Table 3.

Variables associated with positive test results

VariableNo. of results (unless indicated otherwise)Univariate analysisbMultivariate analysisb
PositiveNegativeOdds ratioP valueOdds ratioP value
Variables associated with positive TSTn = 58n = 97
    Age (yr) (mean ± SD)52.9 ± 17.251.7 ± 15
        <50 yr2641
        >50 yr32560.90.761.180.67
    Diagnosis
        RA2252
        Non-RA36450.50.050.560.22
    DMARD use
        Yes2654
        No32430.650.190.870.75
    Steroid use
        Yes1947
        No39500.520.060.530.14
    TB exposure
        Yes1010
        No48871.810.221.730.3
    Chest X-ray suggestive of old TB
        Yes95
        No49923.380.043.50.05
    BCG vaccination
        Yes4162
        No17351.360.391.430.34
    Nationality
        Greek5293
        Non-Greek642.680.143.740.07
    Any risk factor for TB (≥1)a
        Yes4260
        No16371.60.12
Variables associated with positive T-SPOT.TB assayn = 39n = 116
    Age (yr) (mean ± SD)62.9 ± 1448.6 ± 14.8
        <50 yr760
        >50 yr32564.890.0019.990.0001
    Diagnosis
        RA2154
        Non-RA18621.330.431.450.53
    DMARD use
        Yes2357
        No16591.490.292.10.22
    Steroid use
        Yes1452
        No25640.690.330.330.07
    TB exposure
        Yes515
        No341010.990.990.890.86
    Chest X-ray suggestive of old TB
        Yes410
        No351062.210.760.480.31
    BCG vaccination
        Yes2479
        No15370.750.450.510.17
    Nationality
        Greek35110
        Non-Greek462.090.275.650.04
    TST-positive result
        No1384
        Yes26325.50.000028.060.00002
    Any risk factor for TB (≥1)a
        Yes3468
        No5484.80.002
Variables associated with positive QFT-GIT assayn = 32n = 123
    Age (yr) (mean ± SD)59.2 ± 14.650.4 ± 15.7
        <50 yr859
        >50 yr24642.770.024.510.005
    Diagnosis
        RA1659
        Non-RA16641.080.841.160.79
    DMARD use
        Yes1664
        No16590.920.840.730.56
    Steroid use
        Yes1056
        No22670.540.150.310.04
    TB exposure
        Yes317
        No291060.640.50.550.41
    Chest X-ray suggestive of old TB
        Yes1410
        No281131.610.441.290.72
    BCG vaccination
        Yes2281
        No10421.140.761.050.9
    Nationality
        Greek29116
        Non-Greek371.70.453.50.12
    TST-positive result
        No1582
        Yes17412.350.032.020.11
    Any risk factor for TB (≥1)a
        Yes2676
        No6472.680.04
  • 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 Statistically significant differences between groups (P < 0.05) are shown in bold.