UKAS Schedule of Accreditation, Accredited to ISO/IEC 17043:2010, Provider 7805
Measurement of fetomaternal haemorrhage for the purpose of prescribing prophylactic anti-D immunoglobulin to D negative pregnant women.
PURPOSE OF PROGRAMME:
To assess performance of clinical laboratories in screening and/or quantifying of fetomaternal haemorrhage in post-delivery D negative women (or post sensitising event during pregnancy), for the purpose of administering sufficient anti-D immunoglobulin to prevent sensitisation to the D antigen.
MATERIAL PROVIDED: Adult whole blood mixed with cord red cells.
DISTRIBUTIONS PER YEAR: 6
SAMPLES PER DISTRIBUTION: 2
FREQUENCY OF DISTRIBUTION: Bi-monthly, as per distribution schedule.
PROGRAMME OF ANALYSIS:
Results are entered online via the UK NEQAS Haematology and Transfusion website. Exercises are live for 7 days. Late results are only accepted if testing has been undertaken by the closing date and can be submitted by emailing a screenshot of the data entry page.
There are four different types of data analysis: a) a numerical score for accuracy of quantification; b) identification of grossly outlying results (for acid elution registrations only); c) identification of 'potential for sensitisation' errors (for acid elution registrations only); d) a numerical score for non-return or late return of results.
The analytical score is based on the deviation index (DI), which is calculated from the method median and a robust estimation of standard deviation. A score of <80 is considered satisfactory, 80 is borderline, and 100 is unsatisfactory. A grossly outlying result is defined as a DI outside the range of -2 to +3.5; each grossly outlying result receives one mark, shown as a single bar on a chart, and is defined as an episode of unsatisfactory performance. A potential for sensitisation error is
Participant performance for accuracy of quantification is measured for a rolling time window, where the score is based on the total of the DI values (ignoring the sign and rounding to a maximum of 3.5) for the last 6 scored samples, which is then multiplied by a constant. Grossly outlying results and potential for sensitisation errors are assessed over a rolling window of 3 exercises. The non-return score is cumulated over a rolling window of 3 exercises, and a score of 100 is defined as uns
PERSISTENT POOR PERFORMANCE:
This is defined as a) an analytical score of ≥100 and rising (or not falling), or a score of 100 on more than one discrete occasion in a 12 month period; b) more than one episode of unsatisfactory performance in 2 of 3 consecutive exercises.
Blood Transfusion Laboratory Practice
UK NEQAS for Blood Transfusion Laboratory Practice (BTLP) is the expert centre within the UK National External Quality Assessment Service (UK NEQAS) for all aspects of EQA relating to blood transfusion pre-transfusion and diagnostic testing, with around 300 UK and 700 international registrations and a further 2000 individual members in our web-based training and competency assessment tool (TACT). UK NEQAS (BTLP) provides EQA services for pre-transfusion testing, feto-maternal haemorrhage and ABO titration, with pilot schemes in progress for direct antiglobulin testing and red cell genotyping.