Legal Framework and Practical Challenges of Secondary Use of Medical Data in Japan

This paper examines the Japanese legal framework for the secondary use of medical data under the Next Generation Medical Infrastructure Act, focusing on how certified private entities practically implement secure data access. We describe a hybrid analysis model consisting of an on-site analysis center and a remote secure Virtual Desktop Infrastructure (VDI), designed to accommodate different legally defined user categories. By clarifying access conditions for anonymized and pseudonymized data, this study highlights how Japan's approach functionally aligns with the Health Data Access Body (HDAB) concept in the European Health Data Space, while addressing country-specific regulatory constraints. Key challenges include enabling user-provided analytical environments in a secure manner and adapting infrastructure to evolving legal requirements.