Understanding population trends and process (UPTAP): Inaugural Conference

1. Understanding population trends and process (UPTAP): Inaugural Conference 30 March 2006 Claudia Thomas Centre for Paediatric Epidemiology & Biostatistics Institute of Child Health University College London

2. Mid-Career fellowship • Start date: May 2007 • Duration: 2 years • Supervisor: • Professor Chris Power (ICH) • Collaborators: • Professor Heather Joshi, Centre for Longitudinal Studies, Institute of Education, London • Professor Stephen Stansfeld, Queen Mary’s School of Medicine and Dentistry, London

3. How does employment affect cardiovascular risk? A life-course approach in the 1958 cohort • AIM • To understand the role of labour market participation as a process that leads to social inequalities in cardiovascular disease.

4. Background: employment and health • Structure and organisation of paid employment has adverse consequences for various health outcomes: • Lack of job security associated with poor self-reported health, chronic disease and psychological distress (Whitehall II). • (Virtanen et al. JECH, 2002, 56:569; Ferrie et al. BMJ, 2001, 322:647; Ferrie et al. BMJ, 1995, 311:1264) • Unemployment related to mortality and psychological distress • (Thomas et al. JECH 2005, 59:243; Pensola et al. Soc Sci Med, 2004, 58:2149; Murphy & Athanasou, J Occ Org Psych, 1999, 72:83) • Combination of work and motherhood (“role overload”) has adverse consequences for health. • (Weatherall et al. Soc Sci Med, 1994, 38:285)

5. Background: employment and CVD • Most studies have looked at psycho-social affects of work on cardiovascular disease: • Job strain, job demands, decision latitude • (Agardh et al. Diabetes Care, 2003, 26:719; Kuper et al. JECH, 2003, 57:147) • Less is known about aspects of employment on cardiovascular disease: • Evidence for relationship with lower socio-economic position • (Lawlor et al. Am J Pub Hlth, 2005, 95:91; Feldman & Steptoe, Hlth Psych, 2003, 22:398) • Relationship with shift-work • (Knutsson & Boggild, Rev Environ Hlth, 2000, 15:359; Boggild & Knutsson, Scand J Work & Environ Hlth, 1999, 25:85)

6. Objectives • To study the direct relationships between employment characteristics and adult cardiovascular risk markers. • To study the indirect pathways: diet, physical activity, weight gain. • Take into account social processes occurring earlier in life, such as education, that determine how individuals arrive in their occupational destinations. • Understand how the more complex patterns of labour market participation experienced by women, such as, the combined roles of work and motherhood, are related to cardiovascular disease.

7. Methods • Dataset: 1958 British birth cohort • Outcomes: cardiovascular markers measured at age 45 years (BP, HbA1c, triglycerides, cholesterol, waist/hip circumference, BMI) • Main exposures: employment information back to age 16y • Mediators: health behaviours in adulthood (smoking, alcohol, diet, physical activity); adiposity throughout the lifecourse • Other covariates/confounders: SEP in childhood and adulthood, early environment (birth weight, health in childhood/adolescence) home circumstances in adulthood, education, region of residence.

8. Methods: Analyses • Direct relationship between labour market participation and cardiovascular measures: • Cross-sectional and longitudinal associations • Whether observed associations are explained by earlier life factors (neonatal circumstances, education, childhood health, parents SEP) • Indirect associations between labour market participation and cardiovascular measures • Mediators: weight change, health behaviours • Statistical methods: linear and logistic regression; multilevel modelling; structural equations (pathway analysis)

9. 1958 British birth cohort (NCDS) • Perinatal Mortality Survey • All live births one week in March 1958 • England, Scotland and Wales • ~17000 • Followed up: • age 7y (1965) • 11y (1969) • 16y (1974) • 23y (1981) • 33y (1991) • 42y (2000) • 45y (2003) – biomedical survey

10. 1958 cohort biomedical survey • At age 45 years • MRC “Health of the Public” grant (Prof C Power, Prof D Strachan) • Nurse interviews • Physical measurements, e.g. height, weight, BP • Blood collection • Nurse administered questionnaire (CAPI) • Self completed CAPI section: sensitive information

11. 17638 eligible cases in March 1958 18558 “total cohort” sample 12069 biomedical issued sample (includes 31 dress rehearsal cases) 9377 productive cases (includes 29 dress rehearsal cases, 9 ‘lost productives’ with no CAPI data) 1958 cohort biomedical sample 920 immigrants added NCDS1-NCDS3 6489 cases not in biomedical sample: 1196 ineligible - dead 1236 ineligible - living outside GB 1041 permanent refusals 31 NCDS6 proxy respondents 2985 not issued for other reasons 93 ineligible cases (28 dead, 65 living outside GB) 1804 refusals (includes 1 case whose data was withdrawn after interview) 697 non-contacts 98 other unproductives Liz Fuller, 2006

12. 1958 cohort: employment patterns • Historical context • Cohort entered labour market in mid-1970s to early 1980s • Unemployment had started to rise, subsequent periods of boom and recession • Women’s participation had also increased: part-time, low level and low-paying jobs • During cohort member’s working lives, reorganisation and restructuring of work: eg increased computer use

13. 1958 cohort: economic activity Source: Changing Britain, Changing Lives. E. Ferri, J. Bynner, M. Wadsworth, 2003

14. 1958 cohort: employment characteristics • Occupation • Grade (Registrar general) • Hours of work • At 33y, 50% of male employees compared to 11% of female employees worked more than 40 hours per week • Night work done more frequently by men than women • Paid versus self-employment • Approximately 14% self-employed (more men than women)

15. 1958 cohort: work and health Key publications on labour participation and health in the cohort to date: Llena-Nozal et al. The effect of work on mental health: does occupation matter? Health Economics, 2004, 13: 1045-1062 Power et al. Childhood and adulthood risk factors for socio-economic differentials in psychological distress: evidence from the 1958 British birth cohort. Social Science & Medicine, 2002, 55: 1989-2004 Matthews & Power. Socio-economic gradients in psychological distress: a focus on women, social roles and work-home characteristics. Social Science & Medicine, 2002, 54: 799-810 Matthews et al. Gender, work roles and psychosocial work characteristics as determinants of health. Social Science & Medicine, 1998, 46: 1417-1424 Montgomery et al. Health and social precursors of unemployment in young men in Great Britain. JECH, 1996, 50: 415-422 Joshi, et al. Employment after childbearing and women’s subsequent labour force participation: Evidence from the 1958 birth cohort. J Population Economics, 1996, 9:325-348

16. Acknowledgements • ESRC UPTAP secondary data analysis initiative for provision of Mid-Career Fellowship • MRC funding of biomedical survey • Centre for Longitudinal Studies: management of the1958 cohort; co-ordination of follow-up surveys; data collection and provision of data.