The treatment of tobacco dependence in patients admitted to hospital is a priority for the National Health Service in England. We aimed to conduct an economic analysis of a pilot ‘opt-out’ tobacco dependence treatment intervention adapted from the Ottawa Model of Smoking Cessation.

Observational cost analysis of an inpatient tobacco dependence treatment intervention, and matched cohort study comparing readmission costs between patients who received the intervention and benchmarked equivalents who did not.

11 acute inpatient wards in a major teaching hospital in London, England.

673 patients who smoked, admitted between 1 July 2020 and 30 June 2021.

The intervention consisted of the systematic identification of smoking status, automatic referral to tobacco dependence advisors, provision of pharmacotherapy and behavioural support throughout the hospital stay and telephone support for 6 months after discharge.

The primary outcomes were cost-per-patient, cost-per-quit and incremental cost effectiveness ratio among patients who received the intervention. The secondary outcomes were patient-level readmission costs and bed-days from 6 months after discharge, compared between the intervention group and a group of matched benchmark patients who smoked but did not receive the intervention.

The total cost of the intervention was £178 105. On the basis of 104 patients who reported not smoking at 6 months, the cost-per-quit was £1712.55, equating to an estimated age-adjusted incremental cost per life year gained of £3325. Among 611 patients who were successfully matched to a benchmark cohort, readmissions for patients in the intervention group cost £492 k less than their benchmark equivalents over 21 months from 1 January 2021 to 30 September 2022 (£266 k vs £758 k), incurred 414 fewer bed days (303 vs 717) and readmitted at a lower rate (5% vs 11%). There were reduced readmission rates and costs among all patients who received the intervention compared with their benchmarked equivalents, regardless of smoking status at 6 months, except among those who opted out.

A pilot ‘opt-out’ tobacco dependence treatment intervention implemented in an acute hospital setting in London demonstrated value for money through reduced readmission rates and costs among all patients who received it.