PatientSim: A Persona-Driven Simulator for Realistic Doctor-Patient
  Interactions
Authors: name: Daeun Kyung, name: Hyunseung Chung, name: Seongsu Bae, name: Jiho Kim, name: Jae Ho Sohn, name: Taerim Kim, name: Soo Kyung Kim, name: Edward Choi
Organization: KAIST AI

Doctor-patient consultations require multi-turn, context-aware communication
tailored to diverse patient personas. Training or evaluating doctor LLMs in
such settings requires realistic patient interaction systems. However, existing
simulators often fail to reflect the full range of personas seen in clinical
practice. To address this, we introduce PatientSim, a patient simulator that
generates realistic and diverse patient personas for clinical scenarios,
grounded in medical expertise. PatientSim operates using: 1) clinical profiles,
including symptoms and medical history, derived from real-world data in the
MIMIC-ED and MIMIC-IV datasets, and 2) personas defined by four axes:
personality, language proficiency, medical history recall level, and cognitive
confusion level, resulting in 37 unique combinations. We evaluated eight LLMs
for factual accuracy and persona consistency. The top-performing open-source
model, Llama 3.3, was validated by four clinicians to confirm the robustness of
our framework. As an open-source, customizable platform, PatientSim provides a
reproducible and scalable solution that can be customized for specific training
needs. Offering a privacy-compliant environment, it serves as a robust testbed
for evaluating medical dialogue systems across diverse patient presentations
and shows promise as an educational tool for healthcare.