Long-Term Outcomes and Therapeutic Strategies for Newly Diagnosed Crohn's Disease in the Biologic Era: A Nationwide Claims-Based Study from Japan.

Introduction: Biological agents have been approved and are now widely used in the treatment of Crohn's disease (CD), fundamentally changing therapeutic strategies. However, evidence regarding long-term outcomes and treatment approaches-particularly in elderly onset (ED) and pediatric onset (PO) CD-remains limited. This study aimed to clarify the long-term prognosis and therapeutic patterns of patients newly diagnosed with CD using a nationwide real-world claims database in Japan. Methods: A retrospective cohort study was conducted using the DeSC Healthcare Inc. database, identifying 1,345 patients newly diagnosed with CD from 2014 to 2023. Patients were categorized by age at onset as pediatric (<16 years), elderly (≥65 years), and non-elderly/non-pediatric. Treatment strategies were classified as step-up or top-down based on the initial therapy. Kaplan-Meier analysis and log-rank tests were used to evaluate the cumulative rates of advanced therapy-free survival, steroid-free survival, and biological retention. Results: Of the 1,345 patients, 56 had PO and 472 had EO disease. Top-down therapy was used in 52.2% of cases. The 5-year advanced therapy-free and steroid-free rates were 57.2% and 44.2%, respectively. EO patients showed the highest advanced therapy-free rate (76.2%) and the lowest use of top-down therapy. PO patients had the lowest steroid-free rate and the highest top-down therapy (80%). Conclusions: Age at CD onset influences treatment strategies in Japan. Early biologic therapy is common in younger patients, whereas conservative approaches are preferred in older adults. Real-world data provide important insights for optimizing individualized CD management in the biological era.