Cost-effectiveness of e-cigarettes for smoking cessation at homeless support centres: SCeTCH cRCT

Background: While smoking is common among those experiencing homelessness, the effectiveness of an e-cigarette intervention to reduce smoking in this population is unclear.
Objective: To determine the cost-effectiveness of providing an e-cigarette for smoking cessation in homeless support centres compared to usual care.
Design and methods: A multi-centre two-arm cluster randomised controlled trial, with data collection time points at baseline, 4-, 12- and 24-weeks post-baseline.
Setting and participants: Adults (aged 18+) who smoked daily and accessed 32 homeless support centres across six areas of Great Britain received either intervention (EC, n=239 in 16 centres) or usual care (UC, n=236 in 16 centres), by centre (cluster) randomisation.
Intervention: The EC was the provision of an e-cigarette starter kit plus 4-weeks supply of e-liquids. The UC comprised very brief advice for smoking cessation and signposting to local stop smoking services.
Main outcome measures: The total costs included costs of EC/UC, costs of smoking cessation outside of the trial, and costs of general health care services use over 24 weeks. Quality-adjusted Life Years (QALYs) were derived from EQ-5D-5L administered at each data collection point. An incremental cost-effectiveness ratio (ICER) was calculated for 24 weeks using the difference between groups in total costs and QALYs, with cost-effectiveness acceptability curve constructed based on bootstrap to examine uncertainty. A long-term model was employed to project a lifetime ICER with probability sensitivity analysis to examine uncertainty.
Data sources: The analysis over 24 weeks was based on research team records and data collected via self-reported questionnaires. Unit costs for valuation were extracted from published secondary sources. The parameters of the long-term model were based on the 24 week results and published secondary sources.
Results: Mean intervention costs were estimated at £92 (SE £0) per participant in the EC group and at £50 (SE £0) per participant in the UC group. Mean total costs per participant were estimated at £3,859 (SE £441) in the EC group and £2,716 (SE £386) in the UC group. Mean QALYs were estimated at 0.303 (SE 0.008) in the EC group and 0.295 (SE 0.010) in the UC group. Adjusting for baseline covariates and respective baseline values, EC group were £1,267 (95% CI £600 to £1,938) more costly and yielded 0.007 (95% CI -0.017 to 0.027) more QALYs, than UC. The ICER was calculated at £181,000 per QALY gain, with probability of EC being cost-effective between the ICER thresholds of £20,000 to £30,000 per QALY gain at 0.9%-3.5%. The life-time model projected the ICER at £38,360 per QALY gained, with the probability of EC being cost-effective between £20,000 and £30,000 from 47.6% to 49.6%.
Limitations: The imbalance in missing data led to some uncertainty in the results and healthcare costs recorded in the trial may not reflect the health needs of this population.
Conclusions: Providing e-cigarettes for smoking cessation in homeless support centres was more costly than usual care but the small increase in QALYs was not significant.
Future work: Future work should aim to maximise quit rates while being cost-effective and therefore implementable.