Personalised medicine, new discoveries and studies on rare exposures or outcomes require large samples that are increasingly difficult for any single investigator to obtain. Collaborative work is limited by heterogeneities, both what is being collected and how it is defined. To develop a core set for data collection in rheumatoid arthritis (RA) research which (1) allows harmonisation of data collection in future observational studies, (2) acts as a common data model against which existing databases can be mapped and (3) serves as a template for standardised data collection in routine clinical practice to support generation of research-quality data. A multistep, international multistakeholder consensus process was carried out involving voting via online surveys and two face-to-face meetings. A core set of 21 items ('what to collect') and their instruments ('how to collect') was agreed: age, gender, disease duration, diagnosis of RA, body mass index, smoking, swollen/tender joints, patient/evaluator global, pain, quality of life, function, composite scores, acute phase reactants, serology, structural damage, treatment and comorbidities. The core set should facilitate collaborative research, allow for comparisons across studies and harmonise future data from clinical practice via electronic medical record systems.

Academic Rheumatology Department King's College London London UK

Arthritis Research UK Centre for Epidemiology Manchester Academic Health Sciences Centre The University of Manchester Manchester UK

Biomedical Research Centre NIHR Birmingham Birmingham UK

Center for Rheumatology and Spine Diseases Centre of Head and Orthopaedics Copenhagen Center for Arthritis Research Rigshospitalet Glostrup Denmark

Department of Biomedical Informatics Columbia University New York USA

Department of Biostatistics MRC North West Hub for Trials Methodology Research University of Liverpool Liverpool UK

Department of Clinical Medicine Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark

Department of Internal Medicine 3 Division of Rheumatology Medical University Vienna Vienna Austria

Department of Medicine Solna Karolinska Institutet Stockholm Sweden

Department of Patient and Care Maastricht University Medical Centre Maastricht The Netherlands

Department of Rheumatology 1st Faculty of Medicine Charles University Prague Czech Republic

Department of Rheumatology and Clinical Immunology Charité University Medicine Berlin Berlin Germany

Department of Rheumatology AP HP Hopital Pitie Salpetriere Paris France

Department of Rheumatology Bernhoven Uden The Netherlands

Department of Rheumatology Erasmus Medical Center Rotterdam The Netherlands

Department of Rheumatology Hospital Garcia de Orta and Instituto de Medicina Molecular da Faculdade de Medicina Universidade de Lisboa Lisboa Portugal

Department of Rheumatology Karolinska University Hospital Stockholm Sweden

Department of Rheumatology Leiden University Medical Center Leiden The Netherlands

Department of Rheumatology Martina Hansens Hospital Gjettum Norway

Department of Rheumatology North Devon UK

Division of Rheumatology Department of Internal Medicine Specialties University Hospitals of Geneva Geneva Switzerland

Institute of Inflammation and Ageing Institute of Inflammation and Ageing Arthritis Research UK Rheumatoid Arthritis Pathogenesis Centre of Excellence and MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research University of Birmingham Birmingham UK

Institute of Rheumatology Institute of Rheumatology Prague Czech Republic

Instituto de Salud Musculoesquelética Instituto de Salud Musculoesquelética Madrid Spain

Janssen Research and Development Janssen Titusville USA

Medicine Faculty APHP Rheumatology B Department Paris Descartes University Cochin Hospital Paris France

NIHR Manchester Musculoskeletal Biomedical Research Unit Central Manchester NHS Foundation Trust Manchester Academic Health Science Centre Manchester UK

Norwegian University of Science and Technology Trondheim Norway

Patient Partner of Romanian League Against Rheumatism Bucharest Romania

Patient Research Partner Paris France

Research Center of Rheumatic Diseases Research Center of Rheumatic Diseases 'Sf Maria' Hospital University of Medicine and Pharmacy 'Carol Davila' Bucharest Romania

Rheumatology Department Gartnavel General Hospital Glasgow UK

Rheumatology Department Sorbonne Universités UPMC University Paris Paris France

Sandwell and West Birmingham Hospitals NHS Trust Birmingham UK

References provided by Crossref.org

Considerations for improving quality of care of patients with rheumatoid arthritis and associated comorbidities