Measuring ethnicity in New Zealand: Developing tools for health outcomes analysis

Objective. This study examines the development of new tools for analysing links between ethnicity and health outcomes. In a New Zealand context, it focuses on (1) how ethnicity is increasingly articulated as a social construct, (2) how individuals belonging to more than one ethnic group have been recorded and reported in research, and (3) health research and policy implications of the growing proportion of New Zealanders who claim multi-ethnic affiliations. Design. New Zealand provides a microcosm in which to consider ethnicity, indigeneity, migration and intermarriage, and their interacting effects on society, culture, identity and health outcomes. Against a backdrop of historical debates about the measurement of race, and then ethnicity, the paper explores recent changes in the recording and reporting of ethnicity in the five-yearly Census of Population and Dwellings, and in death registrations. These changes are then considered in relation to the study of ethnic health disparities and the development of policies to overcome them. Results. In the 2001 Census, of those who responded to the ethnicity question, at a level 1 classification 7.9% gave more than one response. In relation to the indigenous people of New Zealand, of all those who recorded M (a) over bar ori as one or more of their ethnic groups, only 56% recorded M (a) over bar ori only. In the younger age groups, less than half the M (a) over bar ori ethnic group were M (a) over bar ori only. Single ethnic categories disguise considerable within-group diversity in outcomes. Conclusion. While single ethnic group disparity studies have been useful in the past, we suggest that more sophisticated ways of conceptualising and analysing ethnicity data in relation to health disparities are now required in New Zealand. Based on the New Zealand experience, we also suggest that as international migration continues, and as intermarriage becomes more frequent in most countries, there will be pressure to move from single group race-based measures towards culturally-based complex ethnicity measures.