Association of Electronic Cigarette Regulations With Electronic Cigarette Use Among Adults in the United States | Tobacco and e-Cigarettes | JAMA Network Open | JAMA Network
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Figure.  Age-Standardized Weighted Prevalence of Current Electronic Cigarette Use Among US Adults, Behavioral Risk Factor Surveillance System, 2016 to 2017
Age-Standardized Weighted Prevalence of Current Electronic Cigarette Use Among US Adults, Behavioral Risk Factor Surveillance System, 2016 to 2017

Prevalence estimates were weighted. The prevalence in Guam was 6.2% (not shown).

Table 1.  Participant Characteristics, Behavioral Risk Factor Surveillance System, 2016 to 2017
Participant Characteristics, Behavioral Risk Factor Surveillance System, 2016 to 2017
Table 2.  Proportion of States With Laws Regarding Electronic Cigarette Use and Proportion of Participants Exposed to Those Lawsa
Proportion of States With Laws Regarding Electronic Cigarette Use and Proportion of Participants Exposed to Those Lawsa
Table 3.  Association of State Laws Regarding Electronic Cigarettes With Current Electronic Cigarette Use, Behavioral Risk Factor Surveillance System, 2016 to 2017
Association of State Laws Regarding Electronic Cigarettes With Current Electronic Cigarette Use, Behavioral Risk Factor Surveillance System, 2016 to 2017
1.
National Academies of Sciences Engineering and Medicine.  Public Health Consequences of E-Cigarettes. Washington, DC: National Academies Press; 2018.
2.
Dinakar  C, O’Connor  GT.  The health effects of electronic cigarettes.  N Engl J Med. 2016;375(14):1372-1381. doi:10.1056/NEJMra1502466PubMedGoogle ScholarCrossref
3.
Grana  R, Benowitz  N, Glantz  SA.  E-cigarettes: a scientific review.  Circulation. 2014;129(19):1972-1986. doi:10.1161/CIRCULATIONAHA.114.007667PubMedGoogle ScholarCrossref
4.
Mirbolouk  M, Charkhchi  P, Kianoush  S,  et al.  Prevalence and distribution of e-cigarette use among U.S. adults: Behavioral Risk Factor Surveillance System, 2016.  Ann Intern Med. 2018;169(7):429-438. doi:10.7326/M17-3440PubMedGoogle ScholarCrossref
5.
Jamal  A, King  BA, Neff  LJ, Whitmill  J, Babb  SD, Graffunder  CM.  Current cigarette smoking among adults: United States, 2005-2015.  MMWR Morb Mortal Wkly Rep. 2016;65(44):1205-1211. doi:10.15585/mmwr.mm6544a2PubMedGoogle ScholarCrossref
6.
McMillen  RC, Gottlieb  MA, Shaefer  RM, Winickoff  JP, Klein  JD.  Trends in electronic cigarette use among U.S. adults: use is increasing in both smokers and nonsmokers.  Nicotine Tob Res. 2015;17(10):1195-1202. doi:10.1093/ntr/ntu213PubMedGoogle ScholarCrossref
7.
Bao  W, Xu  G, Lu  J, Snetselaar  LG, Wallace  RB.  Changes in electronic cigarette use among adults in the United States, 2014-2016.  JAMA. 2018;319(19):2039-2041. doi:10.1001/jama.2018.4658PubMedGoogle ScholarCrossref
8.
Bao  W, Liu  B, Du  Y, Snetselaar  LG, Wallace  RB.  Electronic cigarette use among young, middle-aged, and older adults in the United States in 2017 and 2018  [published online October 14, 2019].  JAMA Intern Med. doi:10.1001/jamainternmed.2019.4957PubMedGoogle Scholar
9.
Yeh  JS, Bullen  C, Glantz  SA.  E-Cigarettes and smoking cessation.  N Engl J Med. 2016;374(22):2172-2174. doi:10.1056/NEJMclde1602420PubMedGoogle ScholarCrossref
10.
Hartmann-Boyce  J, Begh  R, Aveyard  P.  Electronic cigarettes for smoking cessation.  BMJ. 2018;360:j5543. doi:10.1136/bmj.j5543PubMedGoogle ScholarCrossref
11.
Kalkhoran  S, Glantz  SA.  E-cigarettes and smoking cessation in real-world and clinical settings: a systematic review and meta-analysis.  Lancet Respir Med. 2016;4(2):116-128. doi:10.1016/S2213-2600(15)00521-4PubMedGoogle ScholarCrossref
12.
McRobbie  H, Bullen  C, Hartmann-Boyce  J, Hajek  P.  Electronic cigarettes for smoking cessation and reduction.  Cochrane Database Syst Rev. 2014;(12):CD010216. doi:10.1002/14651858.CD010216.pub2PubMedGoogle Scholar
13.
Bullen  C, Howe  C, Laugesen  M,  et al.  Electronic cigarettes for smoking cessation: a randomised controlled trial.  Lancet. 2013;382(9905):1629-1637. doi:10.1016/S0140-6736(13)61842-5PubMedGoogle ScholarCrossref
14.
Halpern  SD, Harhay  MO, Saulsgiver  K, Brophy  C, Troxel  AB, Volpp  KG.  A pragmatic trial of e-cigarettes, incentives, and drugs for smoking cessation.  N Engl J Med. 2018;378(24):2302-2310. doi:10.1056/NEJMsa1715757PubMedGoogle ScholarCrossref
15.
Borrelli  B, O’Connor  GT.  E-Cigarettes to assist with smoking cessation.  N Engl J Med. 2019;380(7):678-679. doi:10.1056/NEJMe1816406PubMedGoogle ScholarCrossref
16.
Hajek  P, Phillips-Waller  A, Przulj  D,  et al.  A randomized trial of e-cigarettes versus nicotine-replacement therapy.  N Engl J Med. 2019;380(7):629-637. doi:10.1056/NEJMoa1808779PubMedGoogle ScholarCrossref
17.
Soneji  S, Barrington-Trimis  JL, Wills  TA,  et al.  Association between initial use of e-cigarettes and subsequent cigarette smoking among adolescents and young adults: a systematic review and meta-analysis.  JAMA Pediatr. 2017;171(8):788-797. doi:10.1001/jamapediatrics.2017.1488PubMedGoogle ScholarCrossref
18.
Goniewicz  ML, Knysak  J, Gawron  M,  et al.  Levels of selected carcinogens and toxicants in vapour from electronic cigarettes.  Tob Control. 2014;23(2):133-139. doi:10.1136/tobaccocontrol-2012-050859PubMedGoogle ScholarCrossref
19.
Goniewicz  ML, Kuma  T, Gawron  M, Knysak  J, Kosmider  L.  Nicotine levels in electronic cigarettes.  Nicotine Tob Res. 2013;15(1):158-166. doi:10.1093/ntr/nts103PubMedGoogle ScholarCrossref
20.
Goniewicz  ML, Smith  DM, Edwards  KC,  et al.  Comparison of nicotine and toxicant exposure in users of electronic cigarettes and combustible cigarettes.  JAMA Netw Open. 2018;1(8):e185937. doi:10.1001/jamanetworkopen.2018.5937PubMedGoogle Scholar
21.
Hess  CA, Olmedo  P, Navas-Acien  A, Goessler  W, Cohen  JE, Rule  AM.  E-cigarettes as a source of toxic and potentially carcinogenic metals.  Environ Res. 2017;152:221-225. doi:10.1016/j.envres.2016.09.026PubMedGoogle ScholarCrossref
22.
Rubinstein  ML, Delucchi  K, Benowitz  NL, Ramo  DE.  Adolescent exposure to toxic volatile organic chemicals from e-cigarettes.  Pediatrics. 2018;141(4):e20173557. doi:10.1542/peds.2017-3557PubMedGoogle Scholar
23.
Allen  JG, Flanigan  SS, LeBlanc  M,  et al.  Flavoring chemicals in e-cigarettes: diacetyl, 2,3-pentanedione, and acetoin in a sample of 51 products, including fruit-, candy-, and cocktail-flavored e-cigarettes.  Environ Health Perspect. 2016;124(6):733-739. doi:10.1289/ehp.1510185PubMedGoogle ScholarCrossref
24.
Moheimani  RS, Bhetraratana  M, Yin  F,  et al.  Increased cardiac sympathetic activity and oxidative stress in habitual electronic cigarette users: implications for cardiovascular risk.  JAMA Cardiol. 2017;2(3):278-284. doi:10.1001/jamacardio.2016.5303PubMedGoogle ScholarCrossref
25.
Muthumalage  T, Prinz  M, Ansah  KO, Gerloff  J, Sundar  IK, Rahman  I.  Inflammatory and oxidative responses induced by exposure to commonly used e-cigarette flavoring chemicals and flavored e-liquids without nicotine.  Front Physiol. 2018;8:1130. doi:10.3389/fphys.2017.01130PubMedGoogle ScholarCrossref
26.
Carnevale  R, Sciarretta  S, Violi  F,  et al.  Acute impact of tobacco vs electronic cigarette smoking on oxidative stress and vascular function.  Chest. 2016;150(3):606-612. doi:10.1016/j.chest.2016.04.012PubMedGoogle ScholarCrossref
27.
