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Table 4 Predictors of persistent QFT-GIT positivity

From: Predictors of persistently positive Mycobacterium-tuberculosis-specific interferon-gamma responses in the serial testing of health care workers

  Positive Baseline and follow-up QFT-GIT  
Variables Adjusted OR* (95% CI) p-value
Age categorized# 5.0 (3.9-13.5) 0.001
Sex   
   Female 1 -
   Male 1.2 (0.2-6.3) 0.80
Birth in high-burden country   
   No 1 -
   Yes 0.2 (0.0-3.6) 0.29
BCG status 1 -
   Vaccinated 0.3 (0.1-1.5) 0.15
   Unknown 0.6 (0.0-9.8) 0.70
Profession   
   Other 1 -
   Nursing 0.6 (0.1-3.4) 0.57
   Physician 3.2 (0.5-22.7) 0.24
Affiliation with ID/TB Care   
   No 1 -
   Yes 0.8 (0.1-7.8) 0.85
Family history of TB   
   No 1 -
   Yes 1.1 (0.1-8.7) 0.96
QFT-GIT test interval per day 1.0 (0.99-1.01) 0.49
Exposure per hour§ 0.7 (0.45-1.13) 0.15
Prior TST   
   Negative 1 -
   Positive 14.2 (1.4-143.2) 0.024
Recent TST   
   Negative 1 -
   > 5 mm induration 12.1 (2.4-59.8) 0.002
   ≥ 10 mm induration 15.5 (3.1-81.3) 0.001
Baseline IFN-γ increase per 0.1 IU/ml 1.03 (1.01-1.04) 0.0006
  1. *Variables included in final model building were age, birth in high-burden country, BCG status, recent TST result > 5 mm or ≥ 10 mm induration, and baseline IFN-γ increase per 0.1 IU/ml. #Compare Table 1. §Exposure per hour in those 134 study subjects that were recruited from contact investigations. BCG = Bacillus Calmette-Guérin; CI = confidence interval; ID = Infectious Diseases; IFN = interferon; OR = odds ratio; QFT-GIT = QuantiFERON®-TB Gold In-Tube; TB = tuberculosis; TST = tuberculin skin test.