The American Association for Clinical Chemistry (AACC) has recently launched an online continuing education program, “Practical Approaches to Quality Control in the Clinical Laboratory,” which is focused on guiding practicing clinical laboratorians through the principles and applications of good statistical QC practices. Courses in the program aim to explain how QC works, to identify and discuss the testing errors that interpretive rules are designed to detect, and to recommend appropriate investigational strategies for resolving QC failures.
Each course can be completed online in approximately 1 to 2 hours, and includes a lecture, slides and transcripts, and a quiz. Some of the courses also provide a list of recommended readings for further study. A recent Clinical Lab Products article summarizes each of the courses.
Nikola Baumann, Ph.D., Director of the Central Clinical Laboratory and Central Processing Laboratory at Mayo Clinic, presents the course, “Responses to Out-of-Control Situations."
Dr. Baumann identifies four steps that laboratories should consider when responding to a QC failure. “The first step is containment,” she says. “This means that when QC is outside of acceptable limits, the lab must immediately stop reporting patient results to contain the possible out-of-control situation. The second step is to verify that the QC failure truly represents an analytical out-of-control situation, or that the QC failure is ‘real.’ The third step is to investigate and troubleshoot. And the fourth step involves recovery. How do we go back in time and determine whether patient results were impacted by the out-of-control situation that just occurred?”
To complete the response to a QC failure, Dr. Baumann notes, “Regardless of the analytical performance of the method or the performance requirements for medical use, patient re-testing must always occur after QC failures.”
Dr. Baumann observes that little published guidance is available to help labs take this final step. “In general, the approach we want to take is to start repeat testing from the point in time of the QC failure, and then go back in time until the time that the error occurred. But the question remains: How do we determine the point in time that the error occurred, and how many patient samples need to be retested?”
Dr. Baumann ends her presentation with an extended discussion of how laboratories can assess the impact of a QC failure on patient test results and how to determine the number of patient samples that must be re-tested.