Trends in colorectal cancer mortality by ethnicity and socio-economic position in New Zealand, 1981-99: one country, many stories
Version of Record online: 25 SEP 2007
Australian and New Zealand Journal of Public Health
Volume 30, Issue 1, pages 64–70, February 2006
How to Cite
Shaw, C., Blakely, T., Sarfati, D., Fawcett, J. and Peace, J. (2006), Trends in colorectal cancer mortality by ethnicity and socio-economic position in New Zealand, 1981-99: one country, many stories. Australian and New Zealand Journal of Public Health, 30: 64–70. doi: 10.1111/j.1467-842X.2006.tb00088.x
- Issue online: 25 SEP 2007
- Version of Record online: 25 SEP 2007
- Revision requested: May 2005 Accepted: June 2005
Background:Ethnicity and socio-economic position are important determinants of colorectal cancer (CRC) mortality. In this paper, we determine trends in colorectal cancer mortality by ethnicity and socioeconomic position in New Zealand.
Methods:Cohort studies of the entire New Zealand population for 1981-84, 1986-89, 1991-94 and 1996-99 (linking Census and mortality datasets) allowed direct determination of trends in CRC mortality by income and education. For ethnicity, we used routine unlinked Census and mortality data, but with correction factors applied for undercounting of Mǎori and Pacific deaths.
Results:Ethnicity: CRC mortality trends varied markedly. There were small (10-20%) decreases among non-Mǎori non-Pacific people, a 50% increase among Mǎori, and up to 10-fold increase among Pacific people. By 1996-99, all three ethnic groups had similar CRC mortality.
Socio-economic position:For females, differences in CRC mortality by education and income increased over time e. g. poor females had a 40% higher CRC mortality than rich females in 1996-99, compared with no difference in 1981-84 (p for trend 0.04). In men, increases in inequality were seen by income but not education.
Conclusion:The observed ethnic trends probably reflect differential trends in exposure to etiological risk factors. Social inequalities in colorectal cancer mortality appear to be increasing.