Evidence use in E-cigarettes debates: scientific showdowns in a 'wild west' of research.

E-cigarette debates are likely to reconcile only if a clear majority of participants in the uncertain 'middle ground' settle on a more fixed position. Our results suggest that many participants in Scottish e-cigarette debates occupy this 'middle ground' and express concerns that can be empirically assessed, implying evidence has the potential to play a more important role in settling e-cigarette debates than previous research suggests.