Microcomputer assisted hematology quality control using a modified average of normals program

A microcomputer based program package has been developed which utilizes a modified "average of normals" method to analyze data and monitor random and systematic error in the clinical hematology laboratory. The daily workload of normal patient values for leukocyte count, erythrocyte count, hemoglobin, mean corpuscular volume, prothrombin time, and activated partial thromboplastin time is entered through the keyboard and sorted by sex. The daily mean, standard deviation, standard error index, and F-ratio are then calculated for each test. Significant deviations from target values are automatically flagged. The system combines ease of data input with automatic statistical calculation, graphic display, and printout of the calculated data. The system has the capability of data analysis by shift, and incorporates cumulative sum, Trigg's tracking algorithm, and analysis of variance calculations. This statistical analysis had proven to be a sensitive indicator of random and systematic error in our laboratory and has allowed us to decrease the assay frequency of expensive commercial control material.