1. Association of Youth electronic cigarette USE with subsequent cigarette smoking
Presented by
Cathy L. Backinger, PhD, MPH
Deputy Director for Research
Office of Science

2. overview Youth Studies Young Adults Meta-Analysis and Recent Reports
Summary
No financial disclosures

3. Youth Studies

4. Study characteristics - Youth
Authors
Year of Study Start
Place
Age or Grade
Study Length
Leventhal, et al. (2015)
2013
10 Los Angeles
public schools
9th graders (avg. 14.1)
12 months
Wills, et al. (2016)
Schools in Oahu, Hawaii
14-16 years
Barrington-Trimis, et al. (2016)
2014
Southern California
11th &12th graders (avg. 17.4)
16 months
Meich, et al. (2017)
U.S. National
12th graders
Connor et al. (2017)
20 U.K schools
13-14 years

5. Study characteristics - Youth
Authors
Year of Study Start
Place
Age or Grade
Study Length
Best et al. (2017)
2015
4 high schools Scotland
11-18 years
12 months
Bold et al. (2017)
2013
3 public school in CT
13-17 years
24 months
Treur et al. (2017)
19 secondary schools in Netherlands
11-17 years
6 months
Hammond et al. (2017)
89 secondary schools in Ontario and Alberta, Canada
Grades 9-12
Watkins et al.
(2018)
U.S. National
12-17 years

6. Measures - Youth Authors Sample of nonsmoking e-cig users
Covariates in addition to age or grade, sex, race/ethnicity, tobacco use
Leventhal, et al (2015)
222 - ever
Family and peer smoking, depression, substance use, impulsivity, delinquent behavior, susceptibility
Wills, et al (2016)
215 - ever
Parent support, sensation seeking, rebellion, parental monitoring
Barrington-Trimis, et al (2016)
146 – ever
94 - non-susceptible to smoking
Friend smoking, friend influences, smoking susceptibility
Meich, et al (2017)
54 - ever
Binge drinking, marijuana use, risk for smoking, risk perceptions
Connor et al. (2017)
343 - ever
SES, school, smoking susceptibility, peer and family smoking status

7. Measures - Youth Authors Sample of nonsmoking e-cig users
Covariates in addition to age or grade, sex, race/ethnicity
Best et al. (2017)
183 – ever
SES, smoking susceptibility, friends and family smoking,
Bold et al. (2017)
72 - current
SES, ever use of other tobacco products
Treur et al. (2017)
61 – ever with nicotine
279 – ever without nicotine
Education level, personality (anxiety, sensitivity, hopelessness, sensation seeking, impulsivity), susceptibility to peer pressure, smoking intention)
Hammond, et al. (2017)
343 – current, not susceptible to smoking
412 – current, susceptible to smoking
Smoking susceptibility, spending money
Watkins et al.
(2018)
425 – ever
87 - current
Parental education level, urban residence, sensation seeking, alcohol use, live with a tobacco user, notice of warning labels, receptivity to tobacco advertising

8. Percent of current E-cigarette Use among 13-15 Year olds, GYTS
Cigarette Smoking Among Youth E-Cigarette Users – longitudinal Studies
Percent of current E-cigarette Use among Year olds, GYTS OR 20 35 50
Odds Ratio of Ever E-Cigarette Use to
Ever Cigarette Smoking at Follow-up
Leventhal AM, et al. JAMA 2015
Wills TA, et al. Tob Control 2017
Barrington-Trimis JL, et al. Pediatrics 2016
Meich R et al. Tob Control 2017
Best C, et al. Tob Control 2017
Connor M, et al. Tob Control 2017
Treur JL, et al. European J Epi 2017
Watkins SL, et al. JAMA Ped 2018
* Among e-cig users not susceptible to cigarette smoking
** Relative risk

