Executive Summary

The Hospital Treatment of Tobacco Dependency (TTD) Model (Hospital-TTD-Mod) was developed to provide a robust, biologically realistic health economic evaluation of acute inpatient TTD services in England.

A review of existing decision-analytic models identified several methodological limitations, particularly the misapplication of absolute risk reductions to all treated patients and the conflation of admission events with unique individuals. Models tended to rely on evidence of the health outcomes for hospital readmissions from an evaluation of similar services in Ottawa, Canada (Mullen et al. 2016). This created constraints that the new models were not able to properly investigate the implications of variation in patient uptake of support on health outcomes, or how outcomes varied by condition and socio-demographic characteristics. These limitations impaired the ability to accurately model service improvements and health inequalities.

To address this, the Hospital-TTD-Mod introduces a deterministic, multi-year Lexis simulation architecture.

Key features of the model:

• Patient pathway modelling: Simulates realistic patient flows through the Acute Care inpatient pathway, separating initial clinical screening from specialist assessment and pharmacotherapy.

• Dual-perspective health economics: Calculates both the fixed costs of service delivery (evaluating short-term Trust budget impact) alongside the long-term societal cost-utility (incorporating lifetime savings and QALY gains).

• Health inequalities focus: Stratifies all clinical and economic outcomes by age, sex, and socioeconomic deprivation (Index of Multiple Deprivation).

This technical documentation outlines the complete methodology, data processing pipeline, and mathematical framework underpinning the new model.