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

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

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.

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)

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)

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.

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.

Methods: Analyses 1.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) 2.Indirect associations between labour market participation and cardiovascular measures Mediators: weight change, health behaviours 3.Statistical methods: linear and logistic regression; multilevel modelling; structural equations (pathway analysis)

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

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

1958 cohort biomedical sample 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 eligible cases in March productive cases (includes 29 dress rehearsal cases, 9 ‘lost productives’ with no CAPI data) biomedical issued sample (includes 31 dress rehearsal cases) “total cohort” sample 920 immigrants added NCDS1-NCDS3 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

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

1958 cohort: economic activity 33y (1991)42y (2000) Men (%) Women (%) Men (%) Women (%) Economically active Paid employment Full-time Part-time Unemployed6232 Economically inactive N Source: Changing Britain, Changing Lives. E. Ferri, J. Bynner, M. Wadsworth, 2003

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)

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: 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: Matthews & Power. Socio-economic gradients in psychological distress: a focus on women, social roles and work-home characteristics. Social Science & Medicine, 2002, 54: Matthews et al. Gender, work roles and psychosocial work characteristics as determinants of health. Social Science & Medicine, 1998, 46: Montgomery et al. Health and social precursors of unemployment in young men in Great Britain. JECH, 1996, 50: Joshi, et al. Employment after childbearing and women’s subsequent labour force participation: Evidence from the 1958 birth cohort. J Population Economics, 1996, 9:

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.