Identifying Factors Associated with Biologic Therapy Initiation in Severe Asthma: A Real-World Case-Control Study Using SHI Claims Data

Background: Biologic therapies (Bx) represent a substantial advance for severe uncontrolled asthma, yet real-world determinants of initiation remain insufficiently defined. Objective: To examine demographic, clinical, healthcare utilization, and regional factors associated with Bx initiation in German statutory health insurance (SHI) data. Methods: Retrospective case–control study using anonymized SHI claims (2010–2023; 7.8M insured). Patients≥12 years with severe asthma and a newly documented uncontrolled episode were included. Cases initiated a Bx; controls were non-initiators matched on index quarter and follow-up. Multivariable logistic regression estimated odds ratios (OR, 95% CI). Sensitivity analyses applied alternative exposure windows. Results: 9,179 patients met criteria (839 initiators; 8,340 controls). Initiators were younger (mean 53 vs 58 y) and less frequently female (53.6% vs 59.6%). Independent predictors of higher initiation included eosinophilic granulomatosis with polyangiitis (EGPA, OR 35.65; p