Funding for this research was provided by:
Medical Research Council (G1000417/94909)
Arthritis Research UK (20380, 20385)
Received: 20 April 2017
Accepted: 18 February 2018
First Online: 20 March 2018
Ethics approval and consent to participate
: All participants provided informed consent and the study was approved by the East of England - Cambridgeshire and Hertfordshire Research Ethics Committee (REC:15/EE/0076).
: Not applicable.
: The authors declare that they have no competing interests.
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