Cigarette Smoking Relapse Among People Who Switched to E-cigarettes or Other Tobacco Products.

Introduction: Little is known about how quitting and switching to other tobacco products affects cigarette smoking relapse. Additionally, there is no consensus on the best definition of relapse.

Aims and methods: Respondents who smoked cigarettes at baseline, had quit by the first follow-up, and completed the second follow-up survey in the Population Assessment of Tobacco and Health Study were included. We employed multivariable logistic regressions to assess the association between non-cigarette tobacco use at follow-up 1 and smoking relapse risk at follow-up 2, considering three definitions of relapse.

Results: 54.8% of the 1686 respondents who had recently quit smoking cigarettes relapsed according to Measure I (any smoking in the past 12 months), 40.3% using Measure II (any smoking in the past 30 days), and 30.1% using Measure III (smoked on ≥3 days in the past 30 days). Compared with no tobacco use at follow-up 1, any tobacco use was associated with increased relapse risk using Measure I (adjusted risk difference [aRD] = 7.14, CI [0.64 to 13.64]). The association was nonsignificant using Measures II (aRD = -0.53, CI [-6.62 to 5.56]) or III (aRD = -4.11, CI [-9.28 to 1.06]). Similarly, exclusive e-cigarette use was significantly associated with Measure I, but not with Measures II or III.

Conclusions: Compared with respondents who had recently quit and were tobacco-free at follow-up 1, those who switched to non-cigarette tobacco products may be more likely to slip but showed no difference in the likelihood of relapse when employing a relapse definition less strict than any smoking in the past 12 months.

Implications: The distinction between a slip and relapse needs to be considered more carefully, with researchers undertaking further studies that help us contemplate how we should define relapse. People who recently quit smoking cigarettes and switched to non-cigarette tobacco products (including e-cigarettes) may be more likely to slip compared to people who recently quit and were tobacco-free, but they are not clearly more likely to relapse.