Techniques presented herein disclose a method for generating a derived observation for a care plan assigned to a patient. According to one embodiment, an application executing on a care platform server receives an event log having a plurality of events. Each event includes one or more types of biometric data for the patient. The care plan includes one or more definitions for metrics that are derived from the one or more types of biometric data. A temporal slice of the event log is selected based on one or more of the definitions. The derived metrics are generated by evaluating events within the selected temporal slice of the event log against one or more of the definitions. A condition of the patient is evaluated based on the derived metrics.