Alzahrani  T, Pena  I, Temesgen  N, Glantz  SA.  Association between electronic cigarette use and myocardial infarction.  Am J Prev Med. 2018;55(4):455-461. doi:10.1016/j.amepre.2018.05.004PubMedGoogle ScholarCrossref
28.
Yan  XS, D’Ruiz  C.  Effects of using electronic cigarettes on nicotine delivery and cardiovascular function in comparison with regular cigarettes.  Regul Toxicol Pharmacol. 2015;71(1):24-34. doi:10.1016/j.yrtph.2014.11.004PubMedGoogle ScholarCrossref
29.
Vlachopoulos  C, Ioakeimidis  N, Abdelrasoul  M,  et al.  Electronic cigarette smoking increases aortic stiffness and blood pressure in young smokers.  J Am Coll Cardiol. 2016;67(23):2802-2803. doi:10.1016/j.jacc.2016.03.569PubMedGoogle ScholarCrossref
30.
Kalkhoran  S, Glantz  SA.  Modeling the health effects of expanding e-cigarette sales in the United States and United Kingdom: a Monte Carlo analysis.  JAMA Intern Med. 2015;175(10):1671-1680. doi:10.1001/jamainternmed.2015.4209PubMedGoogle ScholarCrossref
31.
US Food and Drug Administration, Department of Health and Human Services.  Deeming tobacco products to be subject to the Federal Food, Drug, and Cosmetic Act, as amended by the Family Smoking Prevention and Tobacco Control Act: restrictions on the sale and distribution of tobacco products and required warning statements for tobacco products—final rule.  Fed Regist. 2016;81(90):28973-29106.PubMedGoogle Scholar
32.
Public Health Law Center.  U.S. E-Cigarette Regulation: A 50-State Review. St Paul, MN: Tobacco Control Legal Consortium; 2018.
33.
Marynak  K, Kenemer  B, King  BA, Tynan  MA, MacNeil  A, Reimels  E.  State laws regarding indoor public use, retail sales, and prices of electronic cigarettes: U.S. states, Guam, Puerto Rico, and U.S. Virgin Islands, September 30, 2017.  MMWR Morb Mortal Wkly Rep. 2017;66(49):1341-1346. doi:10.15585/mmwr.mm6649a1PubMedGoogle ScholarCrossref
34.
Odani  S, Armour  BS, Graffunder  CM, Willis  G, Hartman  AM, Agaku  IT.  State-specific prevalence of tobacco product use among adults: United States, 2014-2015.  MMWR Morb Mortal Wkly Rep. 2018;67(3):97-102. doi:10.15585/mmwr.mm6703a3PubMedGoogle ScholarCrossref
35.
Hu  SS, Homa  DM, Wang  T,  et al.  State-specific patterns of cigarette smoking, smokeless tobacco use, and e-cigarette use among adults: United States, 2016.  Prev Chronic Dis. 2019;16:E17. doi:10.5888/pcd16.180362PubMedGoogle Scholar
36.
Centers for Disease Control and Prevention. Behavioral Risk Factor Surveillance System. https://www.cdc.gov/brfss/. Accessed February 1, 2019.
37.
von Elm  E, Altman  DG, Egger  M, Pocock  SJ, Gøtzsche  PC, Vandenbroucke  JP; STROBE Initiative.  The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies.  J Clin Epidemiol. 2008;61(4):344-349. doi:10.1016/j.jclinepi.2007.11.008PubMedGoogle ScholarCrossref
38.
Iachan  R, Pierannunzi  C, Healey  K, Greenlund  KJ, Town  M.  National weighting of data from the Behavioral Risk Factor Surveillance System (BRFSS).  BMC Med Res Methodol. 2016;16(1):155. doi:10.1186/s12874-016-0255-7PubMedGoogle ScholarCrossref
39.
Chaloupka  FJ, Straif  K, Leon  ME; Working Group, International Agency for Research on Cancer.  Effectiveness of tax and price policies in tobacco control.  Tob Control. 2011;20(3):235-238. doi:10.1136/tc.2010.039982PubMedGoogle ScholarCrossref
40.
Chaloupka  FJ, Yurekli  A, Fong  GT.  Tobacco taxes as a tobacco control strategy.  Tob Control. 2012;21(2):172-180. doi:10.1136/tobaccocontrol-2011-050417PubMedGoogle ScholarCrossref
41.
Hoffman  SJ, Tan  C.  Overview of systematic reviews on the health-related effects of government tobacco control policies.  BMC Public Health. 2015;15:744. doi:10.1186/s12889-015-2041-6PubMedGoogle ScholarCrossref
42.
Astor  RL, Urman  R, Barrington-Trimis  JL,  et al.  Tobacco retail licensing and youth product use.  Pediatrics. 2019;143(2):e20173536. doi:10.1542/peds.2017-3536PubMedGoogle Scholar
43.
Benmarhnia  T, Pierce  JP, Leas  E,  et al.  Can e-cigarettes and pharmaceutical aids increase smoking cessation and reduce cigarette consumption? findings from a nationally representative cohort of American smokers.  Am J Epidemiol. 2018;187(11):2397-2404. doi:10.1093/aje/kwy129PubMedGoogle ScholarCrossref
44.
Barrington-Trimis  JL, Urman  R, Berhane  K,  et al.  E-Cigarettes and future cigarette use.  Pediatrics. 2016;138(1):e20160379. doi:10.1542/peds.2016-0379PubMedGoogle Scholar
45.
Berry  KM, Fetterman  JL, Benjamin  EJ,  et al.  Association of electronic cigarette use with subsequent initiation of tobacco cigarettes in US youths.  JAMA Netw Open. 2019;2(2):e187794. doi:10.1001/jamanetworkopen.2018.7794PubMedGoogle Scholar
46.
Chapman  S, Bareham  D, Maziak  W.  The gateway effect of e-cigarettes: reflections on main criticisms.  Nicotine Tob Res. 2019;21(5):695-698. doi:10.1093/ntr/nty067PubMedGoogle ScholarCrossref
47.
Kandel  ER, Kandel  DB.  A molecular basis for nicotine as a gateway drug.  N Engl J Med. 2014;371(10):932-943. doi:10.1056/NEJMsa1405092PubMedGoogle ScholarCrossref
48.
Etter  JF.  Gateway effects and electronic cigarettes.  Addiction. 2018;113(10):1776-1783. doi:10.1111/add.13924PubMedGoogle ScholarCrossref
49.
Lee  PN, Coombs  KJ, Afolalu  EF.  Considerations related to vaping as a possible gateway into cigarette smoking: an analytical review.  F1000Res. 2018;7:1915. doi:10.12688/f1000research.16928.1PubMedGoogle ScholarCrossref
50.
Avino  P, Scungio  M, Stabile  L, Cortellessa  G, Buonanno  G, Manigrasso  M.  Second-hand aerosol from tobacco and electronic cigarettes: evaluation of the smoker emission rates and doses and lung cancer risk of passive smokers and vapers.  Sci Total Environ. 2018;642:137-147. doi:10.1016/j.scitotenv.2018.06.059PubMedGoogle ScholarCrossref
51.
Visser  WF, Klerx  WN, Cremers  HWJM, Ramlal  R, Schwillens  PL, Talhout  R.  The health risks of electronic cigarette use to bystanders.  Int J Environ Res Public Health. 2019;16(9):E1525. doi:10.3390/ijerph16091525PubMedGoogle Scholar
52.
Bals  R, Boyd  J, Esposito  S,  et al.  Electronic cigarettes: a task force report from the European Respiratory Society.  Eur Respir J. 2019;53(2):1801151. doi:10.1183/13993003.01151-2018PubMedGoogle Scholar
53.
Gentzke  AS, Creamer  M, Cullen  KA,  et al.  Vital signs: tobacco product use among middle and high school students—United States, 2011-2018.  MMWR Morb Mortal Wkly Rep. 2019;68(6):157-164. doi:10.15585/mmwr.mm6806e1PubMedGoogle ScholarCrossref
54.
US Department of Health and Human Services; Public Health Service; Office of the Surgeon General.  E-Cigarette Use Among Youth and Young Adults: A Report of the Surgeon General. Rockville, MD: US Department of Health and Human Services; 2016.
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    1 Comment for this article
    Next study to look at
    Christina Tansy, MS, MMS, PA-C |
    Regulations may reduce e-cig use but is there an increase in people going back to combustible cigarette use? As bad as either product is, I feel there is a small mitigation of risk with the e-cigs as long as people are not using “street juice,” which is the substance that has been linked to the e-cig related deaths. Vitamin E, or any other oil, is not good for the lungs when inhaled. I believe, the CDC has linked Vit E containing street juice to most of the e-cig deaths.
    Also, a better age breakdown would be helpful.
    CONFLICT OF INTEREST: None Reported
    Original Investigation
    Public Health
    January 31, 2020

