title: Comparability of patients with ANCA-associated vasculitis enrolled in clinical trials or in observational cohorts.
abstract: OBJECTIVE
  To analyse the differences between patients with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) entered into randomised clinical trials (RCTs) and those followed in large observational cohorts.
  
  
  METHODS
  The main characteristics and outcomes of patients with generalised and/or severe GPA or MPA with a five-factor score ≥ 1 enrolled in the French Vasculitis Study Group (FVSG) or the US-Canadian-based Vasculitis Clinical Research Consortium cohorts were compared to those enrolled in one of 2 FVSG clinical RCTs (WEG91, WEGENT) or 3 European Vasculitis Society clinical trials (CYCLOPS, CYCAZAREM, IMPROVE).
  
  
  RESULTS
  657 patients (65.3% with GPA) in RCTs were compared to 437 in cohorts (90.6% with GPA). RCT patients were older at diagnosis than the cohort patients (56.6 ± 13.9 vs. 46.8 ± 17.3 years), had higher Birmingham vasculitis activity score (19.5 ± 9.1 vs. 16.9 ± 7.4), and more frequent kidney disease (84.0% vs. 54.9%) but fewer ear, nose, and throat symptoms (56.8% vs. 72.2%). At 56 months post-diagnosis, mortality and relapse rates, adjusted for age and renal function, were higher for patients with GPA in RCTs vs. cohorts (10.7% vs. 2.5% [p=0.001] and 22.5% vs. 15.6% [p=0.03], respectively) but similar for patients with MPA (6.2% vs. 6.6% [p=0.92] and 16.6% vs. 10.1% [p=0.39], respectively).
  
  
  CONCLUSIONS
  Patients with GPA or MPA in RCTs and those in observational cohorts show important differences that should be remembered when interpreting results based on these study populations.
authors.affiliation: Division of Rheumatology, University of Toronto, Canada, and Department of Internal Medicine, National Referral Center for Necrotising Vasculitides and Systemic Sclerosis, Department of Internal Medicine, Hôpital Cochin, University of Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Pagnoux
authors.affiliation: Division of Rheumatology, University of Toronto, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Carette
authors.affiliation: Division of Rheumatology, McMaster University, Hamilton, Canada.
authors.forename: N A
authors.initials: NA
authors.lastname: Khalidi
authors.affiliation: Division of Nephrology and Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Walsh
authors.affiliation: University of Cambridge and Lupus and Vasculitis Unit, Addenbrookes Hospital, Cambridge, UK.
authors.forename: T F
authors.initials: TF
authors.lastname: Hiemstra
authors.affiliation: Department of Biostatistics, University of South Florida, Tampa, USA.
authors.forename: D
authors.initials: D
authors.lastname: Cuthbertson
authors.affiliation: Center for Vasculitis Care and Research, Cleveland, USA.
authors.forename: C
authors.initials: C
authors.lastname: Langford
authors.affiliation: Center for Vasculitis Care and Research, Cleveland, USA.
authors.forename: G
authors.initials: G
authors.lastname: Hoffman
authors.affiliation: Division of Rheumatology, University of Utah, Salt Lake City, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Koening
authors.affiliation: Boston University Vasculitis Center, Boston, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Monach
authors.affiliation: Vasculitis Center, University of Pittsburgh Medical Center, Pittsburgh, USA.
authors.forename: L
authors.initials: L
authors.lastname: Moreland
authors.affiliation: Department of Internal Medicine, National Referral Center for Necrotising Vasculitides and Systemic Sclerosis, Department of Internal Medicine, Hôpital Cochin, University Paris-Descartes, Paris, France.
authors.forename: L
authors.initials: L
authors.lastname: Mouthon
authors.affiliation: Boston University Vasculitis Center, Boston, USA.
authors.forename: P
authors.initials: P
authors.lastname: Seo
authors.affiliation: Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, USA.
authors.forename: U
authors.initials: U
authors.lastname: Specks
authors.affiliation: Division of Rheumatology, Mayo Clinic, Rochester, USA.
authors.forename: S
authors.initials: S
authors.lastname: Ytterberg
authors.affiliation: Department of Nephrology and Transplantation, Lund University, Skane University Hospital Malmö, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Westman
authors.affiliation: Competence Centre for Clinical Research, Skane University, Lund, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Hoglund
authors.affiliation: School of Immunity and Infection, University of Birmingham, Birmingham, UK.
authors.forename: L
authors.initials: L
authors.lastname: Harper
authors.affiliation: Department of Nephrology, Royal Berkshire Hospital, Reading, Berkshire, UK.
authors.forename: O
authors.initials: O
authors.lastname: Flossman
authors.affiliation: Department of Nephrology, Nuffield Orthopaedic Centre, University of Oxford, Oxford, UK.
authors.forename: R
authors.initials: R
authors.lastname: Luqmani
authors.affiliation: School of Immunity and Infection, University of Birmingham, Birmingham, UK.
authors.forename: C O
authors.initials: CO
authors.lastname: Savage
authors.affiliation: Department of Ear, Nose and Throat, Rigshospitalet, Copenhagen, Denmark.
authors.forename: N
authors.initials: N
authors.lastname: Rasmussen
authors.affiliation: Klinikum Offenbach, Offenbach, Germany.
authors.forename: K
authors.initials: K
authors.lastname: de Groot
authors.affiliation: Department of Nephrology, Charles University and General University Hospital First Faculty of Medicine, Prague, Czech Republic.
authors.forename: V
authors.initials: V
authors.lastname: Tesar
authors.affiliation: University of Cambridge and Lupus and Vasculitis Unit, Addenbrookes Hospital, Cambridge, UK.
authors.forename: D
authors.initials: D
authors.lastname: Jayne
authors.affiliation: Vasculitis Center, Division of Rheumatology, University of Pennsylvania, Philadelphia, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Merkel
authors.affiliation: Department of Internal Medicine, National Referral Center for Necrotising Vasculitides and Systemic Sclerosis, Department of Internal Medicine, Hôpital Cochin, University Paris-Descartes, Paris, France.
authors.forename: L
authors.initials: L
authors.lastname: Guillevin
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000276:immunology; D015331:Cohort Studies; D005260:Female; D014890:Granulomatosis with Polyangiitis / Q000150:complications / Q000453:epidemiology* / Q000276:immunology; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology; D008297:Male; D055953:Microscopic Polyangiitis / Q000150:complications / Q000453:epidemiology* / Q000276:immunology; D008875:Middle Aged; D053146:Myeloblastin / Q000276:immunology; D064887:Observational Studies as Topic; D010038:Otorhinolaryngologic Diseases / Q000209:etiology; D018579:Patient Selection; D009195:Peroxidase / Q000276:immunology; D016032:Randomized Controlled Trials as Topic; D012720:Severity of Illness Index
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D009195:Peroxidase; D053146:Myeloblastin