Holmes, R D
Tiwari, A K
Kennedy, J L
Article History
Received: 30 July 2014
Revised: 17 November 2015
Accepted: 20 January 2016
First Online: 22 March 2016
Competing interests
: R.D.H and A.K.T have no conflicts of interest to declare. J.L.K. has been a consultant to GSK, Sanofi-Aventis and Dainippon-Sumitomo and received honoraria from Eli Lilly.