    Association of Electronic Cigarette Regulations With Electronic Cigarette Use Among Adults in the United States

    Author Affiliations
    • 1Department of Epidemiology, University of Iowa College of Public Health, Iowa City
    JAMA Netw Open. 2020;3(1):e1920255. doi:10.1001/jamanetworkopen.2019.20255
    Key Points español 中文 (chinese)

    Question  Are US state regulations regarding electronic cigarettes (e-cigarettes) associated with current e-cigarette use among US adults?

    Findings  This cross-sectional study used national data from 894 997 participants aged 18 years or older from the 2016 and 2017 Behavioral Risk Factor Surveillance System surveys. State regulations prohibiting e-cigarette use in indoor areas, requiring retailers to purchase a license to sell e-cigarettes, prohibiting sales of tobacco products to persons younger than 21 years, and applying taxes to e-cigarettes were associated with a lower prevalence of current e-cigarette use among US adults.

    Meaning  Several state regulations regarding e-cigarettes may be associated with reduced current e-cigarette use among US adults.

    Abstract

    Importance  Millions of Americans use electronic cigarettes (e-cigarettes). A growing number of state and local governments have started to draft and implement laws regarding the sale, marketing, and use of e-cigarettes. The association of US state regulations regarding e-cigarettes with e-cigarette use remains unknown.

    Objective  To examine the association of US state regulations regarding e-cigarettes with current e-cigarette use among adults in the United States.

    Design, Setting, and Participants  This cross-sectional study included adults aged 18 years or older from the 2016 and 2017 Behavioral Risk Factor Surveillance System, which is a nationwide, telephone-administered survey that collects state-representative data on health-related risk behaviors, chronic health conditions, and use of preventive services. Data analysis was performed from February 1, 2019, to April 31, 2019.

    Exposures  United States state laws regulating e-cigarette use, including prohibiting e-cigarette use in indoor areas of private workplaces, restaurants, and bars; requiring retailers to purchase a license to sell e-cigarettes; prohibiting self-service displays of e-cigarettes; prohibiting sales of tobacco products, including e-cigarettes, to persons younger than 21 years; and e-cigarette taxes.

    Main Outcomes and Measures  Current use of e-cigarettes.

    Results  Among 894 997 participants aged 18 years or older (503 688 women [51.3%], 679 443 non-Hispanic white [62.6%], 71 730 non-Hispanic black [16.3%], 69 823 Hispanic [11.4%], and 74 001 non-Hispanic other races [9.8%]), 28 907 (weighted prevalence, 4.4%) were currently using e-cigarettes. The age-standardized weighted prevalence of current e-cigarette use varied across US states and territories, from 1.0% in Puerto Rico to 6.2% in Guam. After adjustment for demographic, socioeconomic, and lifestyle factors, including conventional cigarette use, the odds ratios of current e-cigarette use were 0.90 (95% CI, 0.83-0.98) for state laws prohibiting e-cigarette use in indoor areas of private workplaces, restaurants, and bars; 0.90 (95% CI, 0.85-0.95) for state laws requiring retailers to purchase a license to sell e-cigarettes; 1.04 (95% CI, 0.99-1.09) for state laws prohibiting self-service displays of e-cigarettes; 0.86 (95% CI, 0.74-0.99) for state laws prohibiting sales of tobacco products, including e-cigarettes, to persons younger than 21 years; and 0.89 (95% CI, 0.83-0.96) for state laws applying taxes to e-cigarettes.

    Conclusions and Relevance  These findings suggest that several state regulations regarding e-cigarettes may be associated with reduced e-cigarette use among US adults.

