Background The UK smoking prevalence is decreasing, however, the inequality gap is increasing. A new UK Tobacco Strategy is being finalised and it urgently needs further underpinning research.Smoking cessation services (SCS) contributed around 15% of the reduction in UK smoking prevalence between 2001–2016. However, even these benefits are in jeopardy, given the proposed further funding cuts to SCS. Using a previously validated microsimulation model, we quantitively compared three future SCS scenarios: maintaining, disinvesting, or enhancing services.

Methods We modelled the effectiveness and equity impacts of three scenarios over a 20-year time horizon:

A) a baseline of maintaining current SCS levels and trends;

B) assuming disinvestment (no SCS);

C) an enhanced SCS enabling 30% of current smokers, aged between 30–79 years, to be supported in smoking cessation every five years. We used the validated IMPACT _HINT microsimulation, an implementation of the IMPACT _NCD framework, to estimate changes in smoking prevalence, disease burden, and economic impact. We simulated close-to-reality smoking histories, smoking-related diseases and lag times to disease. Population data were drawn from the Health Survey for England (HSE). We assumed the SCS one-year overall effectiveness of 8% quitting (reflecting published studies). We modelled the relapse probability post-cessation conditional on deprivation and years since cessation, informed by HSE. Standard UK Treasury discount rates were applied, and we report costs from a societal perspective, but no SCS costs included. We used R v4.04.

Results Preliminary results suggest that the disinvestment scenario could result in approximately 3000 (95% Uncertainty Intervals: 990 to 5400) additional cases of cardiometabolic diseases, common cancers, and chronic obstructive pulmonary disease compared to the baseline scenario; most of them in the most deprived quintiles. The policy could result in about 4500 (2700 to 6700) additional deaths and £220m (110m to 380m) additional costs.In contrast, enhancing SCS could prevent or postpone approximately 1700 (420 to 3000) disease cases, most of them in the most deprived quintiles, and about 1700 (680 to 2700) fewer all-cause deaths. The policy could produce savings of £270m (120m to 460m) over the simulated period.

Conclusion Disinvesting in SCS is likely to be counterproductive, given their substantial health and economic benefits. Our model suggests that SCS provision needs to be continued at least at current levels. An enhanced service provision could be beneficial (after addressing issues of staff capacity and implementation costs).