Incentives for promoting smoking cessation: What we still do not know (Editorial)

First paragraph: In a newly updated Cochrane Review, Cahill and Perera summarise the effectiveness of incentives for smoking cessation. Their disappointing conclusion is that while there is some evidence that incentives work in the short term, the effects generally dissipate, and there is still insufficient evidence to recommend their adoption into routine practice. Much therefore remains to be discovered, but what are the particular questions that this review highlights?