Patterns of disparity: ethnic and socio-economic trends in breast cancer mortality in New Zealand.

Abstract

OBJECTIVE: To test whether trends in breast cancer mortality varied by ethnicity and socio-economic position during the 1980s and '90s in New Zealand. METHODS: Four cohorts of the entire New Zealand population for 1981-84; 86-89; 91-94 and 96-99 allowed direct determination of socio-economic trends in breast cancer mortality. For ethnicity, unlinked routine census and mortality data were used with adjustment factors for undercounting of Māori and Pacific deaths. RESULTS: Māori and non-Māori non-Pacific mortality rates changed little until mid-1990s with Māori experiencing 25% higher mortality. In 1996-99, Māori rates increased notably to become 68% higher than non-Māori non-Pacific (SRR 1.68..