    Introduction

    Electronic cigarettes (e-cigarettes) have been marketed as a safer alternative to conventional cigarettes and an adjunct for smoking cessation.1-3 Millions of US individuals use e-cigarettes.4Moreover, although the prevalence of conventional cigarette smoking is declining,5 e-cigarette use has become more popular in the US population.6,7 In the United States, 3.2% of adults currently used e-cigarettes in 2018, and the rate was even higher among young adults aged 18 to 24 years, with a current use rate of 7.6%.8 Thus far, evidence regarding the efficacy and safety of e-cigarettes for successful smoking cessation is controversial and inconclusive.2,9-16 A limited number of clinical trials13,14,16 on the use of e-cigarettes for smoking cessation have been published, and the results are conflicting. Moreover, initial use of e-cigarettes may increase the risk of subsequent conventional cigarette smoking among youth and young adults.17 In addition, although e-cigarettes generally contain fewer numbers and lower levels of harmful substances (eg, nicotine) than combustible tobacco cigarettes,18-20 most e-cigarettes contain and emit numerous other substances that are potentially toxic, such as heavy metals, propylene glycol, volatile organic chemicals, and carcinogenic agents.21,22 More than 7000 flavoring chemicals, many with uncertain toxicity, are currently marketed for e-cigarettes.23 Recent studies have shown that the use of e-cigarettes is associated with endothelial cell dysfunction, oxidative stress, impaired vascular function,24-26 increased risk of cardiovascular diseases,27-29 and other long-term adverse health outcomes.30

    In May 2016, the US Food and Drug Administration released a rule31 to regulate the manufacturing, distribution, and marketing of e-cigarettes as a tobacco product. In addition, state, local, tribal, and territorial governments maintain broad regulatory authority and have taken additional, more-stringent actions.32 Since 2010, a growing number of states and local governments have started to draft and implement laws regarding the sale, marketing, and use of e-cigarettes.33 Currently, e-cigarette–related regulations and policies implemented by some US states include laws prohibiting e-cigarette use in indoor areas of private workplaces, restaurants, and bars; laws requiring retailers to purchase a license to sell e-cigarettes; laws prohibiting self-service displays of e-cigarettes; laws prohibiting sales of tobacco products, including e-cigarettes, to persons younger than 21 years; and laws applying taxes to e-cigarettes.33 Some states have adopted multiple laws, whereas others have not.32,33 Previous studies4,34,35 have found substantial variations in the prevalence of current e-cigarette use among adults across US states; however, the association of state laws regarding e-cigarettes with e-cigarette use is still unknown.

    In this cross-sectional study using data from a large nationwide surveillance program covering all 50 states and participating territories in the United States, we examined the association of US state regulations regarding e-cigarettes with current e-cigarette use among adults in the United States. We hypothesized that state laws regarding e-cigarettes may be associated with lower prevalence of e-cigarette use among adults across US states.

    Methods
    Study Population

    The Behavioral Risk Factor Surveillance System (BRFSS) is the premier system of health-related telephone surveys in the United States. The BRFSS collects data from US residents in all 50 states, the District of Columbia, and 3 US territories (Puerto Rico, Guam, and US Virgin Islands) regarding their health-related risk behaviors, chronic health conditions, and use of preventive services. The BRFSS completes more than 400 000 adult interviews each year, making it the largest continuously conducted health survey system in the world. With technical and methodological assistance from the Centers for Disease Control and Prevention (CDC), state health departments use in-house interviewers or contract with telephone call centers or universities to administer the BRFSS surveys continuously through the year. In the BRFSS, a sample record is 1 telephone number in the list of all telephone numbers the system randomly selects for dialing. The survey is conducted using random digit dialing techniques on both landlines and cellular telephones. Each state samples from adults living in private residences via landline and cellular telephone. A disproportionate stratified sampling design is usually used in the landline sample, which requires interviewers to collect information on the number of adults living within a residence and then select randomly from all eligible adults. Cellular telephone sampling frames are commercially available, and the system can call random samples of cellular telephone numbers, according to specific protocols. A detailed description of the BRFSS survey design, questionnaires, and data collection can be found on the BRFSS website.36

    The BRFSS is unique because it is designed to be state representative, which allows estimation of state-level e-cigarette use among the general population in the United States. We used data from the BRFSS 2016 and 2017 surveys, because the BRFSS first started to collect information on e-cigarette use in 2016. During 2016, all 50 states, the District of Columbia, the Commonwealth of Puerto Rico, Guam, and US Virgin Islands collected BRFSS data, whereas during 2017, US Virgin Islands did not collect BRFSS data; thus, we did not include US Virgin Islands in the present analysis. The term “state” is used to refer to all areas participating in the BRFSS, including the District of Columbia, Guam, and the Commonwealth of Puerto Rico.

    The University of Iowa institutional review board determined that the present study is exempt from the need to obtain informed consent because of the use of deidentified data. This study follows the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guidelines.37

    Assessment of e-Cigarette Use

    Participants were asked about their history of cigarette smoking and e-cigarette use. For e-cigarettes, the BRFSS questionnaire included a brief introduction, as follows: “Electronic cigarettes (e-cigarettes) and other electronic ‘vaping’ products include electronic hookahs (e-hookahs), vape pens, e-cigars, and others. These products are battery-powered and usually contain nicotine and flavors such as fruit, mint, or candy.” Participants were first asked, “Have you ever used an e-cigarette or other electronic ‘vaping’ product, even just one time, in your entire life?” Those who responded yes were further asked, “Do you now use e-cigarettes or other electronic ‘vaping’ products every day, some days, or not at all?” Similar to previous studies,4,7 we considered participants who answered yes to the first question and then responded either “every day” or “some days” to the second question as current users of e-cigarettes. In this study, we focused on current use of e-cigarettes.

    Ascertainment of State Laws Regarding e-Cigarettes

    For each type of state law, we considered participants as being exposed to the state law if they were living in the state where the state law regarding e-cigarette use was implemented no later than January 1 of the survey year. Information about whether and when state laws regarding e-cigarettes were implemented was derived for all the 50 states, the District of Columbia, Puerto Rico, and Guam according to the CDC State Tobacco Activities Tracking and Evaluation System.33 Consistent with a recent report by the CDC,33 US states were classified according to whether the state has implemented each type of the following state laws: prohibiting e-cigarette use in indoor areas of private workplaces, restaurants, and bars; requiring retailers to purchase a license to sell e-cigarettes; prohibiting self-service displays of e-cigarettes; prohibiting sales of tobacco products, including e-cigarettes, to persons younger than 21 years; and e-cigarette taxes. Because we included 2 years of data from BRFSS, we linked state laws to each participant according to the year the survey was completed. For example, participants in the 2016 survey were regarded as being exposed to the laws if the states where they were living implemented the specific laws no later than January 1, 2016. Similarly, for participants in the 2017 survey, if the states where they were living implemented the specific laws no later than January 1, 2017, they were regarded as being exposed to the laws.

    Assessment of Covariates

    Information on participants’ age, gender, race/ethnicity, education, family income, cigarette smoking, alcohol drinking, and physical activity was collected during the interview. Race/ethnicity was categorized as non-Hispanic white, non-Hispanic black, Hispanic (Mexican and non-Mexican Hispanic), and other race/ethnicity. Education was grouped as less than high school, high school, attended college, or graduated from college. Annual family income was categorized as less than $15 000, $15 000 to less than $25 000, $25 000 to less than $35 000, $35 000 to less than $50 000, and $50 000 or more. Current alcohol intake was categorized as none (0 drinks per week), moderate drinking (1-14 drinks per week for men and 1-7 drinks per week for women), and heavy drinking (>14 drinks per week for men and >7 drinks per week for women). Participants were categorized as nonsmokers, former smokers, current smokers some days, and current smokers every day. Physical activity was categorized according to whether the participant had engaged in leisure time physical activity during the past 30 days other than at their regular job.