9. Percent of current E-cigarette Use among 13-15 Year olds, GYTS
Cigarette Smoking Among Youth E-Cigarette Users – longitudinal Studies
Percent of current E-cigarette Use among Year olds, GYTS OR 20 22
Bold KW, et al. Pediatrics 2017
Hammond D, et al. CMAJ 2017
Watkins SL, et al. JAMA Ped 2018

10. Young Adults 6 studies (7 analyses) conducted since 2012
4 analyzed ever e-cigarette use to ever smoking
3 analyzed current e-cigarette use to current smoking
6-18 months follow-up
Adjusted OR
Ever to ever:
Current to current: one study: not significant, other two studies: – 5.43

11. Meta-analysis and RECENT reports

12. Meta-analysis – youth and young adults
Soneji S et al., JAMA Pediatrics, 2017
Pooled data from 7 longitudinal studies of youth and youth adults users that examined ever e-cigarette users compared with never e- cigarette users at baseline and ever cigarette smoking
Adjusted for demographics, psychosocial and behavioral risk factors
Pooled odds ratio: 3.62 (95% CI, )
Data from 2 longitudinal studies of current (past 30-day use) cigarette smoking at follow-up among current e-cigarette user non- current cigarette smokers at baseline
Pooled odds ratio: 4.28 (95% CI, )

13. Public Health Consequences of E-Cigarettes
Report released January 23, 2018
Reviewed 10 studies of ever e- cigarette use to ever smoking: 6 youth, 4 young adults
Reviewed 8 studies of e-cigarette use and subsequent risk of recent smoking/heavier smoking of cigarettes: 3 youth, 5 young adults *

14. Public Health Consequences of E-Cigarettes
Conclusion 16-1:
“There is substantial evidence that e-cigarette use increases risk of ever using combustible tobacco cigarettes among youth and young adults.”
Substantial evidence: There are several supportive findings from good quality observational or controlled studies with very few or no credible opposing findings. A firm conclusion can be made, but minor limitations, including chance, bias, and confounding factors, cannot be ruled out with reasonable confidence.
“Results were consistent across a number of methodologies, age ranges, research groups, and locations, and the associations were of considerable strength.”

15. Evidence review of e-cigarettes and heated tobacco products 2018
Use of e-cigarettes among young people; key findings:
Despite some experimentation with these devices among never smokers, e-cigarettes are attracting very few young people who have never smoked into regular use
Never smokers in the UK who try e- cigarettes are more likely to have tried smoking subsequently than those who have not tried e-cigarettes. A causal link has not been established and neither has progression to regular smoking.

16. Summary

17. summary
Association of youth ever e-cigarette use with ever cigarette smoking
8 studies (10 analyses) conducted since 2013 with positive associations
6 -24 months
Adjusted OR ranged from 1.75 to 11.9
Other youth associations
1 study (2 analyses) of current e-cig use to current cigarette smoking: adjusted OR: 3.87 to 7.08
2 studies (3 analyses) of ever e-cig use to current smoking, current e-cig use to ever smoking, and current e-cig use to past 7 days daily smoking: adjusted OR: 1.79 to 2.12
Young adult studies
6 studies (7 analyses) since with positive associations, one not significant

18. summary Meta-analysis and recent reports All studies
Positive association for both youth and young adults ever e-cigarettes use to ever cigarette smoking
All studies
Variation in make-up of populations (age, race/ethnicity), geographic locations, tobacco use measures, covariates, and confidence intervals
No studies have shown a protective effect of e-cigarette use preventing ever cigarette smoking among youth and young adults
Does ever or current e-cigarette use lead to established smoking?
Research will inform this question and to help understand mechanisms

19. Thank you

20. Factors to consider when assessing Youth E-cigarette use*
Smoking and other tobacco use
Peer use/influences
Parent and family use/influences
Intrapersonal, e.g., depression, anxiety, sensation-seeking
Advertising
Appeal, e.g., flavors, ease of use, cloud tricks
Perceptions of health risks/effects
Alcohol, marijuana, and other substance use
Nicotine concentration
* Not an exhaustive list