An IQMH Proficiency Testing poster titled Comparison of anti-D titre results by conventional tube technique using non-identical versus identical indicator cells through a retrospective review of IQMH surveys was presented at the CSTM Conference 2022 by Chang-Keun (CK) Lee, IQMH Proficiency Testing Consultant Technologist, with the support of the Transfusion Medicine Scientific Committee.
The conference was held at the Westin Harbour Castle in Toronto, ON from May 26–29, and was attended by nurses, physicians, technologists, and others involved in Transfusion Medicine to share information, learn about the most recent developments in the field and appreciate one another’s contributions to providing effective transfusion therapy.
A summary of the poster can be seen below.
Download the poster to learn more.
Title: Comparison of anti-D titre results by conventional tube technique using non-identical versus identical indicator cells through a retrospective review of IQMH surveys
Authors: Chang-Keun Lee, Akash Gupta, Melanie Tokessy, Hakan Buyukdere, Sandra Bakker, Laura Aseltine
Introduction
There are many variables in antibody titration including a lack of method standardization. IQMH enabled a continuous quality improvement initiative by providing participants with titre indicator cells in Transfusion Medicine (TMED) Proficiency Testing (PT) surveys beginning in March 2021. The objective was to review the survey titre results between non-identical and identical indicator cells to assess the impact of indicator cells provision in conventional tube titration.
Design and Methods
Two TMED surveys from 2018 and 2021 with four anti-D titre challenge samples were selected to rule out high/low titre bias in the pre-implementation phase and to compare titre results between pre- and post-implementation.
Diluted serum ratio, incubation time, and technologists’ interpretation bias in the groups were not controlled among survey participants. To assess the statistical significance of indicator cells in titre variability, four one-tailed F-tests were performed between sample titre results after logarithmic conversion. A P-value of <0.05 was considered statistically significant.
Results
Overall, based on the P-value, intra-survey comparisons of low/high titre sample results in the pre- implementation phase were not significantly different (comparison group 1) but there was a statistically significant difference in the titre result comparisons between pre- and post-implementation of indicator cells (comparison groups 2, 3, and 4). Implementation of indicator cells provision led to a statistically significant decrease in variation in titre results.
Conclusions
Use of identical zygosity indicator cells in the titration method across laboratories led to a decrease in the interlaboratory variance of the titre results. The decrease in variance allows for better comparison of interlaboratory results when performing peer-to-peer comparisons and assessing laboratory performance. Improved assessment models can lead to accurate testing across laboratories that will enable consistent testing which can contribute to patient safety.