1  Introduction

1.1 Background and policy context

Smoking remains one of the leading causes of preventable illness and early death in England, and people who smoke are admitted to hospital more often than people who don’t. The NHS Long Term Plan (UK National Health Service (NHS) 2019) committed the NHS to offering tobacco dependence treatment to everyone admitted to hospital who smokes. In acute hospitals the treatment follows the NHS Inpatient Tobacco Dependence Treatment Care Bundle, set out in the NHS Standard Treatment Plan (Papadakis et al. 2023): at admission, every patient is asked whether they smoke, and those who do are advised, offered NRT and referred to the trust’s tobacco dependence team on an opt-out basis; in hospital, a specialist advisor assesses them and agrees a treatment plan; at discharge, they get at least two weeks of stop smoking aids and are referred for specialist support after discharge; and after discharge, the trust team follows them up by phone.

Hospital-TTD-Mod was developed to help NHS England, trusts and local health systems plan and evaluate these services. It started from a review, commissioned by NHS England, of the models used to make the case for hospital tobacco dependence treatment. A first version, in Excel, was used in the evaluation of the QUIT programme in South Yorkshire, supported by Yorkshire Cancer Research. The model was then rewritten in R, so that it could do more and be run for every ICB and trust in England.

1.2 Why a new model

The earlier models mostly took their effects from the evaluation of the Ottawa Model for Smoking Cessation in Canada (Mullen et al. 2017) and applied them to local hospital data. The review found three problems that tend to overstate the savings:

  • The effect was given to the wrong people. Ottawa’s 11.6 point fall in the proportion of patients readmitted was applied to every patient who took up support, when only those who quit can benefit, and most patients seen do not quit.

  • Admissions were counted as patients. A fall in the proportion of patients readmitted was used as a fall in readmissions, or the other way round.

  • One effect for every condition. The same reduction was applied to every future admission, whatever the condition and however long since the patient quit, though the risk of heart disease falls quickly after quitting and the risk of lung cancer slowly.

Hospital-TTD-Mod gives the benefit only to the extra people who quit because of the service, counts patients and admissions separately, and works out the admissions avoided condition by condition as the risk falls with time since quitting. Because it models the pathway step by step, it can also show what changes in the service (more patients seen, more registering for support after discharge) would do, and how the results differ by deprivation, age and sex.

1.3 Objectives and scope

The model estimates, for the service compared with usual care in 2019:

  • the activity of the service and its cost to trusts, year by year;

  • the extra people who quit at 4 weeks, 12 months and for life;

  • the admissions, bed days, costs and deaths avoided in the five years after each year’s patients are treated;

  • the lifetime NHS savings and QALYs of the extra people who quit for life;

  • value for money from the trust’s side (Tier 1) and the health system’s (Tier 2); and

  • how these differ by deprivation, age and sex, and between scenarios for the roll-out and for the service itself.

The scope is adult inpatients in the 129 trusts with inpatient tobacco dependence services (126 acute trusts and 3 community trusts with inpatient beds). Maternity, mental health and outpatient services are not included. Specialist support after discharge is included as a cost to the health system, from whichever local route provides it.

1.4 Structure of this document

Chapter 2 describes the data sources and Chapter 3 how they are prepared, including the hospital population and the calibration of smoking prevalence. Chapter 4 describes the clinical pathway and Chapter 5 the epidemiology: how quitting changes admissions and deaths in the five years after discharge. Chapter 6 describes the economics. Chapter 7 describes the checks on the model, including the calibration to the referral data and the comparison with the Ottawa and London evaluations, and the next chapter the analysis of inequalities. Chapter 8 is a guide to running the model.