Medical University of Vienna - Section for Outcomes Research, Medical University of Vienna - Section for Outcomes Research, Medical University of Vienna - Section for Outcomes Research, Medical University of Vienna - Section for Outcomes Research, University of British Columbia - Department of Physical Therapy, University of British Columbia - Department of Physical Therapy, University of Magdalena - Faculty of Health Science, University of Sheffield - Unit of Oral Health, Griffith University - School of Applied Psychology, University of Social Welfare and Rehabilitation Sciences - Department of Nursing, University of Michigan at Ann Arbor - Department of Physical Medicine and Rehabilitation, Universidade de Coimbra - Centro Hospitalar, Dietology Austria, The Cyprus League Against Rheumatism and Platform Organization for People for Rheumatic Diseases in Southern Europe, Childrens Hospital Los Angeles, Diakonhjemmet Hospital - 3Department of Rheumatology, UCLA Health System - Department of Radiation Oncology, University of Michigan at Ann Arbor - Department of Physical Medicine and Rehabilitation, University of Johannesburg - Department of Podiatry, Medical University of Vienna - Section for Outcomes Research, University of North Carolina at Chapel Hill - Division of Pediatric and Public Health, Savvy Cooperative and Danube University Krems - Department for Evidencebased Medicine and Evaluation