Lookup NU author(s): Professor Allyson Pollock,
This is the authors' accepted manuscript of an article that has been published in its final definitive form by BMJ Publishing Group, 2017.
For re-use rights please refer to the publisher's terms and conditions.
Author(s): Pollock AM, Kirkwood G
Publication type: Article
Publication status: Published
Online publication date: 25/09/2017
Acceptance date: 22/09/2017
Publisher: BMJ Publishing Group
Notes: Online from 26 Sep 17; to go in the print journal with full citation in due course