Cumulative Working Life Course Exposures and Mortality: Findings From the Panel Study of Income Dynamics

2. Research Support & Collaborators

3. Take Away Messages Aging and life course perspective provides new models for occupational safety and health Spending a working life in a job with little or moderately little control increases the hazard of death The primary hypothesis of the job strain model (high strain) not supported Spending a working life in a passive job increases the hazard of death It�s not income its labor market conditions!

4. Labor Markets and Health Framework

5. What Are Labor Market Experiences? The nature of work � what work is done and how it is done in the labor market The availability of work � how a person is connected to the labor market Over time these experiences create a �working life course� that defines a citizen's adult life

6. Problems to Overcome: Measuring Objective Exposures Defines the occupational health approach by identifying interventions Reduces potential confounding of measuring exposure and outcome in same instrument Often accomplished through using a job exposure matrix

7. Problems to Overcome:Developing Life Course Exposure Models Defines the salience of a labor markets and health approach Requires multiple measurements of exposure Integrates time, context and transitions into the dose-response relationship

8. The Problem of A Dynamic Cohort: Left Censoring

9. The Problem of A Dynamic Cohort: Mid Censoring

10. Problems to Overcome:Integrating Health Into Exposure Models Health is an intervening variable Requires multiple measurements of health Highlights the practical importance of health care in managing work life exposure

11. Hypothesis A working life course characterized by a large amount of time in �hazardous� psychosocial and physical work conditions places a person at an increased risk of death job strain (high demands & low control) low job control lack of job content heavy physical demands

12. The Panel Study of Income Dynamics On-going household-level panel study started in 1968 Response rates high Sample representative of US households with exception of recent immigrants Annual data on labor market experience and health: eliminates recall bias problems permits the examination of reciprocal effects allows short and long-term effects to be estimated Data publicly available with exception of mortality data

13. Cohort Definition 1969 Initiate Cohort - Followed Through 1991 Start Counting Deaths in 1970 Through 1992 Exclude Any Observation With Less Than Three Years of Exposure Information 1885 Deaths Goes to 963 Deaths and 157845 PY

14. Cohort Definition:Exclusion Biases

15. Exposure Measurement:Using The Job Exposure Matrix Job Characteristics Scoring System (Schwartz et al, 1988) Psychological Job Demands: the perceived demands from the job and others in the workplace Job Control: the opportunity to decide what work to do and how to do it Work Support: supervisor and coworker assistance in getting the job done and listening Physical Exertion: the physical demands of the job Job Security: the degree a worker feels likely to have a job or useful skills in the future

16. Job Strain

17. Exposure Measurement:Cumulative Life Time Exposure Calculation Life Course Exposure Quartile 1 2 3 4 1970 Welder 1 0 0 0 1971 Punch & Stamper .5 .5 0 0 1972 Not Working .5 .5 0 0 1973 Machine Op. .75 .25 0 0 1974 Carpenter .5 .25 .25 0

18. How Far Out After Working Stops Can Work Exposure Affect Mortality? No strong biological model for latency that allows specification of lag time Could look at death on the job? Five year latent effect for last year of exposure information (follows McDonough et al., 1997) Control for retirement transition critical

19. Establish Mortality Windows

20. Confounders Included In Models Sociodemographics: Age (time varying), Male, Black, Year, Race by Age Interaction Income: Log Family Income 1992 Constant $ (time varying), family size (time varying) Health: Disability (baseline only) Retirement (time varying) and retirement by age interaction Unemployment Status (time varying)

21. Statistical Analysis Logistic regression: logit h(t)=XA + Z(t)B Data structured as person-year file Odds ratios approximate instantaneous hazard rate Robust variance estimation using sandwich technique Time-varying weight to account for initial selection probability and non-response Cluster on person to adjust for interdependence of observations

22. Analytic Samples

23. Death Rates (Per 1000) For 1970-1990

24. Job Decision Latitude (Average Level) For 1970-1990

25. Job Strain and Mortality5-Year Window

26. Job Strain and Mortality10-Year Window

27. Karasek Job StrainFindings: Full Models*

28. Low Job Control Increases Risk

29. Methodological Problem? Of �Over Adjustment� Often discussed in this literature around education Major problem with disability as time varying covariate that not only estimates health but some of exposure effect Appropriate model is disability as both confounder and intermediate variable (Robbins, 1985)

30. Conclusions Job Control Finding Confirms Other Recent Longitudinal Evidence from Marmot and Johnson Strong Controls for Income, Retirement, Unemployment and Health Indicates Modest Amounts of Control Needed to Reduce Risk

31. Conclusions Lack of Effect of Job Strain and Psychological Job Demands Replicates Research of Marmot, Johnson, Bosma, Eaton, Steenland No Effect Found Using Alternative Exposure Formulation Consistent Finding Using Job Exposure Matrices Where Intra-Occupational Variability in Demands Substantial Lack of Full Spectrum of Occupational Mix, Only 222 Occupations In The US Out Of 444

32. Conclusions Passive Work Finding New Suggests importance of job content in addition to job structure The boredom of work could lead to the need stay attractive and cumulative allostatic load Lack of meaningful work could lead to substance use and abuse or mental health problems

33. Conclusions Lack of Income Effect New! Perhaps due to healthy worker effect Like Marmot in Whitehall we find it�s work not social status or social position per se that significantly contributes to mortality

34. Conclusions

35. Labor Markets and Health Framework

36. Further Thoughts New job exposure matrices should be developed (job control) Relationship of exposures to objective work conditions should be demonstrated Develop models that capture labor market experiences (working and not working) as careers Not all exposures are created equal - need to attend to period and age-graded effects

37. Further Thoughts Need to move from total mortality to cause of death Need to introduce widowhood transition Need to explore gender and race interactions Need to model health as an intermediate variable