Phyo Pyi Pyi, Bullen Christopher
School of Population Health, The University of Auckland, Auckland, New Zealand.
BMJ Public Health. 2025 Aug 28;3(2):e002853. doi: 10.1136/bmjph-2025-002853. eCollection 2025.
Illicit tobacco poses a significant challenge to public health efforts. New Zealand (NZ) stands out for its stringent tobacco control policies, but there are concerns that the size of the illicit market could grow. Estimating the extent of the illicit tobacco trade in NZ remains challenging due to the diverse methodologies used by various stakeholders over different years.
We did annual consumption gap analyses (CGA) from 2012 to 2023 by calculating the discrepancy between estimated cigarette smoking (factory-made cigarettes and roll-your-own cigarettes) and legal sales to examine trends in the illicit tobacco trade in NZ.
The proportion of illicit tobacco in the NZ market fluctuated between 2012 and 2023. The negative test statistic of Kendall's tau indicates a slightly downward trend, but the trend is weak and statistically insignificant. The negative percentage may reflect under-reporting or the absence of hidden populations' consumption estimates, or the overestimation of legal sales. Our analyses adjust for under-reporting of smoking by using an uplift factor of 1.23 and adopt a 'worst-case scenario' by using the upper limit of the 95% CI around the point estimate for the proportion of daily smokers.
CGA is a useful tool for estimating the illicit tobacco trade, but it depends on accurate and valid estimates of consumption, under-reporting and reporting of legal tobacco supply. It is most useful to estimate the trend rather than the absolute amount of illicit tobacco. In NZ, the estimated proportion of illicit tobacco fluctuated between 2012 and 2023, supported by the statistically insignificant Mann-Kendall test. Reducing demand for smoking, alongside more vigorous border scrutiny and enforcement, is the most effective strategy for tackling the illicit trade. NZ's Smokefree aspirations to see prevalence drop to 5% or lower in the next few years may, therefore, significantly reduce the size of the illicit tobacco market.
非法烟草对公共卫生工作构成重大挑战。新西兰以其严格的烟草控制政策脱颖而出，但有人担心非法市场规模可能会扩大。由于不同年份各利益相关方使用的方法多样，估算新西兰非法烟草贸易的规模仍然具有挑战性。
我们通过计算估计的吸烟量（工厂制造的香烟和自卷烟）与合法销售量之间的差异，对2012年至2023年进行了年度消费差距分析（CGA），以研究新西兰非法烟草贸易的趋势。
2012年至2023年期间，新西兰市场上非法烟草的比例有所波动。肯德尔tau检验的负统计量表明略有下降趋势，但该趋势较弱且在统计上不显著。负百分比可能反映了报告不足或未对隐性人群的消费进行估算，或者合法销售被高估。我们的分析通过使用1.23的提升因子来调整吸烟报告不足的情况，并采用“最坏情况”，即使用每日吸烟者比例点估计值周围95%置信区间的上限。
消费差距分析是估算非法烟草贸易的有用工具，但它取决于对消费、报告不足和合法烟草供应报告的准确有效估计。它最有助于估计趋势而非非法烟草的绝对数量。在新西兰，2012年至2023年期间非法烟草的估计比例有所波动，曼-肯德尔检验在统计上不显著支持了这一点。减少吸烟需求，同时加强边境检查和执法，是应对非法贸易的最有效策略。因此，新西兰无烟的目标是在未来几年将吸烟率降至5%或更低，这可能会显著减少非法烟草市场的规模。
