Ellison, Gillian
Wallace, Andrew
Kohlmann, Alexander
Patton, Simon
Article History
Received: 10 January 2017
Revised: 24 May 2017
Accepted: 21 June 2017
First Online: 27 July 2017
Competing interests
: GE and AK are employees of AstraZeneca plc. The remaining authors declare no conflict of interest.