Cost effectiveness of interventions to reduce relapse to smoking following smoking cessation.

AIMS To determine the incremental cost effectiveness of nicotine replacement therapy (NRT), bupropion and varenicline for preventing relapse to smoking when used by abstinent smokers DESIGN SETTING AND PARTICIPANTS Cohort simulation and sensitivity analyses combining cost and health service data with systematic review estimates for the effectiveness of NRT, bupropion and varenicline when used by abstinent quitters to prevent their relapse to smoking. MEASUREMENTS Incremental health gain in Quality Adjusted Life Years (QALYs) generated by each drug compared to 'no intervention'. FINDINGS Bupropion resulted in an incremental QALY increase of 0.07 with a concurrent cost saving of £68; NRT and varenicline both caused incremental QALYs increases of 0.04 at costs of £12 and £90 respectively, although varenicline findings were based on data from a single clinical trial and require cautious interpretation. Even after extensive sensitivity analyses with substantial varying of key model parameters, cost effectiveness of all drugs remained. Cost effectiveness ratios only exceeded the UK National Institute of Clinical Excellence (NICE) benchmark of £20 000 per QALY when drug treatment effects were postulated to last for no longer than 1 year; or, for NRT and varenicline, efficacy was reduced to 10% of that observed in clinical trials. CONCLUSIONS Bupropion, nicotine replacement therapy and varenicline appear cost effective at preventing relapse to smoking by smokers who are in quit attempts and have recently become abstinent; they have comparable cost effectiveness to smoking cessation interventions. Widespread use of these effective relapse prevention treatments could promote substantial health gain at an acceptable cost to health providers.