Final answer:
The type of medical record system where patient information is kept together by subject matter is the subject-based medical record system.
Step-by-step explanation:
The type of medical record system in which patient information is kept together by subject matter is the subject-based medical record system. In this system, patient information is organized and stored based on the specific medical condition or subject area. For example, all information related to a patient's cardiovascular health will be kept together in one section, while information about their mental health will be kept in another section.