sectional designs. This longitudinal study examines two occupational characteristics, occupational complexity and hazardous conditions, as predictors of TL attrition in gender- and race/ethnicity-stratified analysis. Leukocyte TL (expressed as T/S ratio) was measured twice over a 10-year period in a multi-racial sample (n = 914). Linear mixed effect models were used to estimate TL attrition associated with occupational complexity and hazardous conditions. Analysis was stratified by gender and race/ethnicity (white, African American, and Latino) and controlled for baseline age, baseline TL, and time since baseline. Higher occupational complexity was associated with slower rates of TL attrition only among white men. Hazardous conditions were not associated with TL attrition for any gender-and-race/ethnicity stratified group. Occupational complexity may influence TL attrition, but the different findings for white men and other groups suggest that a more comprehensive framework is needed to better understand the potential link between occupational characteristics and biological aging.

A systematic review of the job-stress intervention evaluation literature, 1990-2005.

Ninety reports of systematic evaluations of job-stress interventions were rated in terms of the degree of systems approach used. A high rating was defined as both organizationally and individually focused, versus moderate (organizational only), and low (individual only). Studies using high-rated approaches represent a growing proportion of the job-stress intervention evaluation literature. Individual-focused, low-rated approaches are effective at the individual level, favorably affecting individual-level outcomes, but tend not to have favorable impacts at the organizational level. Organizationally-focused high- and moderate-rated approaches are beneficial at both individual and organizational levels. Further measures are needed to foster the dissemination and implementation of systems approaches to examining interventions for job stress.

Explaining racial/ethnic differences in all-cause mortality in the Multi-Ethnic Study of Atherosclerosis (MESA): Substantive complexity and hazardous working conditions as mediating factors.

Research on racial/ethnic health disparities and socioeconomic position has not fully considered occupation. However, because occupations are racially patterned, certain occupational characteristics may explain racial/ethnic difference in health. This study examines the role of occupational characteristics in racial/ethnic disparities in all-cause mortality. Data are from a U.S. community-based cohort study (n=6342, median follow-up: 12.2 years), in which 893 deaths (14.1%) occurred. We estimated mortality hazard ratios (HRs) for African Americans, Hispanics, and Chinese Americans compared with whites. We also estimated the proportion of the HR mediated by each of two occupational characteristics, substantive complexity of work (e.g., problem solving, inductive/deductive reasoning on the job) and hazardous conditions (e.g., noise, extreme temperature, chemicals), derived from the Occupational Information Network database (O*NET). Analyses were adjusted for age, sex, nativity, working status at baseline, and study sites. African Americans had a higher rate of all-cause death (HR 1.41; 95% confidence interval [CI]: 1.19-1.66) than whites. Chinese-American ethnicity was protective (HR 0.59, CI: 0.40-0.85); Hispanic ethnicity was not significantly different from whites (HR 0.88; CI: 0.67-1.17). Substantive complexity of work mediated 30% of the higher rate of death for African Americans compared with whites. For other groups, mediation was not significant. Hazardous conditions did not significantly mediate mortality in any racial/ethnic group. Lower levels of substantive complexity of work mediate a substantial part of the health disadvantage in African Americans. This job characteristic may be an important factor in explaining racial health disparities.

Job Strain, Occupational Category, Systolic Blood Pressure, and Hypertension Prevalence: The Multi-Ethnic Study of Atherosclerosis.

OBJECTIVE: To assess associations of occupational categories and job characteristics with prevalent hypertension. METHODS: We analyzed 2517 Multi-Ethnic Study of Atherosclerosis participants, working 20+ hours per week, in 2002 to 2004. RESULTS: Higher job decision latitude was associated with a lower prevalence of hypertension, prevalence ratio = 0.78 (95% confidence interval 0.66 to 0.91) for the top versus bottom quartile of job decision latitude. Associations, however, differed by occupation: decision latitude was associated with a higher prevalence of hypertension in health care support occupations (interaction P = 0.02). Occupation modified associations of sex with hypertension: a higher prevalence of hypertension in women (vs men) was observed in health care support and in blue-collar occupations (interaction P = 0.03). CONCLUSIONS: Lower job decision latitude is associated with hypertension prevalence in many occupations. Further research is needed to determine reasons for differential impact of decision latitude and sex on hypertension across occupations.

The changing organization of work and the safety and health of working people: a commentary.

Recent trends in the organization of work may affect worker health through a variety of pathways--by increasing the risk of stress-related illnesses, such as cardiovascular disease, musculoskeletal disorders, and psychological disorders, by increasing exposure to hazardous substances and violence on the job, or by affecting occupational health services and training programs. Much remains to be learned about the nature of changes in work organization, and how they affect worker health and safety. While available evidence is limited, such evidence suggests that recent trends in work organization may be increasing the risk of occupational illnesses. In a groundbreaking publication, the National Institute for Occupational Safety and Health has provided a concise summary of available knowledge and a detailed agenda for research and development.

Validity and reliability of a work history questionnaire derived from the Job Content Questionnaire.

