Table 4 Association between results of the tests and the drug regimen from univariable and multivariable analysis
CharacteristicUnivariableMultivariable
Odds ratio (95% CI)p ValueOdds ratio (95% CI)p Value
TST
Presence of risk factor2.77 (1.22 to 6.27)0.0155.21 (1.92 to 14.2)0.001
BCG vaccination2.44 (0.74 to 8.01)0.146.14 (1.51 to 24.9)0.011
Corticosteroids0.83 (0.38 to 1.80)0.640.74 (0.32 to 1.72)0.49
DMARDs0.94 (0.43 to 2.06)0.870.75 (0.32 to 1.77)0.51
Interferon γ assay
Presence of risk factor23.8 (5.14 to 111)<0.00130.5 (5.76 to 162)<0.001
BCG vaccination0.47 (0.15 to 1.47)0.202.46 (0.59 to 10.2)0.22
Corticosteroids1.94 (0.70 to 5.39)0.211.11 (0.30 to 4.14)0.87
DMARDs1.50 (0.46 to 4.92)0.502.34 (0.52 to 10.6)0.27
TNFα inhibitors0.21 (0.07 to 0.63)0.0060.19 (0.05 to 0.76)0.019
  • Association between the presence of any risk factor for latent tuberculosis, BCG vaccination status or drug regimen and test results in univariable analysis and multivariable analysis including all independent variables. Results are shown for the TST and for the IFNγ assay. Note that none of the subjects had received a TNFα inhibitor when the TST was performed; therefore, this variable was not included in the multivariable model for TST. An odds ratio above one indicates that a positive test is more likely in patients with the characteristic compared with patients without the characteristic, an odds ratio below one indicates the opposite. An odds ratio of 0.21 indicates, for example, that the odds for a positive IFNγ assay is five times lower in patients with TNFα inhibitors than in patients without TNFα inhibitors.

  • DMARDs, disease-modifying antirheumatic drugs; IFNγ, interferon γ; TNFα, tumour necrosis factor α; TST, tuberculin skin test.