Table 2

Correlation analyses for related PRO endpoints of interest at week 16

Endpoint 1Endpoint 2N1Correlation coefficient value*
Tofacitinib 5 mg twice daily (N=133)Total back painSF-36v2, bodily pain129–0.76
Nocturnal spinal painSF-36v2, bodily pain129–0.69
FACIT-F total scoreBASDAI fatigue128–0.66
SF-36v2, physical functioningBASFI129–0.76
SF-36v2, mental healthEQ-5D-3L anxiety/depression129–0.69
Placebo (N=136)Total back painSF-36v2, bodily pain131–0.66
Nocturnal spinal painSF-36v2, bodily pain131–0.65
FACIT-F total scoreBASDAI fatigue130–0.60
SF-36v2, physical functioningBASFI131−0.71
SF-36v2, mental healthEQ-5D-3L anxiety/depression131−0.64
  • Data are from the week 16 analysis: data cut-off 19 December 2019; data snapshot 29 January 2020.

  • For SF-36v2 domains, norm-based scores were used.

  • *All correlations were ***p<0.001, based on Student’s t distribution (N1–2 degree of freedom) to test the null hypothesis of no correlation. Correlation coefficient values of ≤0.3, >0.30–≤0.60 and >0.60 were regarded as weakly, moderately and highly correlated, respectively.

  • BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; EQ-5D-3L, EuroQol-Five Dimension-Three Level Health Questionnaire; FACIT-F, Functional Assessment of Chronic Illness Therapy-Fatigue; N, number of patients in full analysis set; N1, number of patients with observation in both PRO endpoints for calculating the correlation; PRO, patient-reported outcome; SF-36v2, Short Form-36 Health Survey Version 2.