Adherence to and Reasons for Premature Discontinuation From Stop-Smoking Medications: Data From the ITC Four-Country Survey

Nicotine replacement therapies (NRTs) have been demonstrated to be effective in clinical trials but may have lower efficacy when purchased over-the-counter (OTC). Premature discontinuation and insufficient dosing have been offered as possible explanations. The aims are to (a) investigate the prevalence of and reasons for premature discontinuation of stop-smoking medications (including prescription only) and (b) how these differ by type, duration of use, and source (prescription or OTC). The sample includes 1,219 smokers or recent quitters who had used medication in the last year (80.5% NRT, 19.5% prescription only). Data were from Waves 5 and 6 of the International Tobacco Control (ITC) Four-Country Survey. Most of the sample (69.1%) discontinued medication use prematurely. This was more common among NRT users (71.4%) than in users of bupropion and varenicline (59.6%). OTC NRT users were particularly likely to discontinue (76.3%). Relapse back to smoking was the most common reason for discontinuation of medication reported by 41.6% of respondents. Side effects (18.3%) and believing that the medication was no longer needed (17.1%) were also commonly reported. Of those who completed treatment, 37.9% achieved 6-month continuous abstinence compared with 15.6% who discontinued prematurely. Notably, 65.6% who discontinued because they believed the medication had worked were abstinent. Premature discontinuation of stop-smoking medications is common but is not a plausible reason for poorer quit outcomes for most people. Encouraging persistence of medication use after relapse or in the face of minor side effects may help increase long-term cessation outcomes.