According to New Zealand 2006 Census data, smoking contributes to the 7- to 8-year gap between Māori and non-Māori life expectancy. The researchers specified six modelling scenarios, formed by combining two options for future per annum declines in mortality rates among never-smokers (1.5%/2.5% and 2.0%/3.5% for non-Māori/Māori; i.e. assuming a return to long-run trends of closing ethnic gaps as in pre-1980s decades), and three options for future per annum reductions in the mortality rate difference comparing current to never-smokers (0%, 1% and 2%). In 1996–1999, current smokers had an estimated 3.9 to 7.4 years less of life expectancy relative to never-smokers. This smoking difference in life expectancy was less among Māori than among non-Māori. If the 2006 census smoking prevalence remains unchanged into the future, this paper estimated that the difference in 2040 between Māori and non-Māori life expectancy will range from 1.8 to 6.1 years across the six scenarios and two sexes (average 3.8). If nobody smokes tobacco from 2020 onwards, the paper estimated additional gains in life expectancy for Māori ranging from 2.5 to 7.9 years (average 4.7) and for non-Māori ranging from 1.2 to 5.4 years (average 2.9). Going smokefree as a nation by 2020, compared to no change from the 2006 Census population smoking prevalence, is predicted to close ethnic inequalities in life expectancy by 0.3 to 4.6 years (average 1.8 years; consistently greater for females).