    Statistical Analysis

    We incorporated survey sampling weights, provided by the CDC along with the BRFSS data set, in all analyses to account for the complex survey design and to make the findings generalizable to the general population at both the state and national level. Since 2011, the BRFSS has used a technique called “raking” to weight BRFSS survey data to account for known proportions of age, race/ethnicity, gender, geographic region, and other socioeconomic characteristics such as education level and home ownership status of participants. A detailed description of the weighting processes in BRFSS has been published elsewhere.38

    Characteristics of the study participants are presented as means (standard errors) for continuous variables or counts (percentage) for categorical variables. Generalized linear models were used to compare differences in continuous variables, and χ2 tests were used for categorical variables. We calculated the age-standardized prevalence of current e-cigarette use according to 2010 US Census population data using age categories of 18 to 44 years, 45 to 64 years, and 65 years or older. We calculated the difference in prevalence of e-cigarette use in each state between 2016 and 2017. We used multivariable logistic regression models to estimate odds ratios and 95% CIs of current e-cigarette use associated with state laws regarding e-cigarettes. Model 1 was adjusted for age and gender. Model 2 was further adjusted for race/ethnicity, education, family income, smoking status, alcohol intake, and physical activity. We conducted stratified analyses according to age (18-24, 25-44, 45-64, and ≥65 years), gender (male vs female), race/ethnicity (white vs nonwhite), education level (high school or less vs more than high school), annual family income (<$50 000 vs ≥$50 000), and smoking status (current smoker every day, current smoker some days, former smoker, or never smoker). Interaction analyses were performed by including multiplicative terms of each exposure variable with effect modifier variable in the aforementioned multivariable models.

    All analyses were performed using survey procedures in SAS statistical software version 9.4 (SAS Institute). Two-sided P < .05 was considered statistically significant. Data analysis was performed from February 1, 2019, to April 31, 2019.

    Results

    In this study, we included 894 997 adults aged 18 years or older with data on state residence and e-cigarette use available (503 688 women [51.3%], 679 443 non-Hispanic white [62.6%], 71 730 non-Hispanic black [16.3%], 69 823 Hispanic [11.4%], and 74 001 non-Hispanic other races [9.8%]); 28 907 participants (weighted prevalence, 4.4%) were currently using e-cigarettes. Electronic cigarette users were more likely than nonusers to be male (15 068 [60.1%] vs 375 940 [48.1%]; difference, 12.0%; 95% CI, 11.4%-12.6%; P < .001), non-Hispanic white (22 174 [70.6%] vs 657 269 [62.2%]; difference, 8.4%; 95% CI, 7.8%-9.0%; P < .001), current smokers (15 982 [51.5%] vs 115 125 [14.6%]; difference, 36.9%; 95% CI, 36.1%-37.7%; P < .001), and alcohol drinkers (16 382 [60.9%] vs 432 113 [51.3%]; difference, 9.6%; 95% CI, 8.9%-10.3%; P < .001) (Table 1). The age-standardized weighted prevalence of current e-cigarette use varied across US states and territories, from 1.0% in Puerto Rico to 6.2% in Guam (Figure). From 2016 to 2017, although the weighted prevalence of current e-cigarette use in several states slightly increased, more states had a decreased or unchanged prevalence of current e-cigarette use (eFigure in the Supplement).

    Across the types of state laws pertaining to e-cigarette use, the most commonly implemented laws were those prohibiting self-service displays of e-cigarettes, followed by those requiring a retail license to sell e-cigarettes and those banning the use of e-cigarettes and conventional cigarettes in restaurants, bars, and workplaces. As of January 1, 2017, only 7 states (District of Columbia, Kansas, Louisiana, Minnesota, North Carolina, Pennsylvania, and West Virginia) applied an excise tax to e-cigarettes, and only 3 states (California, District of Columbia, Hawaii) set 21 years as the minimum age to purchase e-cigarettes (Table 2). For each subtype of state laws regarding e-cigarettes, there was an increase in the number of states that implemented new state laws from 2016 to 2017.

    We observed associations of several state laws regarding e-cigarettes with e-cigarette use. After adjustment for age, gender, race/ethnicity, education, family income, smoking status, alcohol intake, and physical activity, the odds ratios of current e-cigarette use associated with state-level regulations and policies were 0.90 (95% CI, 0.83-0.98) for state laws prohibiting e-cigarette use in indoor areas of private workplaces, restaurants, and bars; 0.90 (95% CI, 0.85-0.95) for state laws requiring retailers to purchase a license to sell e-cigarettes; 1.04 (95% CI, 0.99-1.09) for state laws prohibiting self-service displays of e-cigarettes; 0.86 (95% CI, 0.74-0.99) for state laws prohibiting sales of tobacco products, including e-cigarettes, to persons younger than 21 years; and 0.89 (95% CI, 0.83-0.96) for state laws applying taxes to e-cigarettes (Table 3).

    In stratified analyses, there was an association between state laws regarding e-cigarettes and e-cigarette use among adults aged 45 to 64 years, female participants, nonwhite participants, those with lower education levels, and those with lower family income (eTable in the Supplement). For example, the odds ratios of current e-cigarette use associated with state laws prohibiting e-cigarette use in indoor areas of private workplaces, restaurants, and bars were 0.95 (95% CI, 0.81-1.12) for adults aged 18 to 24 years, 1.00 (95% CI, 0.88-1.13) for adults aged 25 to 44 years, 0.68 (95% CI, 0.59-0.79) for adults aged 45 to 64 years, and 0.82 (95% CI, 0.62-1.10) for adults aged 65 years or older (eTable in the Supplement). However, for e-cigarette taxes, there was an association with e-cigarette use among adults aged 18 to 24 years and those 65 years and older. The odds ratios of current e-cigarette use associated with state laws applying taxes to e-cigarettes were 0.81 (95% CI, 0.68-0.97) for adults aged 18 to 24 years, 0.93 (95% CI, 0.83-1.04) for adults aged 25 to 44 years, 0.96 (95% CI, 0.85-1.09) for adults aged 45 to 64 years, and 0.78 (95% CI, 0.62-0.98) for adults aged 65 years or older (eTable in the Supplement).

    Discussion

    In a large, nationwide, state-based heath survey of US adults, we found associations of e-cigarette use with state laws that prohibit e-cigarette use in indoor areas of private workplaces, restaurants, and bars; that require a retail license to sell e-cigarettes; that prohibit sales of tobacco products, including e-cigarettes, to persons younger than 21 years; and that apply taxes to e-cigarettes. To our knowledge, this is the first study estimating the potential outcomes of state laws on e-cigarette use among US adults. Consistent with previous reports,4,34,35 our findings show that the age-standardized prevalence of current e-cigarette use varied across states. The reasons for the state variations remain to be elucidated, but these findings provide clues about the potential outcomes associated with e-cigarette laws. At the state level, a CDC report33 documented that the legislative activity regarding e-cigarettes was initiated in 2010, increased between 2013 and 2015, and peaked in 2015. One recent study7 found a substantial decrease in current e-cigarette use among US adults between 2014 and 2016, which may indicate a positive outcome of state laws to curb the increasing trend of e-cigarette use.

