title: Developing a provisional definition of flare in patients with established gout.
abstract: OBJECTIVE
  Various nonvalidated criteria for disease flare have been used in studies of gout. Our objective was to develop empirical definitions for a gout flare from patient-reported features.
  
  
  METHODS
  Possible elements for flare criteria were previously reported. Data were collected from 210 gout patients at 8 international sites to evaluate potential gout flare criteria against the gold standard of an expert rheumatologist definition. Flare definitions based on the presence of the number of criteria independently associated with the flare and classification and regression tree approaches were developed.
  
  
  RESULTS
  The mean ± SD age of the study participants was 56.2 ± 15 years, 207 of them (98%) were men, and 54 of them (26%) had flares of gout. The presence of any patient-reported warm joint, any patient-reported swollen joint, patient-reported pain at rest score of >3 (0-10 scale), and patient-reported flare were independently associated with the study gold standard. The greatest discriminating power was noted for the presence of 3 or more of the above 4 criteria (sensitivity 91% and specificity 82%). Requiring all 4 criteria provided the highest specificity (96%) and positive predictive value (85%). A classification tree identified pain at rest with a score of >3, followed by patient self-reported flare, as the rule associated with the gold standard (sensitivity 83% and specificity 90%).
  
  
  CONCLUSIONS
  We propose definitions for a disease flare based on self-reported items in patients previously diagnosed as having gout. Patient-reported flare, joint pain at rest, warm joints, and swollen joints were most strongly associated with presence of a gout flare. These provisional definitions will next be validated in clinical trials.
authors.affiliation: Birmingham VA Medical Center and University of Alabama at Birmingham, AL, USA.
authors.forename: Angelo L
authors.initials: AL
authors.lastname: Gaffo
authors.forename: H Ralph
authors.initials: HR
authors.lastname: Schumacher
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Saag
authors.forename: William J
authors.initials: WJ
authors.lastname: Taylor
authors.forename: Janet
authors.initials: J
authors.lastname: Dinnella
authors.forename: Ryan
authors.initials: R
authors.lastname: Outman
authors.forename: Lang
authors.initials: L
authors.lastname: Chen
authors.forename: Nicola
authors.initials: N
authors.lastname: Dalbeth
authors.forename: Francisca
authors.initials: F
authors.lastname: Sivera
authors.forename: Janitzia
authors.initials: J
authors.lastname: Vázquez-Mellado
authors.forename: Chung-Tei
authors.initials: CT
authors.lastname: Chou
authors.forename: Xuejun
authors.initials: X
authors.lastname: Zeng
authors.forename: Fernando
authors.initials: F
authors.lastname: Perez-Ruiz
authors.forename: Sergio C
authors.initials: SC
authors.lastname: Kowalski
authors.forename: Claudia
authors.initials: C
authors.lastname: Goldenstein-Schainberg
authors.forename: Lan
authors.initials: L
authors.lastname: Chen
authors.forename: Thomas
authors.initials: T
authors.lastname: Bardin
authors.forename: Jasvinder A
authors.initials: JA
authors.lastname: Singh
mesh_terms: D019937:Diagnostic Techniques and Procedures; D005260:Female; D006073:Gout / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D006074:Gout Suppressants / Q000627:therapeutic use; D006801:Humans; D007249:Inflammation / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology / Q000473:pathology; D012008:Recurrence; D012680:Sensitivity and Specificity; D009626:Terminology as Topic
chemical_list: D006074:Gout Suppressants