Projecting future smoking prevalence to 2025 and beyond in New Zealand using smoking prevalence data from the 2013 Census.
van der Deen FS., Ikeda T., Cobiac L., Wilson N., Blakely T.
BACKGROUND: We have previously published a forecasting model of future smoking prevalence in New Zealand (NZ). Under business-as-usual (BAU) assumptions NZ's smokefree 2025 goal was not attained by any demographic group. However, the 2013 Census (which included a question on smoking) showed a greater than expected fall in prevalence, especially for Maori. We therefore aimed to provide upgraded projections to inform policy around tobacco endgame planning. METHOD: The previously developed dynamic forecasting model was re-specified using smoking prevalence data from the 2006 and 2013 censuses from NZ. Calculations included changes in initiation by age 20 years, and net annual cessation rates, by sex, age, and ethnicity (Maori vs non-Maori). Projections under 2006-2013 trends (adjusted for no tax rises since 2010), by sex and ethnicity were made out to 2025 and beyond. RESULTS: Between the 2006 and 2013 censuses (adjusted for no tax rises since 2010), initiation of daily smoking by age 20 years decreased annually by 3.4% (95% uncertainty interval 3.2% to 3.6%) and 2.7% (2.5% to 2.8%) for non-Maori men and women, and by 2.9% (2.6% to 3.2%) and 3.2% (2.9% to 3.5%) for Maori respectively. Annual net smoking cessation rates ranged from 3.7% to 7.7% across demographic groups. The revised projected smoking prevalence in 2025 (allowing for tax increases that have occurred from 2010 to 2014) was 8.3% and 6.4% for non-Maori, and 18.7% and 19.3% for Maori men and women, respectively. CONCLUSIONS: The upgraded smoking prevalence projections still suggests that the NZ Government's smokefree 2025 goal would not be attained by any demographic group. It is likely that more intensive existing interventions, or entirely novel ones, will be needed to achieve the 2025 endgame goal.