Ethnic inequalities in mortality among the elderly in New Zealand

Abstract

To explore the contributions of socio-economic and demographic factors to ethnic disparity among older adult (65+) all cause and cause-specific mortality differentials among Māori, Pacific, Asians and non-Māori, non-Pacific non-Asian (nMnPnA) in New Zealand. We used univariate and multivariable Poisson regression models on linked New Zealand census and mortality data for older adults (65 years and above) (2001 to 2004, 1.3 million person years) with a comprehensive set of socio-economic indicators (education, income, car access, housing tenure, neighourhood deprivation). After controlling for the differences in age structure, Māori and Pacific males had a higher relative risk of dying than nMnPnA (RR=1.88 (95% Cl: 1.74, 2.04) and RR=1.75 (95% Cl: 1.54, 1.99) respectively) while Asian males had lower risk of dying (RR=0.66, 95% Cl: 0.57, 0.76). For females, the pattern was similar. The mortality gap between ethnic groups was mediated in part by socio-economic factors. The five socio-economic factors appear to account for greater than 40% of the excess mortality for Māori and Pacific men and about 34% for Māori females and 48% for Pacific females compared to nMnPnA men and nMnPnA women respectively. However, for Asian people, adjusting for socio-economic factors actually increases the relative gaps in mortality compared to nMnPnA by 18% for male and 71% for females. The results demonstrate that clear ethnic mortality gradients persist into old age and the mortality level of most groups was influenced by varying distribution of socio-economic factors. To reduce ethnic differences in old age mortality, inequalities as a result of socio-economic position should be reduced.