title: Clinical predictors of positive temporal artery biopsy.
abstract: OBJECTIVE
  We investigated the ability of known clinical signs and symptoms, as well as common laboratory tests, to correctly predict a positive temporal artery biopsy.
  
  
  METHODS
  A prospective cohort study.
  
  
  METHODS
  Consecutive patients in a tertiary referral centre undergoing temporal artery biopsy.
  
  
  METHODS
  Clinical information was collected using a predesigned questionnaire. Pathology results and laboratory information were collected from digital patient records.
  
  
  METHODS
  The predictive value of clinical signs, symptoms, and laboratory values of a positive temporal artery biopsy.
  
  
  RESULTS
  Over a 3-year period, 259 patients were enrolled and 251 patients were analyzed. Sixty-one patients had a positive biopsy. Clinical features most predictive of a positive biopsy were jaw claudication (positive likelihood ratio [LR+] 2.31) and abnormal temporal artery pulse (LR+ 2.62). Receiver operating characteristic curves generated for erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and platelets values showed an area under curve (AUC) value of 0.71, 0.75, and 0.76, respectively. The initiation of steroids decreased the diagnostic utility of the ESR, CRP, and platelets values (AUC = 0.58, 0.61, and 0.63, respectively).
  
  
  CONCLUSIONS
  A variety of clinical signs and symptoms were observed in patients referred for a temporal artery biopsy. Clinical signs and symptoms were less accurate in predicting a positive biopsy than laboratory tests. No combination of clinical signs and symptoms tested was able to predict giant cell arteritis with the certainty necessary to justify or withhold long-term steroid therapy.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, University of Laval, Quebec, Que.
authors.forename: Andrew
authors.initials: A
authors.lastname: Toren
authors.affiliation: Department of Ophthalmology, University of Alberta, Edmonton, Alta.
authors.forename: Ezekiel
authors.initials: E
authors.lastname: Weis
authors.affiliation: USC Eye Institute, Keck School of Medicine, University Southern California, Los Angeles, Calif.
authors.forename: Vivek
authors.initials: V
authors.lastname: Patel
authors.affiliation: Department of General Internal Medicine, Faculty of Medicine, Queen's University, Kingston, Ont.
authors.forename: Bethany
authors.initials: B
authors.lastname: Monteith
authors.affiliation: Department of Ophthalmology, University of Ottawa Eye Institute, Ottawa, Ont.
authors.forename: Steven
authors.initials: S
authors.lastname: Gilberg
authors.affiliation: Department of Ophthalmology, University of Ottawa Eye Institute, Ottawa, Ont. Electronic address: jordan1897@rogers.com.
authors.forename: David
authors.initials: D
authors.lastname: Jordan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000378:metabolism; D015331:Cohort Studies; D005189:False Positive Reactions; D005260:Female; D013700:Giant Cell Arteritis / Q000175:diagnosis* / Q000188:drug therapy; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007383:Intermittent Claudication / Q000175:diagnosis; D007571:Jaw Diseases / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013699:Temporal Arteries / Q000473:pathology*
chemical_list: D005938:Glucocorticoids; D002097:C-Reactive Protein