Electronic Cigarette Use and Related Factors among Active Duty Service Members in the U.S. Military

Electronic cigarettes (e-cigarettes) are increasingly used in the U.S.A. by young people. As young adults serve as the primary recruiting pool for military, active duty service members in military may be susceptible to using e-cigarettes. However, factors related to e-cigarette use in military population have rarely been studied. We aimed to identify factors associated with e-cigarette use and factors related to duration of use among active duty service members. Materials and Methods: Subjects (N = 2,467) from Fort Bragg Army Base, North Carolina and Lackland Air Force Base, Texas completed a self-administered questionnaire during July 2015 to May 2016 time frame. The questionnaire collected data on demographic and military characteristics, tobacco use (including e-cigarette use) and other information. Stepwise logistic regression was performed to identify significant factors associated with e-cigarette use. Stepwise linear regression was performed to identify factors associated with duration of use. Results: A total of 356 (14.4%) study participants reported ever use of e-cigarettes. There was no significant difference in prevalence of use between the two military installations (15.6% at Fort Bragg vs. 13.2% at Lackland, P = 0.097). Increased use of e-cigarettes was associated with young age (20-24 years old) (OR = 1.98, 95% CI = 1.22-3.22), enlisted military rank (E1-e4: OR = 2.45, 95% CI = 1.36-4.40; E5-e9: OR = 1.88, 95% CI = 1.10-3.21), low perception of harm (OR = 5.18, 95% CI = 3.65-7.34), former (OR = 9.12, 95% CI = 6.29-13.22) and current (OR = 13.24, 95% CI = 9.22-19.02) cigarette smoking, and former smokeless tobacco use (OR = 2.07, 95% CI = 1.33-3.22), former (OR = 2.62, 95% CI = 1.42-4.85) and current (OR = 2.82, 95% CI = 1.82-4.37) cigar or pipe smoking. However, serving mainly in combat unit during deployment was associated with decreased odds of use (OR = 0.57, 95% CI = 0.34-0.97). Among e-cigarette users, the number of years using e-cigarettes was significantly longer among the participants with lower perception of harm than those with higher perception of harm (0.82 vs. 0.22, P < 0.001), and the duration was longer among subjects who used e-cigarette with nicotine than those without nicotine (0.79 vs. 0.49, P = 0.003). Finally, reasons for use differed markedly by cigarette smoking status. Never smokers used e-cigarette for the taste or flavor, while cigarette smokers used e-cigarette to help quit tobacco or reduce tobacco use. Conclusion: Young age, lower military ranks, other tobacco use, and low perception of harm were associated with increased odds of using e-cigarettes, while serving in combat unit was associated with decreased odds of use in active duty service members. Low harm perception and using nicotine-containing e-cigarettes were associated with long duration of use. The reasons for using e-cigarettes differed by cigarette smoking status. Our study provides clues for future hypothesis-driven studies.