PACP regional quality control program: a general survey.

A regional quality control program operated by the Pennsylvania Association of Clinical Pathologists is described. About 120 laboratories in Pennsylvania and a few neighboring states participated in the program. Two 1000-liter lots of pooled normal and abnormal sera meeting or exceeding the specifications of the National Committee of Clinical Laboratory Standards and the College of American Pathologists were prepared and lyophilized. Participating laboratories determined each constituent in the sera every day for a year, from March 1973 to March 1974. The data was processed by a computer. The inter- and intra-laboratory reports containing the mean, standard deviation, coefficient of variation, Youden plots, etc. for each constituent were made available to all the participating laboratories. Practical applications of these statistical parameters in evaluating the quality of the performance of the laboratories are discussed.