Performance and practice in UK hospital transfusion laboratories

The two main sources of data for assessment of performance and practice are external quality assessment (EQA) and haemovigilance. In the UK both have their limitations, but are broadly representative of UK-wide clinical practice. Data from the Serious Hazards of Transfusion scheme (SHOT), show that approximately 30% of errors occur in the laboratory. ABO grouping errors are of particular concern, and were the cause of one death and one case of serious morbidity during 2004. Laboratory practice is changing, with an increase in the use of column agglutination technology (CAT) and automation, and a consequent increase in abbreviated testing. Transcription and transposition errors are a continual problem, particularly in manual systems and are responsible for many reports to SHOT as well as in EQA. Reagent selection and result interpretation play a major part in D typing errors seen in UK NEQAS exercises, with anti-CDE and potentiated anti-D reagents responsible for mistyping of rr cells. EQA results show some lack of understanding and knowledge with respect to antibody identification, with errors occurring due to inappropriate pattern matching, with no consideration given to masked antibodies. UK NEQAS data show that performance has improved enormously over the decades, but errors are still occurring in all parts of the process.