1. A computer-implemented method for applying a dimensionality reduction process to a medical data set, comprising: obtaining a data set stored in a medical database, the data set including a set of medical data entries relating to medical events for individuals in a population; identifying a collection of the set of medical data entries relating to a common medical event for an individual in the population for replacement by a representative medical data entry for the common medical event, the identifying including identifying medical data entries of the set that are associated with medical events relating to the common medical event and occurring within a predetermined period of time; and reducing the size of the medical database by: replacing the identified collection of medical data entries with the representative medical data entry for the common medical event in the medical database, the representative medical data entry including a numerical indicator representing a number of the medical data entries in the identified collection; and eliminating the identified collection of medical data entries from the medical database.