Abstract PR01: Factors associated with dual use of electronic cigarettes among adult American Indians who smoke: A Cherokee Nation cohort study

Significance: American Indians (AI) have a higher prevalence of smoking, higher prevalence of electronic cigarette (EC) use, and higher cancer mortality than most other racial groups, particularly in Oklahoma. However, AI are rarely included in studies of EC use among smokers. As many individuals who smoke also use ECs to reduce harms from cigarettes, understanding correlates of using both products by AI merits greater attention.

Methods: In Oklahoma in 2016, 375 AI who smoke and were ages 18 years and older completed a survey collecting demographic information, personal and family history of cancer, perceptions of EC harm and benefits, measures of smoking and dependence, other tobacco use, and EC use by spouse or partner. We defined dual users as using EC within 30 days and every day or some days (n = 44; 12%) and compared dual users to EC never users (n = 137; 37%).

Results: Dual users were younger than never users (median 36 vs. 46 years, respectively; p = .01) but did not differ significantly by sex, education, or income. Dual users did not differ significantly from never users in self-reported general health status, personal history of cancer, or other smoking-related medical conditions. Dual users more often reported history of depression (56% vs. 29%; p < .01) and a family history of cancer (lung, head, neck, other) marginally more often than did never users (58% vs. 41%, p = 0.05). While no significant differences were noted for perceived harms of smoking or secondhand smoke, low perceived harm of ECs was more frequent among dual users than never users (64% vs. 24%; p < .01) as well as secondhand vapor (77% vs. 29%; p < .01). Dual users agreed more often that ECs help to quit smoking (75% vs. 16%; p < .01) and are less harmful than smoking (70% vs. 17%; p < .01). Only 9% of dual users did not know or were uncertain about EC harms or benefits, compared to 29% of never users for harms (p < .01) and 38% for benefits (p < .01). Differences between groups were not significant for cigarette consumption, salivary cotinine levels, or smoking dependence scales, but dual users reported a likelihood to quit smoking more often than never users (86% vs. 65%; p = .01), and more often tried to quit in past 12 months (55% vs. 32%; p = .01). Dual users significantly (p ≤ .01) more often ever tried snus (36% vs. 10%), cigars (68% vs. 46%), cigarillos (82% vs. 56%), and hookah (50% vs. 14%) but no differences in ever use of other smokeless tobacco. Among those living with a spouse/partner, dual and never users did not differ in spouse/partner smoking, but dual users much more frequently lived with a spouse/partner who uses ECs (45% vs. 6%; p < .01).

Conclusions: EC use is a potential, albeit unproven, harm reduction strategy for people who smoke. The American Cancer Society strongly discourages dual use of EC and cigarettes. This exploratory study of AI found several significant associations with dual EC and cigarette use, but cigarette consumption was similar between groups. It remains to be determined whether ECs will have a role in smoking cessation or reducing cancer health disparities among AI.

This abstract is also being presented as Poster A004.

Citation Format: Dorothy A. Rhoades, Ashley L. Comiford, Justin D. Dvorak, Kai Ding, Leslie Driskill, Michelle Hopkins, Theodore L. Wagener, Paul Spicer, Mark P. Doescher. Factors associated with dual use of electronic cigarettes among adult American Indians who smoke: A Cherokee Nation cohort study [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr PR01.

E-cigarettes and Tobacco Exposure Biomarkers among American Indian Smokers

Objective We assessed associations between electronic cigarette (e-cigarette) use and smoking-related measures among American Indians (AIs) who smoke. MethodsWe collected baseline survey and smoking biomarker data in a cohort of 375 adult AI smokers at a Cherokee Nation healthcare facility in Oklahoma. We used multivariate logistic and linear regression analyses to determine associations between e-cigarette use and smoking-related characteristics, including biomarkers. ResultsCurrent e-cigarette users were more likely than never users to report a quit attempt in the past 12 months (current vs never adjusted odds ratio (AOR) = 2.24 [95% CI 1.20-4.16]). Current and past e-cigarette users were more likely than never users to report a likelihood to quit smoking (current vs never AOR = 2.97 [95% CI 1.34-6.56]; past vs never AOR = 1.77 [95% CI 1.08-2.91]). E-cigarette use was not significantly associated with confidence to quit smoking, cigarette packs smoked per day, or cotinine levels. ConclusionsE-cigarette use was associated with previous and future quit attempts, but not with reductions in cigarette smoking or confidence in quitting. This suggests that many dual users might benefit from the addition of evidence-based smoking cessation treatments.