Electronic cigarettes in physician practice: a complex debate.

E-cigarettes, or electronic nicotine delivery systems (ENDS), have been suggested as a potential aid for smoking cessation, but many questions about their efficacy and safety remain unanswered. Until very recently, the evidence for ENDS in smoking cessation was largely based on observational studies or randomised controlled trials with methodological flaws and did not provide adequate evidence to support strongly ENDS for smoking cessation. Concerns about the uptake of ENDS by nonsmoking populations (such as adolescents) remain. More recent evidence may indicate the effect of ENDS in smoking cessation, but many questions remain unanswered. In this article, we address recent claims that failure to recommend ENDS for smoking cessation represents unethical practice. We strongly dispute this claim, analysing the many complex issues that clinicians working in smoking cessation should consider.