Evaluating the public health impact of partial and full tobacco flavour bans: A simulation study.

Background: Tobacco flavours such as menthol and fruits, which appeal to youth, remain unregulated in Western Pacific countries. Our goal was to evaluate the potential impact of tobacco flavour bans in Singapore, which has the region's highest flavoured cigarette market share.

Methods: Using an open-cohort microsimulation model, we estimated the impact of full ban and partial ban (excluding menthol and clove) scenarios versus the status quo (no ban) over a 50-year horizon. We used a Markov chain with four states (never, unflavoured, flavoured and ex-smokers), updating each individual's state across each year. We estimated between-state transition probabilities using Markov chain Monte Carlo, with prior distributions derived from national survey data.

Findings: Without a ban, smoking prevalence gradually increases from 12.7% (2018) to 15.2% (2068). In both ban scenarios, smoking prevalence decreases immediately after the ban: by 1.6% points in the full ban, and 0.4% points in the partial ban scenario. In addition, there is a sustained long-term impact as fewer initiate. In the full ban scenario, smoking prevalence decreases to 10.6% by 2068 with a cumulative gain of over 40,000 QALYs. In the partial ban scenario, it remains stable at 12.5% with a cumulative gain of over 20,000 QALYs.

Interpretations: A tobacco flavours ban would reap substantial public health benefits in countries that, like Singapore, have a large flavoured cigarette market share, especially with a full ban compared to a partial ban not covering menthol or clove-flavoured cigarettes.

Funding: This study was funded by the Singapore Ministry of Health.