Determinants of Tumor Necrosis Factor Inhibitor Use in Juvenile Spondyloarthropathy and Impact on Clinical Disease Outcomes

OBJECTIVE: The objectives of this study were to characterize the reasons for tumor necrosis factor inhibitor (TNFi) initiation in patients with juvenile spondyloarthropathy (JSpA) and identify clinical correlates and to assess the effect of TNFi therapy on JSpA disease activity. METHODS: We conducted a retrospective cohort study of 86 patients with JSpA with first‐time use of a TNFi over a 7‐year period at Stanford Children's Health. We assessed the physician's reason for TNFi initiation, disease activity at 6 months, and clinical disease status at 12 months following TNFi start. Changes in active joint count, enthesitis count, and pain were measured. Demographics, physician reasons for TNFi initiation, and clinical characteristics were summarized. RESULTS: The mean age at JSpA diagnosis was 12.4 years (SD 4.0 years), and the mean time from diagnosis to TNFi initiation was 1.6 years (SD 2.3 years). The most common reason for initiating a TNFi was active disease on physical examination (61%). At 6 months post TNFi initiation, patients on average had three fewer active joints and one fewer active enthesitis point. Patient‐reported pain improved from moderate/severe to mild. After 12 months, 54% of patients had active disease. CONCLUSION: The physician's decision to initiate a TNFi relied mostly on physical examination findings. Despite improvement in arthritis, enthesitis, and patient‐reported pain at 6 months post TNFi initiation, the majority of the patients still had active disease after 1 year of therapy.