Reference Lab Quality Assessment for a High-Consequence Test

The quality of tests performed by reference laboratories should be regularly assessed as part of a functioning quality management program, since this testing has a direct impact on patients. Some reference lab quality assessment metrics include results integrity, turnaround time, and responsiveness to client needs. Test results may affect infection control practices. Highly sensitive, poorly specific tests for notifiable diseases are problematic from the infection control perspective. A positive result may not necessarily indicate that a notifiable disease is present, yet the possibility cannot be excluded without intense multidisciplinary investigation. We describe our experience with one such test. Our aim was to assess the frequency and impacts from preanalytical errors for one test provided by a reference lab to ultimately improve its clinical utility. A 12-month retrospective analysis was performed using data collected from the SoftLab LIS system. Sample rejection criteria were obtained from the reference lab website. In-house data were compared against rejection criteria to determine if and how preanalytical error impacted the reference lab results. Internal send-out procedures were also evaluated. No specimens were rejected by the reference lab, but 7 of 19 (36.8%) should have been rejected based on their criteria. Among these, four met one rejection criterion, two met two criteria, and one met three criteria. Of the suboptimal specimens, two had positive results (10.5% of total, 28.6% of suboptimal specimens). Among the 12 optimal specimens, one had a positive result (5.3% of total, 8.3% of optimal specimens). Our send-out area does not screen for reference lab rejection criteria. We identified evidence of preanalytical errors in a reference lab test. We have contacted the reference lab about this and modified our send-out practice for this test to prevent the inadvertent analysis of suboptimal specimens.