title: Performance of QuantiFERON-TB Gold and tuberculin skin test relative to subjects' risk of exposure to tuberculosis.
abstract: BACKGROUND
  Performance of QuantiFERON-TB Gold In-Tube (QFT-GIT) and tuberculin skin test (TST) has not been compared in a US college population with varying risk of tuberculosis exposure.
  
  
  METHODS
  We performed a retrospective chart review of students tested for tuberculosis at the University of Pennsylvania Student Health Service between 2009 and 2011. We stratified students into high-, low-, and no-risk categories for exposure to tuberculosis and compared QFT-GIT and TST performance in risk groups adjusting demographic characteristics.
  
  
  RESULTS
  During the study period, 15 936 tuberculosis tests were performed in 9483 college students. Coming from a tuberculosis-endemic country was the only risk factor significantly associated with having a positive result (odds ratio [OR] 12.9; 95% confidence interval [CI], 10.2-16.5). Test specificity was higher for TST than QFT-GIT (99.7% vs 91.4%; P < .0001). Application of a higher threshold for positivity improved comparability of QFT-GIT with TST in the low-risk group (adjusted OR [AOR] 1.2; 95% CI, .4-3.3) but not in the high-risk group (AOR .4; 95% CI, .3-.5).
  
  
  CONCLUSIONS
  QFT-GIT was less specific than TST. Our findings support the use of TST for US college students who need tuberculosis testing and the use of risk-stratified interpretation for students who are tested with QFT-GIT.
authors.affiliation: Student Health Service, University of Pennsylvania, Philadelphia.
authors.forename: Sharon E
authors.initials: SE
authors.lastname: McMullen
authors.forename: David A
authors.initials: DA
authors.lastname: Pegues
authors.forename: Frances S
authors.initials: FS
authors.lastname: Shofer
authors.forename: Alexandra C
authors.initials: AC
authors.lastname: Sheller
authors.forename: Evelyn B
authors.initials: EB
authors.lastname: Wiener
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D016017:Odds Ratio; D010414:Pennsylvania; D011237:Predictive Value of Tests; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013334:Students; D014374:Tuberculin Test; D014376:Tuberculosis / Q000175:diagnosis* / Q000276:immunology; D014481:United States
keywords: diagnostic techniques and procedures; interferon-gamma release tests; latent tuberculosis; sensitivity and specificity