Table 5

Multivariate linear regression models exploring the independent association between SF-36 MCS (dependent variable) and other clinical and demographic variables

SF-36 MCS (model 1)SF-36 MCS (model 2)SF-36 MCS (model 3)SF-36 MCS (model 4)
B (95% CI)βp ValueB (95% CI)βp ValueB (95% CI)βp ValueB (95% CI)βp Value
BASFI−1.181 (−2.042 to −0.319)−0.2080.007−0.844 (−1.707 to 0.020)−0.1490.056
ASDAS−0.736 (−2.574 to 1.101)−0.0580.430−1.817 (−3.501 to −0.132)−0.1430.035
BASDAI−1.275 (−2.311 to −0.239)−0.1800.016−1.736 (−2.664 to −0.809)−0.245<0.001
Disease duration0.497 (−1.097 to 2.091)0.0450.5400.336 (−1.230 to 1.902)0.0310.6730.873 (−0.721 to 2.467)0.0790.2810.492 (−1.076 to 2.060)0.0450.537
Age−0.043 (−0.209 to 0.124)−0.0400.612−0.055 (−0.219 to 0.108)−0.0510.505−0.093 (−0.258 to 0.072)−0.0860.267−0.087 (−0.248 to 0.074)−0.0810.286
BMI−0.373 (−0.746 to 0.000)−0.1400.050−0.376 (−0.743 to −0.009)−0.1410.045−0.491 (−0.860 to −0.123)−0.1840.009−0.451 (−0.813 to −0.090)−0.1690.015
Gender (male)0.178 (−3.282 to 3.638)0.0070.919−0.258 (−3.673 to 3.158)−0.0100.8820.590 (−2.909 to 4.088)0.0230.740−0.204 (−3.641 to 3.234)−0.0080.907
R2=0.10R2=0.12R2=0.07R2=0.10
adjR2=0.07adjR2=0.10adjR2=0.04adjR2=0.08
  • p Values <0.05 are highlighted in bold.

  • adjR2, adjusted R2, a better estimate of the population value of R2; ASDAS, Ankylosing Spondylitis Disease Activity Score; B, regression coefficient; β, standardised coefficient; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; BMI, Body Mass Index; R2, an estimate of the proportion of variance in the dependent variable accounted for by the regression; SF-36 PCS, SF-36 Physical Component Summary Score; SF-36 MCS, SF-36 Mental Component Summary Score.