Fig. 3.

Effects of tofacitinib treatment on fatigue in initial mediation model B (BASDAI Q1-based). Estimated: a direct effect and overall indirect effect,^a b indirect effect via morning stiffness and pain or morning stiffness alone, c indirect effect via pain alone, and d indirect effect via C-reactive protein and pain or C-reactive protein alone. Results based on pooled data from phase 2 (NCT01786668) and phase 3 (NCT03502616) studies. Treatment was the independent binary variable (tofacitinib 5 mg BID versus placebo). Fatigue was based on BASDAI Q1 (observed variable). Pain was represented by BASDAI Q2 and Q3. Morning stiffness was considered an observed variable and was represented by the mean of BASDAI Q5 and Q6. CRP was considered an observed variable. BASDAI Bath Ankylosing Spondylitis Disease Activity Index, BID twice daily, CRP C-reactive protein, Q question