The aim of clinical laboratories is to produce accurate and reproducible results to enable effective and reliable clinical practice. The standard approach is to use both internal quality control (IQC) and external quality assessment (EQA). However, if specific issues are identified with IQC or EQA, it can be problematic to identify the exact nature of the problem.
As a result, we have developed an instant QA solution for CD4+ T lymphocyte counting, termed VERIQAS™. The exact composition of the panel changes over time, but each panel consists of 20 stabilised samples with predefined CD4+ T lymphocyte counts that span low clinically relevant counts to normal counts and includes some blinded replicates (duplicates and/or quadruplicates). The CD4+ T lymphocyte target values for each specimen is defined to be trimmed mean + 2 trimmed standard deviations, where the trimmed values come from the CD4 count results reported by the approximately 700 labs that assay each UK NEQAS for Leucocyte Immunophenotyping send out. Laboratories that receive the VERIQAS™ panel return results on-line. Once a lab reports its results via a website, instant feedback is provided to both the participant and the EQA organisers, which enables the initiation of immediate targeted remedial action if required.
This approach can be used as a tool for pre-qualification, troubleshooting, training and instrument verification. Field trials with VERIQAS™ have shown that the panel can highlight problems such as pipetting and gating strategies that contribute to poor laboratory performance in a rapid and efficient manner.
Currently VERIQAS™ panels are provided on request, following discussions with UK NEQAS LI.