Key points are not available for this paper at this time.
This work was funded by a Chief Scientist Office Postdoctoral Training Fellowship in Health Services Research and Health of the Public Research (Ref PDF/12/06). The views expressed here are those of the authors and not necessarily those of the Chief Scientist Office. S.B. reports grants from Chief Scientist Office Scotland during the conduct of the study. His institution has received support from Pharmaceutical companies (for educational seminars), which is not related to the submitted work. D.J.M., A.M. and A.J.L. have no conflicts of interest to declare.
McLernon et al. (Mon,) studied this question.