1. Department of Epidemiology and Preventive Medicine, Monash University; Monash Department of Clinical Epidemiology at Cabrini Hospital; Suite 41, Cabrini Medical Centre 183 Wattletree Road Malvern Victoria Australia 3144
2. Concord Hospital; Department of Rheumatology; Concord New South Wales Australia
3. Leiden University Medical Center; Department of Public Health and Primary Care; PO Box 9600 Leiden Netherlands 2300 RC
4. Monash University; Department of Surgery, Monash Medical Centre; Postal address: Melbourne Shoulder and Elbow Centre 31 Normanby Street Brighton Victoria Australia 3186