EFFECT OF ANALYTICAL RUN-LENGTH ON QUALITY-CONTROL (QC) PERFORMANCE AND THE QC PLANNING PROCESS

The performance measure traditionally used in the quality-control (QC) planning process is the probability of rejecting an analytical run wh en an out-of-control error condition exists. A shortcoming of this per formance measure is that it doesn't allow comparison of QC strategies that define analytical runs differently. Accommodating different analy tical run definitions is straightforward if QC performance is measured in terms of the average number of patient samples to error detection, or the average number of patient samples containing an analytical err or that exceeds total allowable error. By using these performance meas ures to investigate the impact of different analytical run definitions on QC performance demonstrates that during routine QC monitoring, the length of the interval between QC tests can have a major influence on the expected number of unacceptable results produced during the exist ence of an out-of-control error condition.