Mortality and morbidity patterns in ethnic minorities in England and Wales: evidence from the Office for National Statistics Longitudinal Study

Ethnic differences in the prevalence of diseases are known but the underlying causes and mechanisms remain unclear. The field of ethnic inequalities in health is relatively young in the UK, compromised by the lack of relevant data. It is, nevertheless, curious that while the UK has long provided some of the best empirical evidence and theoretical understanding of social inequalities in health, the exploration of ethnicity as an alternative dimension of social inequality is relatively recent. It was not until 1984 that first national study of ethnic differences in mortality was published. Between 1984 and 1996 the epidemiological knowledge base increased rapidly but weaknesses in these studies were evident. They were cross-sectional, small, based mainly on migrants of working ages from the Caribbean and the Indian subcontinent and tended to focus on CHD in South Asians and hypertension in Black Caribbeans. The use of ethnicity was linked to a biological or cultural concept, and the examination of the role of socio-economic environmental factors was cursory. The ten papers that I am submitting for this thesis were published between 1996 and 2004 and are located within this developing context of research in ethnic differences in health. At a time when there were no other national longitudinal studies of ethnic minorities, these papers were among the first to exploit the potential of the Office for National Statistics Longitudinal Study to examine ethnic differences in health. The findings of my submitted papers enhance the understanding of mortality and morbidity patterns in migrant groups and their children. Briefly, Papers I-III show that, in spite of the progressive improvement in socio-economic circumstances across three generations (grandparents, parents and children), Irish people living in England and Wales continued to show adverse mortality and cancer incidence patterns; Paper IV signals that addressing the risk of cancers is a public health priority for all minority groups, even though rates may be lower than the national average in some groups; Paper V shows the continuity of limiting long-term illness patterns across most migrant and UK-born minority groups; Papers VI and VII show that cumulative disadvantage was more common in South Asian and Caribbean migrants and that downward social mobility is associated with a disproportionate impact on limiting long-term illness in migrants; Papers VIII and IX show that the duration of residence in England and Wales and age at migration are important influences on the mortality of South Asian and Caribbean migrants in England and Wales; Paper X shows that there was little shift in mean birth weight between babies of migrant mothers and babies of UK-born minority mothers in the same ethnic group, which may have a continuing legacy on ethnic health inequalities, notably in cardiovascular disease. In summary, these published papers shed light on the social patterning of ethnic differences in health. This work stimulated the development of my current research programme. The papers included in the submission for the degree of PhD by published work are I. Harding S, Balarajan R. Patterns of mortality in second generation Irish living in England and Wales: longitudinal study. British Medical Journal 1996;312(7043):1389-1392. II. Harding S, Balarajan R. Mortality of third generation Irish people living in England and Wales: longitudinal study. British Medical Journal 2001;322(7284):466-467. III. Harding S. The incidence of cancers among second generation Irish living in England and Wales. British Journal of Cancer 1998;78(7):958-961. IV. Harding S, Rosato M. Cancer incidence among first generation Scottish, Irish, West Indian and South Asian migrants living in England and Wales. Ethnicity and Health 1999;4(1-2):83-92. V. Harding S, Balarajan R. Limiting long-term illness among Black Caribbeans, Black Africans, Indians, Pakistanis, Bangladeshis and Chinese born in the UK. Ethnicity and Health 2000;5(1):41-46. VI. Harding S, Balarajan R. Longitudinal Study of Socio-economic Differences in Mortality Among South Asian and West Indian Migrants. Ethnicity and Health 2001;6(2):121-128. VII. Harding S. Social mobility and self-reported limiting long-term illness among West Indian and South Asian migrants living in England and Wales. Social Science and Medicine 2003;56(2):355-361. VIII. Harding S. Mortality of migrants from the Indian subcontinent to England and Wales: Effect of duration of residence. Epidemiology 2003;14(3):287-292. IX. Harding S. Mortality of migrants from the Caribbean to England and Wales: effect of duration of residence. Int. J. Epidemiol. 2004;33(2):382-386. X. Harding S, Rosato M, Cruickshank JK. Lack of change in birthweights of infants by generational status among Indian, Pakistani, Bangladeshi, Black Caribbean, and Black African mothers in a British cohort study. Int. J. Epidemiol. 2004;33(6):1279-1285