CoaguChek XS PT Test Strips

AimsMany patients treated with vitamin K-antagonists (VKA) use point-of-care (POC) whole blood coagulometers for self-testing. The majority of patients in the Netherlands use one type of POC coagulometer, that is, the CoaguChek XS. Each new lot of test strips for the CoaguChek XS is validated by a group of collaborating thrombosis centres. We assessed the International Normalised Ratio (INR) differences between each of 51 new lots of test strips and the International Standard for thromboplastin rTF/95 or its successor rTF/09.MethodsEach year, a particular lot of CoaguChek XS test strips was used as reference lot. The reference lot was validated by comparison to the International Standard, yielding a relationship between the reference lot INR and International Standard INR. Successive lots of test strips were compared to the reference lot by three centres using 19–29 capillary blood samples obtained from VKA-treated patients. Each patient provided two blood drops from the same finger prick, one for the reference lot strip and one for the new lot.ResultsThe mean INR differences between each lot and the International Standard varied between −8% and +4%. The mean absolute values of the relative differences varied between 2.4% and 8.1%. There were small but clinically unimportant differences in INR between the first and second drop of blood.ConclusionsAccuracy of CoaguChek XS INR determinations can be assessed by a group of collaborating centres using a limited number of capillary blood samples. As the mean INR differences with the International Standard were smaller than 10%, the lots were approved for use by the Netherlands Thrombosis Services.

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Clinical effects of calibration of CoaguChek XS PT Test Strips on Anticoagulation Management Services

Journal of the American Pharmacists Association ◽

10.1016/j.japh.2019.09.013 ◽

2020 ◽

Vol 60 (1) ◽

pp. 72-75

Author(s):

Marisa Trautsch ◽

Julia Nickerson-Troy ◽

Raechel Moore ◽

Elizabeth Ingari ◽

Nicole Meretsky ◽

...

Keyword(s):

Clinical Effects ◽

Anticoagulation Management ◽

Test Strips ◽

Coaguchek Xs ◽

Management Services

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Accuracy assessment of consecutive test strip lots for whole blood INR point-of-care instruments: clarifying the role of frozen plasma pools

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2018-1054 ◽

2019 ◽

Vol 57 (9) ◽

pp. 1349-1357 ◽

Cited By ~ 2

Author(s):

Antonius M.H.P. van den Besselaar ◽

Charmane F. Abdoel ◽

Claudia J.J. van Rijn ◽

Felix J.M. van der Meer ◽

Christa M. Cobbaert

Keyword(s):

Whole Blood ◽

Accuracy Assessment ◽

Test Strip ◽

Positive Trend ◽

Accuracy Evaluation ◽

Blood Samples ◽

Test Strips ◽

International Standard ◽

Coaguchek Xs ◽

Frozen Plasma

Abstract Background In the Netherlands, each new lot of test strips for the CoaguChek XS is validated by a group of collaborating centers. The purpose of this study was to assess the accuracy of the international normalized ratio (INR) measured with consecutive test strip lots and the suitability of frozen plasma pools for accuracy evaluation. Methods Each year, a particular lot of CoaguChek XS test strips is used as reference lot. The reference lots have been validated with the International Standard for thromboplastin rTF/09, yielding a mathematical relationship (R1) between reference lot INR and International Standard INR. New lots are compared to the reference lot using patients’ capillary blood samples, yielding a relationship (R2) between the new lot INR and the reference lot INR. INRs of the blood samples were within the 1.5–4.5 interval. In parallel, three frozen plasmas pools are analyzed with the test strips. The distance of each plasma point to the line of relationship R2 was assessed. Results Fifty-four test strip lots have been evaluated during 3 years (2014–2016). Mean INR differences between test strip lot and International Standard rTF/09 varied between −0.14 and +0.20 (−4% and +8%, respectively). A positive trend with strip lot sequence number was observed (p<0.001). In several cases, the distance of the frozen plasmas to the whole blood relationship (R2) was greater than the critical value for commutability. Conclusions Using whole blood, all evaluated test strip lots met the analytical bias criterion of ±10%. Frozen plasma pools behave differently compared to whole blood and are not suitable for assessing absolute accuracy of new CoaguChek XS test strips.

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