. Author manuscript; available in PMC: 2013 Jul 1.
Published in final edited form as: Ann Rheum Dis. 2012 Mar 22;71(7):1197–1202. doi: 10.1136/annrheumdis-2011-200901
Copyright Article author (or their employer) 2012. Produced by BMJ Publishing Group Ltd (& EULAR) under licence.