Cost-effectiveness of a specialist smoking cessation package compared with standard smoking cessation services for people with severe mental illness in England: a trial-based economic evaluation from the SCIMITAR+ study

Aims: To evaluate the cost-effectiveness of a specialist smoking cessation package for people with severe mental illness. Design: Incremental cost-effectiveness analysis was undertaken from the UK National Health Service and Personal Social Services perspective over a 12-month time horizon. Total costs, including smoking cessation, health-care and social services costs and quality-adjusted life years (QALYs), derived from the five-level EuroQol 5-dimension (EQ-5D-5 L), collected from a randomized controlled trial, were used as outcome measures. The bootstrap technique was employed to assess the uncertainty. Setting: Sixteen primary care and 21 secondary care mental health sites in England. Participants: Adult smokers with bipolar affective disorder, schizoaffective disorder or schizophrenia and related illnesses (n = 526). Intervention and comparator: A bespoke smoking cessation (BSC) package for people with severe mental illness offered up to 12 individual sessions with a mental health smoking cessation practitioner versus usual care (UC). Of the participants who were randomized, 261 were in UC group and 265 were in BSC group. Measurements: BSC intervention cost was estimated from the treatment log. Costs of UC, health-care and social services and EQ-5D-5 L were collected at baseline, 6- and 12-month follow-ups. Incremental costs and incremental QLAYs were estimated using regression adjusting for respective baseline values and other baseline covariates. Findings: The mean total cost in the BSC group was £270 [95% confidence interval (CI) = –£1690 to £1424] lower than in the UC group, while the mean QALYs were 0.013 (95% CI = –0.008 to 0.045) higher, leading to BSC dominating UC (76% probability of cost-effective at £20 000/QALY). Conclusions: A bespoke smoking cessation package for people with severe mental illness is likely to be cost-effective over 12 months compared with usual care provided by the UK's National Health Service and personal social services.