Job design risk factors for hypertension and heart disease have often been assessed by the Job Content Questionnaire (JCQ). Job characteristics are typically assessed only once, however, which can result in misclassification and bias results toward the null. Newer approaches, which assess job characteristics over a working life, are hampered by the need to ask numerous questions about each job, increasing survey length and potentially reducing response rates. Participants in the Work Site Blood Pressure Study, a prospective study of psychosocial factors and ambulatory blood pressure, completed the JCQ about their current jobs. At later dates, 213 employed men, a subset of the original cohort, retrospectively completed the Work History Questionnaire (WHQ), a short version of the JCQ, for each past job. The WHQ exhibited moderate validity for assessing past job characteristics, a weak association with systolic blood pressure, and expected patterns of change over time. Thus, it may be a valuable tool for measuring the health effects of historical job characteristics, which often change over time.

Is job strain a major source of cardiovascular disease risk?

Empirical studies on job strain and cardiovascular disease (CVD), their internal validity, and the likely direction of biases were examined. The 17 longitudinal studies had the highest validity ratings. In all but two, biases towards the null dominated. Eight, including several of the largest, showed significant positive results; three had positive, nonsignificant findings. Six of nine case-control studies had significant positive findings; recall bias leading to overestimation appears to be fairly minimal. Four of eight cross-sectional studies had significant positive results. Men showed strong, consistent evidence of an association between exposure to job strain and CVD. The data of the women were more sparse and less consistent, but, as for the men, most of the studies probably underestimated existing effects. Other elements of causal inference, particularly biological plausibility, corroborated that job strain is a major CVD risk factor. Additional intervention studies are needed to examine the impact of ameliorating job strain upon CVD-related outcomes.

Lower socioeconomic status among men in relation to the association between job strain and blood pressure.

OBJECTIVES: This study attempted to determine whether the association between job strain (high job demands plus low job control) and blood pressure among men varies by socioeconomic status. METHODS: The cross-sectional associations between job strain and ambulatory blood pressure, by level of education, occupational status, and income, and the interaction between job strain and these measures of socioeconomic status were assessed by multiple linear regression, adjusted for age, race or ethnicity, body mass index, alcohol use, smoking, standing position, and worksite for 283 men, aged 30-60 years, from eight worksites in New York City. RESULTS: A substantial association between job strain and work ambulatory blood pressure was found among men with lower socioeconomic status, ranging from 2.7-11.8 mm Hg systolic to 1.9-6.1 mm Hg diastolic blood pressure, depending upon the measure of socioeconomic status examined. However, in the groups with high socioeconomic status, the association between job strain and ambulatory blood pressure at work was much smaller, the range in blood pressure being 0-5.3 (systolic) and 0.2-2.1 (diastolic) mm Hg. Two of the 10 tests of the interaction between job strain and socioeconomic status had a P-value of <0.05. CONCLUSIONS: These data provide evidence that the relationship between job strain and blood pressure is greater among men with lower socioeconomic status.

Working conditions and masked hypertension.

INTRODUCTION: Masked hypertension, i.e., normal clinic blood pressure but elevated blood pressure during normal daily activities as measured by ambulatory monitoring, is a common problem and a serious cardiovascular risk factor. Given previously reported associations between work stressors and ambulatory blood pressure, an inquiry into the relationship between work stressors and masked hypertension is warranted. OBJECTIVE: To assess the relationship between working conditions and masked hypertension. DESIGN: Cross-sectional study. SETTING: Hospital and home care employers in New York City. STUDY PARTICIPANTS: Forty-five male and 119 female hospital and home care employee volunteers wore an ambulatory blood pressure monitor during working hours. MAIN OUTCOME MEASURES: Masked hypertension was defined as work systolic ambulatory blood pressure ≥135 mmHg or diastolic ambulatory blood pressure ≥85 mmHg, and casual blood pressure <140/90 mmHg with no use of antihypertensive medications. Associations between work stressors and masked hypertension were tested by multiple logistic regression. RESULTS: Masked hypertension, observed in 24.0% of males and 17.6% of females with normal casual office obtained blood pressure, was associated with evening, night or rotating shiftwork (odds ratio (OR) 8.25, 95% confidence interval (CI) 2.11-40.31) and with the combination of job strain and effort-reward imbalance (OR 2.97, 95% CI 1.02-8.60) after controlling for age. Associations remained substantial, and statistically significant for shiftwork, after individual adjustment for each of 10 potential confounders. Masked hypertension was not associated with total weekly work hours. CONCLUSIONS: Masked hypertension is a significant individual and public health concern. Additional research is needed to clarify the role of work-related risk factors in the development of masked hypertension, and to develop an appropriate clinical and public health strategy for diagnosis, treatment and prevention.

Factorial invariance, scale reliability, and construct validity of the job control and job demands scales for immigrant workers: the multi-ethnic study of atherosclerosis.

Immigrants have a different social context from those who stay in their home country or those who were born to the country that immigrants now live. Cultural theory of risk perception suggests that social context influences one's interpretation of questionnaire items. We examined psychometric properties of job control and job demand scales with US- and foreign-born workers who preferred English, Spanish, or Chinese (n = 3,114, mean age = 58.1). Across all groups, the job control scale had acceptable Cronbach's alpha (0.78-0.83) and equivalent factor loadings (ΔCFI < 0.01). Immigrants had low alpha (0.42-0.65) for the job demands scale regardless of language, education, or age of migration. Two job-demand items had different factor loadings across groups. Among immigrants, both scales had inconsistent associations with perceived job stress and self-rated health. For a better understanding of immigrants' job stress, the concept of job demands should be expanded and immigrants' expectations for job control explored.