Abstract: A computer system for determining a combined risk is disclosed. The computer system has a memory, at least one input device, and a central processing unit in communication with the memory and the at least one input device. The central processing unit obtains diagnostic data and identifies a plurality of models for analyzing the diagnostic data. The central processing unit also associates each model with one of a plurality of time periods and calculates, for each time period using the associated model, a predicted risk. Further, the central processing unit determines the combined risk based on the predicted risk for each time period.