Impact of e-cigarette use among a cohort of American Indian cigarette smokers: associations with cigarette smoking cessation and cigarette consumption.

Introduction: Despite American Indian/Alaska Native (AI/AN) people having the highest prevalence of cigarette smoking nationwide, few studies have evaluated e-cigarette use among AI/AN adults who smoke. The primary objective of this observational pilot cohort study was to determine if e-cigarette use is associated with cigarette smoking cessation or reduction among adult AI individuals who smoke.
Methods: In 2016, we collected baseline survey and biomarker data among AI adults who smoke. The survey included questions about cigarette consumption and use of e-cigarettes and biomarkers, such as salivary cotinine markers and exhaled carbon monoxide. After 18 months, we repeated data collection, and asked about changes in cigarette smoking status and cigarettes per day (CPD). Comparisons between groups were performed using the χ ² test, Fisher's exact test or Wilcoxon rank-sum test.
Results: Of 375 baseline participants, 214 (57.07%) returned for follow-up and were included in analyses. Of these, 20 (9.3%) reported having stopped cigarette smoking and had biochemical verification of cigarette smoking abstinence. Among those who quit smoking, 15% were baseline e-cigarette users; while among those who continued to smoke at follow-up, about 11% were baseline e-cigarette users. This difference was not statistically significant (p=0.48). Among all those who continued to smoke at follow-up, there was no overall decrease in CPD, nor a significant difference in change in CPD between baseline e-cigarette users and non-users (p=0.98).
Conclusions: E-cigarette use at baseline was not associated with smoking cessation or a change in CPD in this cohort of AI adults who smoke after an 18-month follow-up period.
Competing Interests: Competing interests: JDD, coauthor, receives salary and equity interests from Bayesic Technologies.
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