title: Is a "false-positive" clinical diagnosis of knee osteoarthritis just the early diagnosis of pre-radiographic disease?
abstract: OBJECTIVE
  In routine practice, diagnosis of knee osteoarthritis (OA) currently relies on the combination of conventional risk factors and the presence of cardinal signs and symptoms. However, their role in early diagnosis has received little attention compared with biomarker research.
  
  
  METHODS
  Using data from 122 adults ages ≥50 years with knee pain but no definite radiographic OA, we tested whether the clinical diagnostic probability of OA, based on risk factors, signs, and symptoms, was associated with subsequent incidence of radiographic OA 3 years later.
  
  
  RESULTS
  Clinical diagnostic probability performed only modestly in discriminating incident radiographic knee OA (area under the receiver operating characteristic curve = 0.59, 95% confidence interval 0.49-0.70).
  
  
  CONCLUSIONS
  Improving the measurement of conventional markers and using study designs that test the ability of new biomarkers to add to or replace conventional markers are priorities for research in the early diagnosis of OA.
authors.affiliation: Keele University, Staffordshire, UK. g.m.peat@cphc.keele.ac.uk
authors.forename: George
authors.initials: G
authors.lastname: Peat
authors.forename: Elaine
authors.initials: E
authors.lastname: Thomas
authors.forename: Rachel
authors.initials: R
authors.lastname: Duncan
authors.forename: Laurence
authors.initials: L
authors.lastname: Wood
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D042241:Early Diagnosis; D005189:False Positive Reactions; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011859:Radiography