1. Key findings from scoping review
Estimating the Public Health Impact of E-Cigarette Use in Canada: An Agent Base Modelling Approach
R. Edjoc PhD1,4, H. Orpana PhD1, 3 , R. Wall PhD1, N. Osgood PhD2, and K. Kreuger PhD (c)2
1Science Integration Division, Social Determinants and Science Integration Directorate, Public Health Agency of Canada, Ottawa, Canada
2Department of Computer Science, University of Saskatchewan, Saskatoon SK, 3 School of Psychology, University of Ottawa, 4 School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa
Introduction
The use of electronic cigarettes (e-cigarettes) has rapidly increased and almost doubled from 2008 to 2012 in several countries [1].
In Canada in 2013, 9% of those 15 years and older (approximately 2.5 million users) report ever having tried an e-cigarette while 2% had used an e-cigarette in the last 30 days based on data from the Canadian Tobacco, Alcohol and Drugs Survey (CTADS)[2].
19.8% and 201.1% of users are youth and young adults (15-24 years old respectively) [2].
With such a high penetration rate especially in youth and young adults [2], it is important to understand the potential public health impact of this phenomenon.
Our objectives are to use agent based modelling to determine: 1) The potential impact of e-cigarettes on smoking cessation rates; 2) the potential impact of e-cigarettes in the reduction of cigarette use in current smokers; and, 3) the potential role of e-cigarettes as a gateway mechanism for non-smokers to start smoking.
Key findings from scoping review
Adjusted logistic regression estimates for E-cigarette use, CTADS )
Socio-demographic parameters
Odds ratio
95% Lower CI
95% Upper CI
Sex
Male
0.8
0.6
1.1
Female
1.0 -
Age
15-19
34.1
23.2
50.1
20-24
14.3
10.1
20.3
25-34
4.7
3.0
7.5
35-44
2.7
1.9
3.9
45+
Smoking status
Current smoker
67.3
49.3
92.0
Former smoker
9.7
6.4
14.6
Experimental smoker
4.1
2.8
6.1
Life-time abstainer
Urban dwelling
Urban
0.9
1.5
Rural
Health status
Excellent/Very Good/Good
0.5
1.3
Fair/Poor
Smoking cessation
Meta analysis [10]of two clinical trials [11,12] suggested an increase likelihood of smoking cessation by using e-cigarettes (RR=2.3; 95% CI: ).
Smoking reduction
Among smokers, e-cigarette use was associated with a 50% reduction (3 reported studies) in cigarette consumption, a reduction in mean cigarette consumption (21.9 to 1.7) (1 study) was observed in cohort studies [5-8]
Smoking Initiation
Leventhal et al. [3] found that for e-cigarette users were 4 times as likely to use other tobacco products at the start of their study
Wills et al. [4] found at a year follow-up, never smokers who tried e-cigarettes were three times more likely to have smoked cigarettes (adjusted OR =2.9; 95% CI: )
Methods
We performed an initial scoping review from Jan 2008-Jan 2016 to map out potential connections between conventional smoking behaviours and e-cigarette use. We used key terms: e-cigarette, electronic nicotine delivery systems, cessation, initiation, reduction and smoking. We searched Scopus, Medline and the grey literature for relevant papers.
We analyzed the Canadian Tobacco and Alcohol Drugs Survey (CTADS) 2013 to obtain prevalence of e-cigarette use, current smoking, smoking cessation and the association of these behaviours with e-cigarette use. Bootstrap replicate weights were used for variance estimation using the BRR varmethod function and a FAY factor of CTADS 2013 is a national representative cross-sectional survey (n=14 565) with a response rate of 81.8%.
Based on updated data from our review and data analysis, an agent based model (ABM) will be developed. ABM allows you to simulate the net effect of actions and individual/environmental interactions of individual behaviours on population outcomes.
Impacts and next steps
The scoping review literature review is currently being updated.
An analysis of the CTADS 2015 and CCHS 2014 will be conducted to update prevalence and OR data. These updated analyses will include other factors such as self-reported mental health, smoking intensity, e-cigarette use in the last 30 days, education and income levels. We will conduct sex and gender based analysis (i.e. are there differences in e-cigarette use in male and female users).
We are currently working to develop an ABM of e-cigarette use using the conceptual model as a template and prevalence/ORs as baseline data.
This ABM model will model the potential effects of e-cigarette use on smoking behaviours (initiation and reduction) and smoking cessation.
Prevalence of E-cigarette use (ever use) in Canada, CTADS 2013
OUTPUTS/RESULTS
References
Out of 662 articles, 29 articles were kept for review. Our review found some evidence to support the use of e-cigarettes in smoking cessation and harm reduction though sample and effect sizes were an issue (in clinical studies).
Population based studies provided contrary results. Grana et al [1] found that e-cigarettes reduced the likelihood of quitting.
However, some evidence seems to suggest e-cigarettes may increase the risk of non-smokers to initiate cigarette smoking.
Our analyses of the CTADS 2013 found that year olds had the highest prevalence of e-cigarette use compared to other age groups and smokers are most likely to use e-cigarettes compared to former and non-smokers.
[1] Grana R, Benowitz N, Glantz SA. E-cigarettes: a scientific review. Circulation May 13;129(19):
[2] Czoli C, Reid J, Rynard V, Hammond D. E-cigarettes in Canada-Tobacco Use in Canada: Pattern and Trends, 2015 edition, special Supplement
[3] Leventhal AM, Strong DR, Kirkpatrick MG, Unger JB, Sussman S, Riggs NR, et al. Association of Electronic Cigarette Use With Initiation of Combustible Tobacco Product Smoking in Early Adolescence. JAMA Aug 18;314(7):700-7.
[4] Wills TA, Knight R, Sargent JD, Gibbons FX, Pagano I, Williams RJ. Longitudinal study of e-cigarette use and onset of cigarette smoking among high school students in Hawaii. Tob Control Jan 25.
[5] Caponnetto P, Campagna D, Cibella F, Morjaria JB, Caruso M, Russo C, et al. EffiCiency and Safety of an eLectronic cigAreTte (ECLAT) as tobacco cigarettes substitute: a prospective 12-month randomized control design study. PLoS One. 2013;8(6):e66317.
[6]Polosa R, Caponnetto P, Morjaria JB, Papale G, Campagna D, Russo C. Effect of an electronic nicotine delivery device (e-Cigarette) on smoking reduction and cessation: a prospective 6-month pilot study. BMC Public Health. 2011;11:786.
[7]Caponnetto P, Polosa R, Auditore R, Minutolo G, Signorelli M, Maglia M, et al. Smoking cessation and reduction in schizophrenia (SCARIS) with e-cigarette: study protocol for a randomized control trial. Trials. 2014;15:88.
[8]Ely J. Evaluation of the use of e-cigarettes in rural smoking cessation programme
[9] McRobbie H, Bullen C, Hartmann-Boyce J, Hajek P. Electronic cigarettes for smoking cessation and reduction. Cochrane Database Syst Rev. 2014;12:CD
[10] Bullen C, Howe C, Laugesen M, McRobbie H, Parag V, Williman J, et al. Electronic cigarettes for smoking cessation: a randomised controlled trial. Lancet Nov 16;382(9905):
[11] Caponnetto P, Campagna D, Cibella F, Morjaria JB, Caruso M, Russo C, et al. EffiCiency and Safety of an eLectronic cigAreTte (ECLAT) as tobacco cigarettes substitute: a prospective 12-month randomized control design study. PLoS One. 2013;8(6):e66317.
Acknowledgements: Graphics on this poster were obtained from pixabay.com