Described herein are computer systems and methods for generating, in silico, one or more virtual patients. The one or more virtual patients can be used, for example, to conduct a virtual clinical trial, such as to determine an efficacy of a therapy or medical device. The one or more virtual patients mathematically represent a physiological system in an actual patient for a health condition. Also, the one or more virtual patients can be used, for example, to determine an adverse effect from a therapy or any other deviation from a therapy, or compliance of a patient suffering from a health condition on a therapeutic protocol.