Ethnic counts on mortality, New Zealand cancer registry and census data: 2006–2011

Abstract

AIMS: The New Zealand Census-Mortality Study demonstrated substantial undercounting of Māori/Pacific deaths on mortality relative to census data for the 1980s/1990s. This ethnic undercounting also exists in the New Zealand Cancer Registry. We aim to provide an update on this ‘numerator-denominator’ bias. METHODS: 2006 Census anonymously and probabilistically linked to subsequent mortality and Cancer Registry data allowing comparison of ethnicity recording. RESULTS: A ‘total’ definition of ethnicity showed the closest agreement between census and other data. Census:mortality ratios are close to 1.0 for Māori (1.01), Pacific (0.98) and ‘non-Māori non-Pacific non-Asian’ (nonMPA) people (0.98), ..