Table 2.

Risk factors for tuberculosis associated with a positive screening assay

Screening assay and risk factorOR95% CIP value
TST
    Chest X-ray suggestive of old TB3.51–12.20.05
T-SPOT.TB assay
    Age of >50 yr9.993.1–32.30.0001
    TST-positive result8.063.08–21.10.00002
    Non-Greek nationality5.651.08–29.50.04
    Any risk factor for TB (≥1)a4.8b1.75–13.20.002
QFT-GIT assay
    Age of >50 yr4.511.58–12.10.005
    Steroid use0.310.1–0.960.04
    Any risk factor for TB (≥1)a2.68b1.02–6.990.04
  • a Risk factors for TB included age of >50 years, chest X-ray suggestive of old/healed TB, contact with a person with TB, and birth or residence in a country with a high TB prevalence (non-Greek nationality).

  • b By univariate analysis (see details in Table 3). All other results were from multivariate analysis (as described in Materials and Methods).