An alternative quality control procedure using the median patient seronegative response is presented.
Study design: Daily patient median responses were calculated for our Hepatitis B surface antigen, HepatitisB core antibody, Hepatitis C antibody and HIV antigen/antibody test systems. Because of the low prevalence of these viruses in our area, most patient responses are negative. A minimum of 5 patient samples per day was required to generate a stable daily median. Control limits were calculated and daily patient medians were plotted against commercial quality control results