Construction of Life-Course Occupational Trajectories: Evidence for Work as a Mediator of Racial Disparities in Hypertension

Association of Childhood Respiratory Status with Adult Occupational Exposures in a Birth Cohort

Rationale: People with better early-life respiratory health may be more likely to work in occupations with high workplace exposures in adult life compared with people with poor respiratory health. This may manifest as a healthy worker effect bias, potentially confounding the analysis of environmental exposure studies. Objectives: To evaluate associations between lung function in adolescence and occupational exposures at initial adult employment. Methods: The TCRS (Tucson Children's Respiratory Study) is a long-term prospective study of respiratory health beginning at birth. Associations between respiratory function at age 11 years and occupational exposures at first job at age 26 years were evaluated with logistic regression. We calculated percentage predicted values for forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1:FVC ratio, and forced expiratory flow from 25% to 75% of vital capacity at age 11. At the 26-year visit, participants self-reported occupational exposures to dust, smoke, and fumes/gas at first job in a standardized interview. Results: Forced expiratory flow from 25% to 75% of vital capacity and FEV1:FVC ratio at age 11 were positively associated with dust workplace exposures at the first job. Each 10% increase in percentage predicted prebronchodilator FEV1:FVC ratio was associated with 30% higher odds of workplace dust exposure (odds ratio for a 1% increase, 1.03 [95% confidence interval, 1.00-1.06; P = 0.045]). Similar associations were observed for FEV1 and FVC with workplace smoke exposures. We also observed modification by time at job: associations were stronger for those who remained in their jobs longer than 12 months. In addition, those with better function at age 11 were more likely to stay in their jobs longer than 12 months if their first jobs involved exposure to dust. Conclusions: Childhood lung function affects initial career choice. This study supports the premise of the healthy worker effect.

Association of Birthweight With Maternal Trajectories of Effort-Reward Imbalance and Demand-Control Across Pregnancy

OBJECTIVES

We assessed longitudinal patterns of effort-reward imbalance (ERI) and demand-control (DC) scores in pregnancy, and their association with newborn birthweight (BW).

METHODS

Sixty-one women were surveyed four times across pregnancy using the ERI and DC questionnaires. Trajectories of change in ERI and DC scores across pregnancy were constructed using growth mixture modeling, and their associations with BW were examined with generalized linear regression.

RESULTS

Declining ERI (diminishing effort with stable/increasing reward) was associated with higher BW (408 g; P = 0.015), and was robust to other work factors. DC trajectory was not significantly associated with BW.

CONCLUSIONS

Declining ERI may reflect improved work psychosocial climate across pregnancy, or a conscious reduction in effort. The ERI model may represent more flexible work characteristics, whereas job control may be less amenable to short-term alteration. Surveys in more diverse pregnant working populations could be recommended.

Longitudinal Assessment of Effort-Reward Imbalance and Job Strain Across Pregnancy: A Preliminary Study

OBJECTIVES

To assess longitudinal changes in occupational effort-reward imbalance (ERI) and demand-control (DC) scores across pregnancy and examine associations with blood pressure (BP) during pregnancy.

METHODS

A pilot repeated-measures survey was administered four times to a sample of working women across pregnancy using the ERI and DC instruments. Demographic data and blood pressure measurements were collected at each interval. Growth mixture modeling was used to examine trajectories of change in occupational characteristics. Associations with BP were examined using repeated-measures linear regression models.

RESULTS

ERI model components (effort, reward, and overcommitment) all declined across pregnancy while job control remained stable. Increasing ERI trajectory was associated with higher systolic BP (b = 8.8; p < 0.001) as was high overcommitment; declining ERI also showed a lesser association with higher BP. Associations between DC trajectories and BP were much smaller, and non-significant once controlled for overcommitment.

CONCLUSIONS

Self-assessed efforts, rewards, and overcommitment at work decline across pregnancy in our participants, while job control remains stable. Replication in a more diverse pregnant working population is warranted to confirm these results. These preliminary data suggest that further investigation into the factors that may be linked with improved work psychosocial climate during pregnancy may be useful in order to improve pregnancy outcomes.

