eTable 2. Addressing the issues of e-cigarettes in public health.

Controversial issues	Germany	United Kingdom
Recommendation of use	Use is discouraged (21)	Under consideration recommending smokers who are unable or unwilling to stop smoking to switch (24)
Health risks	Aerosol contains fewer pollutants than tobacco smoke (2)	E-cigarettes are about 95% less harmful than cigarettes (24, 25)
	Harmlessness to health not proven (21)	Likely to improve public health (26)
	Vapor not toxin-free (2)	Carcinogenic chemicals are largely absent (24)
Aid for tobacco or nicotine cessation	No evidence for suitability as smoking cessation aid (22)	Emerging evidence for effectiveness as smoking cessation aid (24)
	May reduce the motivation to quit smoking (22)	Reduces craving for smoking and can therefore help to quit smoking (25)
Gateway to tobacco consumption	Could serve as gateway by imitating smoking (23)	No indications that use leads to increased smoking uptake (27)
Dual use	Risk of maintenance/increase of dependency (2)	No evidence for an increase in dependency (27)
Risk of passive exposure	Health can be impaired (2)	No identifiable risks for passive exposure (27)
Influence on public opinion	“Be aware of the dangers of e-cigarettes and e-shishas” (22)	“…growing misconception that e-cigarettes and tobacco cigarettes are similarly harmful.” (26)

Germany and the UK have developed divergent positions in their assessment of e-cigarettes. Examples for this are given in statements intended for the general public in Germany published by the Division of Cancer Prevention of the Deutsches Krebsforschungszentrum (2), the German Federal Center for Health Education (21), and the Aktionsbündnis Nichtrauchen (Alliance for Non-Smoking) (22, 23), which can be compared to those from the UK issued by the equivalent parties (The National Centre for Smoking Cessation and Training [25], Royal College of Physicians [26], and Action on Smoking and Health [27]