Abstract Number: PB0518
Meeting: ISTH 2020 Congress
Background: In May 2014 UK NEQAS BC introduced a POCD-dimer programme.n= 106
(Roche Cobas h232=67 and Quidel Triage=39).
Aims: To provide external quality assessment (EQA) to POC D-dimer testing.
Methods: Samples are lyophilised citrated plasma with a pre measured volume of diluent and a disposable pipette such that no laboratory equipment is needed. A patient scenario is also provided and users are required to choose either “no further investigation required” or “further investigation required” based on their local test result. This post analytical aspect is scored if there is a consensus of 80% or more . Peer group performance assessment is undertaken. Median values are calculated and the furthest 10% from the median (both higher and lower) are considered “outwith consensus”. If a centre has 3 outwith consensus surveys consecutively they will be classified as “persistently outwith consensus” and receive contact from the programme director.
Results: Results are shown in tables 1 and 2.A small number of centres have given interpretations that were inappropriate based on their results. One centre had a result of 0.74ug/ml FEU and stated “no further investigation”, manufacturers stated cut off is 0.5ug/ml FEU. For samples that were provided with a patient scenario of a Wells score of 3 or 4 a small number of centres stated no further investigation required. ie they had results of below the cut off but did not take into account the provided high Wells score.
Conclusions: EQA is essential for D-dimer testing whether in the laboratory or in a POC setting. The interpretations of these results overall was good but some centres did not take into account the patient scenario provided. We have also seen results which are over the manufacturers stated cut off which have been deemed by the user to not require further investigation.
| Table 1 Survey | Triage median ng/ml FEU | Triage interpretation | % Outwith consensus results | % Outwith consensus interpretation | CV% |
| 16 | 296 | 89.5% no further investigations | 8.7 | 10.5 | 17.4 |
| 17 | 443 | Not scored | 14.7 | not scored | 13.2 |
| 18 | 402 | Not scored | 16.1 | not scored | 23.4 |
| 19 | 1810 | 100% Further investigations | 18.9 | 0.0 | 25.2 |
| 20 | 597 | 88.9% Further investigations | 15.1 | 2.0 | 18.1 |
| 21 | 100 | 93.3% no further investigations | 0.0 | 6.7 | Not applicable |
| 22 | 357 | Not scored | 15.2 | Not scored | 27.4 |
| 23 | 1400 | 100% Further investigations | 17.1 | 0.0 | 17.5 |
[Table 1 Data shown for the last 2 years for Triage users]
| Table 2 Survey | Cobas h232 median ug/ml FEU | Cobas h232 interpretations | % Outwith Consensus results | % Outwith Consensus interpretation | CV% |
| 16 | 0.25 | 89.9% No further investigations | 19.6 | 10.2 | 20.1 |
| 17 | 0.25 | 100% No further investigations | 14.5 | 0.0 | 17.3 |
| 18 | 0.23 | Not scored | 9.3 | not scored | 17.1 |
| 19 | 1.52 | 98% Further investigations | 16.7 | 2.0 | 23.4 |
| 20 | 0.36 | 92% No further investigations | 14.0 | 8.0 | 15.6 |
| 21 | 0.1 | 89.4% No further investigations | 1.9 | 10.6 | 31.5 |
| 22 | 0.37 | 91.5% No further investigations | 17 | 8.5 | 24.1 |
| 23 | 0.995 | 98% Further investigations | 18.3 | 2.0 | 19.7 |
[Table 2 Data shown for the last 2 years for Cobas h232 users]
To cite this abstract in AMA style:
Kitchen DP, Brown L, Munroe-Peart S, Lowe A, Jennings I, Kitchen S, Walker I. UK NEQAS for Blood Coagulation D-Dimer Point of Care Testing Programme: A Review of Data [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/uk-neqas-for-blood-coagulation-d-dimer-point-of-care-testing-programme-a-review-of-data/. Accessed October 1, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/uk-neqas-for-blood-coagulation-d-dimer-point-of-care-testing-programme-a-review-of-data/