Work Characteristics Associated with Physical Functioning in Women

Women make up almost half of the labor force with older women becoming a growing segment of the population. Work characteristics influence physical functioning and women are at particular risk for physical limitations. However, little research has explored the effects of work characteristics on women’s physical functioning. U.S. women between the ages of 50 and 79 were enrolled in the Women’s Health Initiative Observational Study between 1993 and 1998. Women provided job titles and years worked at their three longest-held jobs (n = 79,147). Jobs were linked to characteristics in the Occupational Information Network. Three categories of job characteristics related to substantive complexity, physical demand, and social collaboration emerged. The association between job characteristics and physical limitations in later life, measured using a SF-36 Physical Functioning score <25th percentile, was examined using modified Poisson regression. After controlling for confounding variables, high physical demand was positively associated with physical limitations (RR = 1.09 CI: 1.06–1.12) and substantively complex work was negatively associated (RR = 0.94, CI: 0.91–0.96). Jobs requiring complex problem solving, active learning, and critical thinking were associated with better physical functioning. Employers should explore opportunities to reduce strain from physically demanding jobs and incorporate substantively complex tasks into women’s work to improve long-term health.

Race-based job discrimination, disparities in job control, and their joint effects on health

OBJECTIVES

To examine disparities between job control scores in Black and White subjects and attempt to discern whether self-rated low job control in Blacks may arise from structural segregation into different jobs, or represents individual responses to race-based discrimination in hiring or promotion.

METHODS

Data from the National Survey of Midlife in the United States (MIDUS) were analyzed by mixed-effects linear regression and variance regression to determine the effects of grouping by occupation, and racial discrimination in hiring or promotion, on control scores from the Job Content Questionnaire in Black and White subjects. Path analyses were constructed to determine the mediating effect of discrimination on pathways from education and job control to self-rated health.

RESULTS

Black subjects exhibited lower mean job control scores compared to Whites (mean score difference 2.26, P < 0.001) adjusted for age, sex, education, and income. This difference narrowed to 1.86 when adjusted for clustering by occupation, and was greatly reduced by conditioning on race-based discrimination (score difference 1.03, P = 0.12). Path analyses showed greater reported discrimination in Blacks with increasing education, and a stronger effect of job control on health in Black subjects.

CONCLUSIONS

Individual racially-based discrimination appears a stronger determinant than structural segregation in reduced job control in Black workers, and may contribute to health disparities consequent on work.

Twelve-month employment intervention outcomes for drug-involved offenders

BACKGROUND

Employment has been identified as an important part of substance abuse treatment and is a predictor of treatment retention, treatment completion, and decreased relapse. Although employment interventions have been designed for substance abusers, few interventions have focused specifically on drug-involved offenders.

OBJECTIVES

The purpose of this study was to examine employment outcomes for drug-involved offenders who received a tailored employment intervention.

METHODS

In a randomized controlled trial, baseline and follow-up data were collected from 500 drug-involved offenders who were enrolled in a drug court program. Participants were randomly assigned to drug court as usual (control group) or to the employment intervention in addition to drug court.

RESULTS

Intent-to-treat analyses found that the tailored intervention was associated only with more days of paid employment at follow-up (210.1 vs. 199.9 days). When focusing on those with greater employment assistance needs, a work trajectory analyses, which took into account participants' pre-baseline employment pattern (negative or positive), revealed that intervention group participants had higher rates of employment (82.1% vs. 64.1%), more days paid for employment (188.9 vs. 157.0 days), and more employment income ($8623 vs. $6888) at follow-up than control group participants.

CONCLUSION

The present study adds to the growing substance abuse and employment literature. It demonstrates the efficacy of an innovative employment intervention tailored for drug-involved offenders by showing positive changes in 12-month employment outcomes, most strongly for those who have not had recent employment success.

Construction of early and midlife work trajectories in women and their association with birth weight

OBJECTIVES

We derived trajectories of the substantive complexity (SC) of work across mid-adult life in women and determined their association with term birth weight. SC is a concept that encompasses decision latitude, active learning, and ability to use and expand one's abilities at work.

METHODS

Using occupational data from the National Longitudinal Survey of Youth 1979 and O*NET work variables, we used growth mixture modeling (GMM) to construct longitudinal trajectories of work SC from the ages of 18 to 34 years. The association between work trajectories and birth weight of infants born to study participants was modeled using generalized estimating equations, adjusting for education, income, and relevant covariates.

RESULTS

GMM yielded a 5-class solution for work trajectories in women. Higher work trajectories were associated with higher term birth weight and were robust to the inclusion of both education and income. A work trajectory that showed a sharp rise after age 24 years was associated with marked improvement in birth weight.

CONCLUSIONS

Longitudinal modeling of work characteristics might improve capacity to integrate occupation into a life-course model that examines antecedents and consequences for maternal and child health.