    Taxation and smoke-free laws (ie, prohibiting cigarette smoking in restaurants, bars, and workplaces) have been proven to help increase smoking cessation and reduce the prevalence of conventional cigarette use in the US general population.39-41 It is interesting and reassuring that e-cigarette–related regulations similar to the aforementioned laws may also help reduce e-cigarette use. We also observed an association of retail license requirements with a lower rate of e-cigarette use in adults. The retail license requirement as a strategy to regulate e-cigarettes has aroused public attention, because a recent study42 found that youth who live in areas with strong tobacco vendor licensing requirements have lower rates of tobacco use and e-cigarette use. However, federal law does not require retailers to have a license to sell e-cigarettes,31 and fewer than one-third of states require e-cigarette retailers to be licensed. Before January 1, 2017, only Hawaii, California, and the District of Columbia implemented laws prohibiting sales of e-cigarettes to persons younger than 21 years (also known as “tobacco 21 laws”).32 Therefore, further studies are needed to evaluate the association between implementation of the tobacco 21 laws and e-cigarette use among adolescents and young adults in the United States.

    Our study has public health implications. e-Cigarette use has emerged as a major public health issue. Millions of adults and youth in the United States are using e-cigarettes.5 e-Cigarettes may aid in smoking cessation for some individuals, but they may also cause harm to others.1 At the time e-cigarettes entered the US market, they were commonly regarded as a safer substitute for conventional cigarettes, and many smokers initiated e-cigarette use with an intention to quit smoking.3 Our results show that more than one-half (51.5%) of current e-cigarette users are also current conventional cigarette smokers. Despite their popularity, e-cigarettes have not been approved by the US Food and Drug Administration for smoking cessation, and the efficacy and safety of e-cigarettes compared with US Food and Drug Administration–approved cessation aids warrant further investigation.15,16,43

    Moreover, e-cigarette use might be associated with youth or never smokers transitioning to combustible tobacco products.17,44-46 Whether e-cigarette use is a possible gateway to the use of combustible cigarettes and other substances (eg, alcohol or illegal drugs) remains to be determined.46-49 Widespread use of e-cigarettes can also lead to secondhand exposure to nicotine and other toxic substances from e-cigarettes.50-52 Therefore, careful consideration of the potential benefits and harms of e-cigarettes is needed in determining the net public health consequences associated with use of e-cigarettes.

    In addition to e-cigarette regulations at the federal level by the US Food and Drug Administration, state and local regulations and policies regarding e-cigarettes can help reduce the public health risks associated with e-cigarettes, particularly among at-risk populations.33 Recent studies8,53 have reported an emerging increase in the prevalence of current e-cigarette use among US youth and young adults aged 18 to 24 years. This increase is concerning because nicotine exposure from e-cigarettes may harm brain development in young people.54 Our stratified analyses showed that among adults aged 18 to 24 years, e-cigarette taxes were associated with lower rates of e-cigarette use. Although the reasons for this association remain unclear and warrant further investigation, it indicates that state-level regulations may be a hopeful approach to curb the increase in e-cigarette use among young adults.

    Strengths and Limitations

    The major strength of our study is the use of data from a nationwide, state-based, large-scale health survey of US adults. Because of the special considerations for both nationwide and state-level sampling during survey design, BRFSS is uniquely positioned to address state variations and determinants of health behaviors, including e-cigarette use. There are also several limitations to this study. First, the information on e-cigarette use and other lifestyle factors (eg, cigarette smoking and alcohol drinking) were collected via self-reports, which may be subject to misreporting or recall bias. Second, we did not have information on the brands and subtypes of e-cigarettes and types of e-cigarette liquid. Whether the state laws would have differential associations with the different subtypes of e-cigarettes warrants further investigation. Third, participants were regarded as being exposed to the e-cigarette–related state laws in the specific state where they resided at the time of the BRFSS survey. It is possible that some participants moved or worked between states, which may have resulted in misclassification of the exposure to state laws. Fourth, although we have adjusted for a variety of covariates related to both state laws and e-cigarette use, the BRFSS did not collect detailed information on the years that participants resided in the same states and participants’ knowledge of the state laws regarding e-cigarette. Therefore, residual confounding may still exist.

    Conclusions

    Findings from this study suggest that US state regulations regarding e-cigarettes may be associated with reduced e-cigarette use among US adults. Because of the dynamic nature of state law legislation and implementation, future studies are needed to continue monitoring the patterns of state-level variations in e-cigarette use and the outcomes of changing state laws on e-cigarette use.

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    Article Information

    Accepted for Publication: December 4, 2019.

    Published: January 31, 2020. doi:10.1001/jamanetworkopen.2019.20255

    Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2020 Du Y et al. JAMA Network Open.

    Corresponding Author: Wei Bao, MD, PhD, Department of Epidemiology, University of Iowa College of Public Health, 145 N Riverside Dr, CPHB, Room S431, Iowa City, IA 52242 (wei-bao@uiowa.edu).

    Author Contributions: Dr Bao had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

    Concept and design: Snetselaar, Wallace, Bao.

    Acquisition, analysis, or interpretation of data: Du, Liu, Xu, Rong, Sun, Wu, Snetselaar, Bao.

    Drafting of the manuscript: Du, Wallace.

    Critical revision of the manuscript for important intellectual content: Du, Liu, Xu, Rong, Sun, Wu, Snetselaar, Bao.

    Statistical analysis: Du, Rong, Sun, Snetselaar.

    Administrative, technical, or material support: Wu, Snetselaar, Bao.

    Supervision: Snetselaar, Wallace, Bao.

    Conflict of Interest Disclosures: None reported.

    Funding/Support: This research was supported in part by award P30 ES005605 from the National Institutes of Health.

    Role of the Funder/Sponsor: The funder had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

