system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Case acts as its own control in which of the following study?
assistant
The correct answer is  Advantages of cross-over study design ( Cross over RCT): Each patient serves as his own control. All patients can be assured that they will receive the new therapy sometime during the course of investigation ( Thus, no ethical issues). Economize the total number of patients.