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Table 3 Baseline predictors of ASAS20 response at three months of anti-TNF-α treatment

From: Baseline predictors of response and discontinuation of tumor necrosis factor-alpha blocking therapy in ankylosing spondylitis: a prospective longitudinal observational cohort study

   Univariate analysis Multivariate analysis
   OR (95% CI) P-value OR (95% CI) P-value
Age (yr)†a   0.982 (0.959 to 1.006) 0.150 0.972 (0.947 to 0.998) 0.035
Gender Female 1 -   -
  Male 2.166 (1.185 to 3.958) 0.012 3.151 (1.580 to 6.285) 0.001
Duration of symptoms (yr)†   1.001 (0.976 to 1.028) 0.914   ***
HLA-B27 Negative 1 -   -
  Positive 0.779 (0.363 to 1.675) 0.523   ***
Peripheral arthritis Absent 1 -   -
  Present 2.120 (0.876 to 5.129) 0.096   **
BASDAI (range 0 to 10)‡   0.946 (0.793 to 1.129) 0.538   ***
ASDAS‡   1.458 (0.992 to 2.144) 0.055   *
Physician's GDA (range 0 to 10)‡   1.122 (0.983 to 1.282) 0.089   **
Patient's GDA (range 0 to 10)‡a   1.029 (0.882 to 1.201) 0.714   **
ESR (mm/h)‡a   1.016 (1.000 to 1.032) 0.049 1.023 (1.005 to 1.041) 0.014
CRP (mg/l)‡   1.021 (1.003 to 1.040) 0.025   *
BASFI (range 0 to 10)‡   0.939 (0.816 to 1.081) 0.382   ***
Chest expansion (cm)‡a   1.081 (0.948 to 1.233) 0.243   **
Modified Schober test (cm)‡   1.026 (0.861 to 1.224) 0.773   ***
Occiput to wall distance (cm)‡a   0.981 (0.942 to 1.022) 0.364   **
Lateral lumbar flexion L (cm)‡   1.027 (0.965 to 1.092) 0.402   ***
Lateral lumbar flexion R (cm)‡   1.029 (0.968 to 1.094) 0.352   ***
TNF-α blocking agent ETA 1 -   -
  IFX 2.045 (0.780 to 5.364) 0.146   **
  ADA 0.938 (0.476 to 1.846) 0.852   **
  1. See Table 1 for definitions.
  2. OR refers to the risk of achieving ASAS20 response: † per year; ‡ per 1 grade or 1 point.
  3. a Significant difference (P < 0.05) between men and women at baseline.
  4. * CRP and ASDAS were not selected during forward conditional logistic regression due to the strong correlation with ESR (ESR and CRP: ρ = 0.669, P = 0.000; ESR and ASDAS: ρ = 0.412, P = 0.000). Although, higher CRP level (OR: 1.024, 95% CI: 1.004 to 1.044) and higher ASDAS level (OR: 1.728, 95% CI: 1.126 to 2.652) were also significant predictors of ASAS20 response at three months in the presence of age and gender.
  5. ** The variable was not selected during multivariate regression analysis (P ≥0.05).
  6. *** The variable was not tested in multivariate regression analysis because of a P-value > 0.3 in univariate regression analysis and no significant difference between men and women at baseline.