Tumor necrosis factor inhibitor prescribing and persistence by specialty in radiographic axial spondyloarthritis: a Korean claims study

Background/Aims: Although several studies have shown that specialist care may be associated with better outcomes, methodological limitations have made it difficult to draw definitive conclusions. Therefore, we examined real-world patterns of tumor necrosis factor inhibitor (TNFi) use for radiographic axial spondyloarthritis (r-axSpA) across prescribing specialties and compared TNFi retention between internal medicine and other departments using a nationwide claims database.Methods: Using Health Insurance Review and Assessment Service claims data (January 1, 2011 to June 30, 2022), we identified patients diagnosed with r-axSpA who initiated their first TNFi treatment. Baseline characteristics, TNFi retention by specialty and agent, and discontinuation risk were assessed. HRs for TNFi discontinuation were estimated using Cox proportional hazards models.Results: Among 5,944 TNFi initiators, 2,543 received adalimumab, 1,026 etanercept, 876 infliximab, and 1,499 golimumab. Most patients were treated in internal medicine (n = 5,102, 85.8%), followed by orthopedics (n = 622, 10.5%), neurosurgery (n = 185, 3.1%), and other departments (n = 35, 0.6%). TNFi retention was the highest in internal medicine. In multivariable analyses, the risk of discontinuation was higher in orthopedics (HR 1.24, 95% CI 1.11–1.37, <i>p</i> < 0.001), neurosurgery (HR 1.82, 95% CI 1.53–2.16, <i>p</i> < 0.001), and other departments than in internal medicine (HR 2.41, 95% CI 1.72–3.36, <i>p</i> < 0.001).Conclusions: TNFi retention was the highest in internal medicine, suggesting that care in this department may be associated with better treatment continuity in r-axSpA. Standardized management protocols and education may help optimize care across specialties.