Introduction: This study assessed quit attempts among adults who use cigarettes either exclusively or with e-cigarettes in Mexico, where non-daily smoking predominates.

Methods: An open cohort of Mexican adults who smoke was surveyed every four months from November 2018 to March 2021. Participants followed to the next survey were analyzed (n = 2220 individuals, 4560 observations). Multinomial logistic models regressed smoking quit attempts reported at the followup survey (ref = no attempt; tried to quit; sustained attempt of ≥30 days) on e-cigarette use frequency (none = ref; 1-2 days/week; ≥3 days/week), adjusting for sociodemographics and smoking-related variables. Additional models subdivided e-cigarette users by intentions to quit smoking in the next six months (i.e., yes/no), use of nicotine (i.e., yes/no), and vaping device used (i.e., open/closed).

Results: At 4-month follow-up, 32.7 % had tried to quit, and 2.9 % had quit for 30 days or more. Compared to those who smoke exclusively, occasional, and frequent e-cigarette users were more likely to try to quit (Adjusted Relative Risk Ratio or ARRR = 1.26 and 1.66, respectively) but no more likely to sustain their quit attempt. Among those who intended to quit smoking, e-cigarette users were no more likely to either try or sustain quit attempts. Furthermore, use of e-cigarettes with nicotine (59.6 %) was unassociated with cessation except that those who frequently used e-cigarettes with nicotine were more likely to try to quit than those who smoke exclusively (ARRR = 1.88). Device type used was not differentially associated with outcomes.

Conclusions: Mexicans who smoke and use e-cigarettes appear more likely than those who smoke exclusively to try to quit but not to sustain abstinence.