Understanding clinical ordering practices: platelet antibody testing

Abstract

We use the platelet serum antibody test (Immucor Pak12G, Norcross, GA) for detection of alloantibodies with platelet and HLA class I specificity; whereas, we use the cell-bound platelet antibody test (Immucor Pak Auto, Norcross, GA) for detection of auto-antibodies with platelet glycoprotein specificity. We performed a retrospective audit to investigate when and how these tests were being ordered. All in-house serum and cell-bound platelet antibody testing between April 1st, 2014 and March 31st, 2015 were reviewed. Both results and clinical notes surrounding the time of order were reviewed. There were 208 serum platelet antibody tests performed during this time period with 11 repeats. There were 290 cell-bound platelet antibody tests performed during this time period with 13 repeats. Notably, both tests were ordered simultaneously 77 times. The clinical indication for all positive tests is listed in Table 1. The most likely specificities detected when both serum and cell-bound testing were ordered simultaneously are listed in Table 2. While each test appeared to be ordered most commonly for the appropriate reason, a number of tests were ordered for the incorrect clinical indication. Furthermore, because these tests are optimized to evaluate different clinical situations, simultaneous orders demonstrate a lack of understanding about test utility. 37% of serum platelet antibody tests and 26% of cell-bound platelet antibody tests were ordered together. Interestingly, the serum platelet antibody test had a number of orders for “other” reasons, which was predominantly due to lack of clinical documentation. In conclusion, an intervention to facilitate proper ordering practices is needed.Download : Download full-size imageDownload : Download full-size image