A patient report generating system for receiving, storing and reporting medical test data for an entire patient population by periodically forming individual patient reports containing all test results for each patient for the total time period during which the patient has been a member of the patient population. Each report is organized to present the cumulative test data in a highly compact pattern of data packages wherein each data package includes only results of tests making up a particular organ system disease related subset of tests. The disclosed apparatus includes a data entry terminal, such as a keyboard input, for generating a digital electrical field for each test which field identifies the test, the test results, the date of the test and the patient. Also included is a random access memory for receiving and storing all signal fields and a high speed printer for forming a hard copy of the patient report from the stored data. To insure that each patient report is formatted identically with all other reports, the system includes a control memory for generating report and data package formatting signals which cause the printer to present the test data in consistent orthogonally arranged data packages wherein the test data within each data package is organized to assist the clinician to assimilate and understand the test data in the least possible time.