Received: 7 August 2019
Accepted: 14 November 2019
First Online: 4 January 2020
Ethics approval and consent to participate
: Not applicable. Not required as no patients or animals involved in this study.
: Not applicable, as no patients involved in this study.
: SD Smith is a member of the advisory board at ABBVIE and Janssen Cilag and an investigator at ABBVIE and Novartis. The other authors declare that they have no conflict interests.