    References
    1.
    National Academies of Sciences Engineering and Medicine.  Public Health Consequences of E-Cigarettes. Washington, DC: National Academies Press; 2018.
    2.
    Dinakar  C, O’Connor  GT.  The health effects of electronic cigarettes.  N Engl J Med. 2016;375(14):1372-1381. doi:10.1056/NEJMra1502466PubMedGoogle ScholarCrossref
    3.
    Grana  R, Benowitz  N, Glantz  SA.  E-cigarettes: a scientific review.  Circulation. 2014;129(19):1972-1986. doi:10.1161/CIRCULATIONAHA.114.007667PubMedGoogle ScholarCrossref
    4.
    Mirbolouk  M, Charkhchi  P, Kianoush  S,  et al.  Prevalence and distribution of e-cigarette use among U.S. adults: Behavioral Risk Factor Surveillance System, 2016.  Ann Intern Med. 2018;169(7):429-438. doi:10.7326/M17-3440PubMedGoogle ScholarCrossref
    5.
    Jamal  A, King  BA, Neff  LJ, Whitmill  J, Babb  SD, Graffunder  CM.  Current cigarette smoking among adults: United States, 2005-2015.  MMWR Morb Mortal Wkly Rep. 2016;65(44):1205-1211. doi:10.15585/mmwr.mm6544a2PubMedGoogle ScholarCrossref
    6.
    McMillen  RC, Gottlieb  MA, Shaefer  RM, Winickoff  JP, Klein  JD.  Trends in electronic cigarette use among U.S. adults: use is increasing in both smokers and nonsmokers.  Nicotine Tob Res. 2015;17(10):1195-1202. doi:10.1093/ntr/ntu213PubMedGoogle ScholarCrossref
    7.
    Bao  W, Xu  G, Lu  J, Snetselaar  LG, Wallace  RB.  Changes in electronic cigarette use among adults in the United States, 2014-2016.  JAMA. 2018;319(19):2039-2041. doi:10.1001/jama.2018.4658PubMedGoogle ScholarCrossref
    8.
    Bao  W, Liu  B, Du  Y, Snetselaar  LG, Wallace  RB.  Electronic cigarette use among young, middle-aged, and older adults in the United States in 2017 and 2018  [published online October 14, 2019].  JAMA Intern Med. doi:10.1001/jamainternmed.2019.4957PubMedGoogle Scholar
    9.
    Yeh  JS, Bullen  C, Glantz  SA.  E-Cigarettes and smoking cessation.  N Engl J Med. 2016;374(22):2172-2174. doi:10.1056/NEJMclde1602420PubMedGoogle ScholarCrossref
    10.
    Hartmann-Boyce  J, Begh  R, Aveyard  P.  Electronic cigarettes for smoking cessation.  BMJ. 2018;360:j5543. doi:10.1136/bmj.j5543PubMedGoogle ScholarCrossref
    11.
    Kalkhoran  S, Glantz  SA.  E-cigarettes and smoking cessation in real-world and clinical settings: a systematic review and meta-analysis.  Lancet Respir Med. 2016;4(2):116-128. doi:10.1016/S2213-2600(15)00521-4PubMedGoogle ScholarCrossref
    12.
    McRobbie  H, Bullen  C, Hartmann-Boyce  J, Hajek  P.  Electronic cigarettes for smoking cessation and reduction.  Cochrane Database Syst Rev. 2014;(12):CD010216. doi:10.1002/14651858.CD010216.pub2PubMedGoogle Scholar
    13.
    Bullen  C, Howe  C, Laugesen  M,  et al.  Electronic cigarettes for smoking cessation: a randomised controlled trial.  Lancet. 2013;382(9905):1629-1637. doi:10.1016/S0140-6736(13)61842-5PubMedGoogle ScholarCrossref
    14.
    Halpern  SD, Harhay  MO, Saulsgiver  K, Brophy  C, Troxel  AB, Volpp  KG.  A pragmatic trial of e-cigarettes, incentives, and drugs for smoking cessation.  N Engl J Med. 2018;378(24):2302-2310. doi:10.1056/NEJMsa1715757PubMedGoogle ScholarCrossref
    15.
    Borrelli  B, O’Connor  GT.  E-Cigarettes to assist with smoking cessation.  N Engl J Med. 2019;380(7):678-679. doi:10.1056/NEJMe1816406PubMedGoogle ScholarCrossref
    16.
    Hajek  P, Phillips-Waller  A, Przulj  D,  et al.  A randomized trial of e-cigarettes versus nicotine-replacement therapy.  N Engl J Med. 2019;380(7):629-637. doi:10.1056/NEJMoa1808779PubMedGoogle ScholarCrossref
    17.
    Soneji  S, Barrington-Trimis  JL, Wills  TA,  et al.  Association between initial use of e-cigarettes and subsequent cigarette smoking among adolescents and young adults: a systematic review and meta-analysis.  JAMA Pediatr. 2017;171(8):788-797. doi:10.1001/jamapediatrics.2017.1488PubMedGoogle ScholarCrossref
    18.
    Goniewicz  ML, Knysak  J, Gawron  M,  et al.  Levels of selected carcinogens and toxicants in vapour from electronic cigarettes.  Tob Control. 2014;23(2):133-139. doi:10.1136/tobaccocontrol-2012-050859PubMedGoogle ScholarCrossref
    19.
    Goniewicz  ML, Kuma  T, Gawron  M, Knysak  J, Kosmider  L.  Nicotine levels in electronic cigarettes.  Nicotine Tob Res. 2013;15(1):158-166. doi:10.1093/ntr/nts103PubMedGoogle ScholarCrossref
    20.
    Goniewicz  ML, Smith  DM, Edwards  KC,  et al.  Comparison of nicotine and toxicant exposure in users of electronic cigarettes and combustible cigarettes.  JAMA Netw Open. 2018;1(8):e185937. doi:10.1001/jamanetworkopen.2018.5937PubMedGoogle Scholar
    21.
    Hess  CA, Olmedo  P, Navas-Acien  A, Goessler  W, Cohen  JE, Rule  AM.  E-cigarettes as a source of toxic and potentially carcinogenic metals.  Environ Res. 2017;152:221-225. doi:10.1016/j.envres.2016.09.026PubMedGoogle ScholarCrossref
    22.
    Rubinstein  ML, Delucchi  K, Benowitz  NL, Ramo  DE.  Adolescent exposure to toxic volatile organic chemicals from e-cigarettes.  Pediatrics. 2018;141(4):e20173557. doi:10.1542/peds.2017-3557PubMedGoogle Scholar
    23.
    Allen  JG, Flanigan  SS, LeBlanc  M,  et al.  Flavoring chemicals in e-cigarettes: diacetyl, 2,3-pentanedione, and acetoin in a sample of 51 products, including fruit-, candy-, and cocktail-flavored e-cigarettes.  Environ Health Perspect. 2016;124(6):733-739. doi:10.1289/ehp.1510185PubMedGoogle ScholarCrossref
    24.
    Moheimani  RS, Bhetraratana  M, Yin  F,  et al.  Increased cardiac sympathetic activity and oxidative stress in habitual electronic cigarette users: implications for cardiovascular risk.  JAMA Cardiol. 2017;2(3):278-284. doi:10.1001/jamacardio.2016.5303PubMedGoogle ScholarCrossref
    25.
    Muthumalage  T, Prinz  M, Ansah  KO, Gerloff  J, Sundar  IK, Rahman  I.  Inflammatory and oxidative responses induced by exposure to commonly used e-cigarette flavoring chemicals and flavored e-liquids without nicotine.  Front Physiol. 2018;8:1130. doi:10.3389/fphys.2017.01130PubMedGoogle ScholarCrossref
    26.
    Carnevale  R, Sciarretta  S, Violi  F,  et al.  Acute impact of tobacco vs electronic cigarette smoking on oxidative stress and vascular function.  Chest. 2016;150(3):606-612. doi:10.1016/j.chest.2016.04.012PubMedGoogle ScholarCrossref
    27.
    Alzahrani  T, Pena  I, Temesgen  N, Glantz  SA.  Association between electronic cigarette use and myocardial infarction.  Am J Prev Med. 2018;55(4):455-461. doi:10.1016/j.amepre.2018.05.004PubMedGoogle ScholarCrossref
    28.
