Treat-to-target in axial spondyloarthritis: an observational study in daily practice

Objectives To evaluate the extent to which internationally agreed treat-to-target (T2T) recommendations were applied in clinical practice in patients with axial spondyloarthritis (axSpA). 
Methods Data were used from a web-based patient registry for monitoring SpA in daily practice in the Netherlands (SpA-Net). The extent to which T2T was applied was evaluated through four indicators: the proportion of patients 1) with ≥1 Ankylosing Spondylitis Disease Activity Score (ASDAS) assessed during a 1-year period, 2) having inactive disease/low disease activity (ID/LDA, i.e. ASDAS < 2.1), 3) in whom re-evaluation of ASDAS within recommended intervals occurred, and 4) with high disease activity (HDA, i.e. ASDAS ≥ 2.1) in whom treatment was adapted ≤6 weeks after obtaining ASDAS ≥ 2.1. Patients with HDA with treatment adaptations were compared with patients with HDA without treatment adaptations. 
Results In 185 out of 219 patients (84%), disease activity was monitored with ≥1 ASDAS during a 1-year period, of whom 71 (38%) patients had a score below the target (ASDAS < 2.1) at first measurement. Re-evaluation of ASDAS ≤3 months occurred in 11% and 23% of the patients with ID/LDA and HDA, respectively. Treatment adaptation occurred in 19 out of 114 patients (13%) with HDA. Patients in whom treatment was adapted, had significantly higher ASDAS (p< 0.01), C-reactive protein levels (p< 0.05), and physician global assessment (p< 0.05) compared with patients without treatment adaptations. 
Conclusions T2T was applied to a limited extent in clinical practice in patients with axSpA. Available disease activity scores seemed not to be used for determining the frequency of re-evaluation nor treatment adaptation.