Table 4

Longitudinal relationship between ASDAS and radiographic damage in different strata

Stratification forStratum analysedMultivariable regression models (autoregressive and time-lagged)
ß (95%CI)*
GenderASDAS in males (n=129)0.98 (0.56 to 1.39)
ASDAS in females (n=54)†−0.06 (−0.40 to 0.27)
Symptom duration‡ASDAS in symptom duration <18 years (n=92)0.84 (0.42 to 1.26)
ASDAS in symptom duration ≥18 years (n=80)0.16 (−0.22 to 0.54)
Gender and symptom duration‡ASDAS in women, symptom duration <18 years (n=24)0.21 (0.03 to 0.38)
ASDAS in women, symptom duration ≥18 years (n=29)−0.06 (−0.63 to 0.51)
ASDAS in men, symptom duration <18 years (n=68)0.94 (0.43 to 1.45)
ASDAS in men, symptom duration ≥18 years (N=51)0.36 (−0.12 to 0.84)
  • *Results refer to different multivariable models. Stratifications were made due to significant interactions. The ß indicates the progression in mSASSS per unit increase in ASDAS per 2 years. In italic are the strata in which there is a significant effect of disease activity (as measured by the ASDAS) on radiographic damage (as measured by the mSASSS).

  • †One patient had a missing in one of the items of the ASDAS (BASDAI question 3) and therefore ASDAS could not be calculated.

  • ‡Symptom duration was not available for 12 patients who could therefore not be included in this stratified analysis.

  • ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath AS Disease Activity Index; mSASSS, modified Stoke Ankylosing Spondylitis Spine Score.