    Yan  XS, D’Ruiz  C.  Effects of using electronic cigarettes on nicotine delivery and cardiovascular function in comparison with regular cigarettes.  Regul Toxicol Pharmacol. 2015;71(1):24-34. doi:10.1016/j.yrtph.2014.11.004PubMedGoogle ScholarCrossref
    29.
    Vlachopoulos  C, Ioakeimidis  N, Abdelrasoul  M,  et al.  Electronic cigarette smoking increases aortic stiffness and blood pressure in young smokers.  J Am Coll Cardiol. 2016;67(23):2802-2803. doi:10.1016/j.jacc.2016.03.569PubMedGoogle ScholarCrossref
    30.
    Kalkhoran  S, Glantz  SA.  Modeling the health effects of expanding e-cigarette sales in the United States and United Kingdom: a Monte Carlo analysis.  JAMA Intern Med. 2015;175(10):1671-1680. doi:10.1001/jamainternmed.2015.4209PubMedGoogle ScholarCrossref
    31.
    US Food and Drug Administration, Department of Health and Human Services.  Deeming tobacco products to be subject to the Federal Food, Drug, and Cosmetic Act, as amended by the Family Smoking Prevention and Tobacco Control Act: restrictions on the sale and distribution of tobacco products and required warning statements for tobacco products—final rule.  Fed Regist. 2016;81(90):28973-29106.PubMedGoogle Scholar
    32.
    Public Health Law Center.  U.S. E-Cigarette Regulation: A 50-State Review. St Paul, MN: Tobacco Control Legal Consortium; 2018.
    33.
    Marynak  K, Kenemer  B, King  BA, Tynan  MA, MacNeil  A, Reimels  E.  State laws regarding indoor public use, retail sales, and prices of electronic cigarettes: U.S. states, Guam, Puerto Rico, and U.S. Virgin Islands, September 30, 2017.  MMWR Morb Mortal Wkly Rep. 2017;66(49):1341-1346. doi:10.15585/mmwr.mm6649a1PubMedGoogle ScholarCrossref
    34.
    Odani  S, Armour  BS, Graffunder  CM, Willis  G, Hartman  AM, Agaku  IT.  State-specific prevalence of tobacco product use among adults: United States, 2014-2015.  MMWR Morb Mortal Wkly Rep. 2018;67(3):97-102. doi:10.15585/mmwr.mm6703a3PubMedGoogle ScholarCrossref
    35.
    Hu  SS, Homa  DM, Wang  T,  et al.  State-specific patterns of cigarette smoking, smokeless tobacco use, and e-cigarette use among adults: United States, 2016.  Prev Chronic Dis. 2019;16:E17. doi:10.5888/pcd16.180362PubMedGoogle Scholar
    36.
    Centers for Disease Control and Prevention. Behavioral Risk Factor Surveillance System. https://www.cdc.gov/brfss/. Accessed February 1, 2019.
    37.
    von Elm  E, Altman  DG, Egger  M, Pocock  SJ, Gøtzsche  PC, Vandenbroucke  JP; STROBE Initiative.  The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies.  J Clin Epidemiol. 2008;61(4):344-349. doi:10.1016/j.jclinepi.2007.11.008PubMedGoogle ScholarCrossref
    38.
    Iachan  R, Pierannunzi  C, Healey  K, Greenlund  KJ, Town  M.  National weighting of data from the Behavioral Risk Factor Surveillance System (BRFSS).  BMC Med Res Methodol. 2016;16(1):155. doi:10.1186/s12874-016-0255-7PubMedGoogle ScholarCrossref
    39.
    Chaloupka  FJ, Straif  K, Leon  ME; Working Group, International Agency for Research on Cancer.  Effectiveness of tax and price policies in tobacco control.  Tob Control. 2011;20(3):235-238. doi:10.1136/tc.2010.039982PubMedGoogle ScholarCrossref
    40.
    Chaloupka  FJ, Yurekli  A, Fong  GT.  Tobacco taxes as a tobacco control strategy.  Tob Control. 2012;21(2):172-180. doi:10.1136/tobaccocontrol-2011-050417PubMedGoogle ScholarCrossref
    41.
    Hoffman  SJ, Tan  C.  Overview of systematic reviews on the health-related effects of government tobacco control policies.  BMC Public Health. 2015;15:744. doi:10.1186/s12889-015-2041-6PubMedGoogle ScholarCrossref
    42.
    Astor  RL, Urman  R, Barrington-Trimis  JL,  et al.  Tobacco retail licensing and youth product use.  Pediatrics. 2019;143(2):e20173536. doi:10.1542/peds.2017-3536PubMedGoogle Scholar
    43.
    Benmarhnia  T, Pierce  JP, Leas  E,  et al.  Can e-cigarettes and pharmaceutical aids increase smoking cessation and reduce cigarette consumption? findings from a nationally representative cohort of American smokers.  Am J Epidemiol. 2018;187(11):2397-2404. doi:10.1093/aje/kwy129PubMedGoogle ScholarCrossref
    44.
    Barrington-Trimis  JL, Urman  R, Berhane  K,  et al.  E-Cigarettes and future cigarette use.  Pediatrics. 2016;138(1):e20160379. doi:10.1542/peds.2016-0379PubMedGoogle Scholar
    45.
    Berry  KM, Fetterman  JL, Benjamin  EJ,  et al.  Association of electronic cigarette use with subsequent initiation of tobacco cigarettes in US youths.  JAMA Netw Open. 2019;2(2):e187794. doi:10.1001/jamanetworkopen.2018.7794PubMedGoogle Scholar
    46.
    Chapman  S, Bareham  D, Maziak  W.  The gateway effect of e-cigarettes: reflections on main criticisms.  Nicotine Tob Res. 2019;21(5):695-698. doi:10.1093/ntr/nty067PubMedGoogle ScholarCrossref
    47.
    Kandel  ER, Kandel  DB.  A molecular basis for nicotine as a gateway drug.  N Engl J Med. 2014;371(10):932-943. doi:10.1056/NEJMsa1405092PubMedGoogle ScholarCrossref
    48.
    Etter  JF.  Gateway effects and electronic cigarettes.  Addiction. 2018;113(10):1776-1783. doi:10.1111/add.13924PubMedGoogle ScholarCrossref
    49.
    Lee  PN, Coombs  KJ, Afolalu  EF.  Considerations related to vaping as a possible gateway into cigarette smoking: an analytical review.  F1000Res. 2018;7:1915. doi:10.12688/f1000research.16928.1PubMedGoogle ScholarCrossref
    50.
    Avino  P, Scungio  M, Stabile  L, Cortellessa  G, Buonanno  G, Manigrasso  M.  Second-hand aerosol from tobacco and electronic cigarettes: evaluation of the smoker emission rates and doses and lung cancer risk of passive smokers and vapers.  Sci Total Environ. 2018;642:137-147. doi:10.1016/j.scitotenv.2018.06.059PubMedGoogle ScholarCrossref
    51.
    Visser  WF, Klerx  WN, Cremers  HWJM, Ramlal  R, Schwillens  PL, Talhout  R.  The health risks of electronic cigarette use to bystanders.  Int J Environ Res Public Health. 2019;16(9):E1525. doi:10.3390/ijerph16091525PubMedGoogle Scholar
    52.
    Bals  R, Boyd  J, Esposito  S,  et al.  Electronic cigarettes: a task force report from the European Respiratory Society.  Eur Respir J. 2019;53(2):1801151. doi:10.1183/13993003.01151-2018PubMedGoogle Scholar
    53.
    Gentzke  AS, Creamer  M, Cullen  KA,  et al.  Vital signs: tobacco product use among middle and high school students—United States, 2011-2018.  MMWR Morb Mortal Wkly Rep. 2019;68(6):157-164. doi:10.15585/mmwr.mm6806e1PubMedGoogle ScholarCrossref
    54.
    US Department of Health and Human Services; Public Health Service; Office of the Surgeon General.  E-Cigarette Use Among Youth and Young Adults: A Report of the Surgeon General. Rockville, MD: US Department of Health and Human Services; 2016.
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