The Regulation for Medical exam of the Seafarer and Medical Institutions Article 8

Medical institutions are required to retain the data from seafarers’ medical examination and check-ups for at least 10 years for future reference.
中文原文 船員體格健康檢查及醫療機構指定辦法第8條
醫療機構應將船員體格檢查、健康檢查之資料整理留存備查至少十年。

English translation for reference only; the Chinese text prevails. Not legal advice.