Estimating the likelihood of cigarette maintenance and dual use among people using e-cigarettes for cigarette cessation: Analysis of the Population Assessment of Tobacco and Health Study Waves 5 and 6.

Introduction: This study longitudinally describes the relationship between frequency of e-cigarette use and past-month cigarette abstinence, dual use, and maintenance of cigarette smoking among adults in the US who ever used e-cigarettes for cigarette cessation.

Methods: Data were from the US Population Assessment of Tobacco and Health Study Waves 5 (2018/19; baseline) and 6 (2021; follow-up). The sample was restricted to adults who used cigarettes and e-cigarettes in the past-month and ever used e-cigarettes to quit smoking at baseline. The primary predictor was baseline daily e-cigarette-use, and outcomes at follow-up were past-month cigarette abstinence, and multiple past-month cessation outcomes: a. cigarette maintenance; b. dual use; c. dual abstinence; and, d. past-month cigarette abstinence. We used weighted multivariable logistic and multinomial regression models, adjusting for demographics and baseline daily cigarette smoking.

Results: Among adults who ever used e-cigarettes to quit cigarettes, more daily e-cigarette users than non-daily (36.7 % vs 8.4 %) were cigarette abstinent and had higher odds of cigarette abstinence at follow-up (AOR:1.9, 95 % CI:1.1, 3.2). Daily e-cigarette (vs. non-daily) users had a higher likelihood of cigarette abstinence than cigarette maintenance (RRR:7.1, 95 % CI:3.8, 13.0). Compared to dual use, there was a higher likelihood of cigarette abstinence among daily e-cigarette users (vs. non-daily) (RRR:2.7; 95 % CI:1.5,4.9).

Conclusions: Daily e-cigarette use among individuals who used e-cigarettes to quit cigarette smoking predicts past-month cigarette abstinence. Daily e-cigarette use is associated with a higher likelihood of cigarette abstinence than cigarette maintenance, and a higher likelihood of cigarette abstinence than dual use at follow-up.