Theoretical impacts of a range of major tobacco retail outlet reduction interventions: modelling results in a country with a smoke-free nation goal

Objective To inform endgame strategies in tobacco control, this study aimed to estimate the impact of interventions that markedly reduced availability of tobacco retail outlets. The setting was New Zealand, a developed nation where the government has a smokefree nation goal in 2025. Methods Various legally mandated reductions in outlets that were phased in over 10 years were modelled. Geographic analyses using the road network were used to estimate the distance and time travelled from centres of small areas to the reduced number of tobacco outlets, and from there to calculate increased travel costs for each intervention. Age-specific price elasticities of demand were used to estimate future smoking prevalence. Results With a law that required a 95% reduction in outlets, the cost of a pack of 20 cigarettes (including travel costs) increased by 20% in rural areas and 10% elsewhere and yielded a smoking prevalence of 9.6% by 2025 (compared with 9.9% with no intervention). The intervention that permitted tobacco sales at only 50% of liquor stores resulted in the largest cost increase (∼$60/ pack in rural areas) and the lowest prevalence (9.1%) by 2025. Elimination of outlets within 2 km of schools produced a smoking prevalence of 9.3%. Conclusions This modelling merges geographic, economic and epidemiological methodologies in a novel way, but the results should be interpreted cautiously and further research is desirable. Nevertheless, the results still suggest that tobacco outlet reduction interventions could modestly contribute to an endgame goal