Real-World Analysis of Organ Transplantation-Specific Agent Based on Large Language Model in Post-Transplant Self-Management During Off-Hours: A Mixed-Methods Study.

OBJECTIVE: A significant gap exists in medical support for organ transplant patients during out-of-hours (OOH). General large language models (LLMs), affected by AI hallucinations, are unsuitable for complex post-transplant care. We built the first post-transplant AI agent based on LLMs to address these issues. METHODS: We constructed a specialized "post-transplant AI agent" (named Doctor Xiao Yi) and conducted a mixed-methods study comparing it to a hospital-wide general AI agent (named Nan Xiao Yi). Data included 20,176 real-world logs (June-December 2025) and a cross-sectional survey of 152 transplant patients. We examined patterns of use over time, the types of questions raised, and the factors influencing patient behavior. RESULTS: Unlike Nan Xiao Yi, Doctor Xiao Yi remained active during OOH, with a peak at 4:00 AM (P < 0.001). The general agent handled admin tasks like appointments, while the specialist agent provided clinical support such as diet, symptoms, and medication. Survey found 60.5% of OOH use by transplant patients due to reluctance to disturb human doctors. Furthermore, 63.8% of transplant patients were satisfied with the specialist agent's responses, and 48% reported they would decide on further hospital treatment based on AI suggestions. CONCLUSIONS: The specialist AI agent effectively fills the gap in medical and psychological services during OOH for transplant recipients. Based on the "dual-source knowledge base + GraphRAG + multi-agent framework" architecture, our specialist AI agent offers safe, reliable post-transplant care.