Contributions
Abstract: EP1183
Type: E-Poster Presentation
Session title: Quality of life, palliative care, ethics and health economics
Background
Point-of-care testing (POCT or bedside testing) provide faster results than those obtained in hospital laboratory analyzers, but should not compromise quality and safety. Compared to arterial and venous blood, capillary blood can be easily collected from the fingertip and does not require a skilled worker. Therefore, it has excellent potential as an ideal blood source for disease diagnosis and health monitoring. In coagulation, these systems are very useful in obtaining the INR test for the monitoring of vitamin K antagonist (VKA) oral anticoagulants therapy. Xprecia XtrideTM, Siemens®, is a POC system, with an ergonomic design, touch screen and intuitive software that, after performing an automatic calibration and two quality control checked on each test strip, provides INR after analyzing a sample of 6 μl of capillary blood, reporting data between 0.8 and 8. It uses Innovin® reagent with ISI 1. It is stablished that a POC device should be assessed for reproducibility against a central laboratory analyser, since INR is essential for proper management of oral anticoagulation. Regarding to NCCLS guidelines, statistically there is an equivalence of INRs obtained from POC systems that are within 0.4 at a target INR of 2.5 and 0.7 at a target INR of 3.5. Results exceeding an INR of 5.0 generally have reduced trueness, precision, and linearity, both in POC and laboratory-based testing.
Aims
This is a comparative study of INRs obtained by a POC system (POC-INR) compared to INRs obtained from plasma of venous samples collected in citrate tubes (P-INR), both from the same patient at the time. In previous studies of our own we found linearity between both methods and no statistically significant differences. In this study, our intention was to demonstrate if there was such correlation exclusively in supra-therapeutic INR results.
Methods
POC-INR was obtained from capillary sample analyzed with POC Xprecia XtrideTM, Siemens®. If INR was superior to 3.0, a venous citrated sample was recolected and P-INR was obtained from ACL-TOP500 hospital analyser, Werfen®, using as reagent Hemosil Recombiplastin® ISI 1. The results were compared with the statistical package Medcalc to calculate Pearson correlation coefficient and non-parametric Passing-Bablok regression analysis, suitable for method comparison studies.
Results
We obtained 215 samples of POC-INR higher than 3.0 and P-INR from the same patients at the time. A correlation coefficient r=0.7698 with a 95% confidence interval (0.7091 to 0.8192) was obtained, with the regression equation y=0.160 + 0.967 X, where y=P-INR, x=POC-INR: a=0.160 CI 95% (-0.4238 to 0.6581), b=0.9667 CI 95% (0.8762 to 1.0692) with a value of p=0.73, being evident that there are no significant differences regarding the deviation of the linearity between both techniques.
Conclusion
POCT Xprecia XtrideTM system, Siemens®, offers INR results statistically comparable to those obtained from plasma in a laboratory analyzer, even with supra-therapeutic INR values.
POCT allows the accessibility of the patient for the monitoring of VKA oral anticoagulant therapy; with the transmission of results via web, the decentralization of the control in the Health Centers is facilitated, allowing the validation and dosage from the hospital.
It offers a valid alternative to the historical pattern in which testing was mostly confined to the medical laboratory and provides continuous improvement in patient care quality.
Keyword(s): Anticoagulation, INR, Point-of-care
Abstract: EP1183
Type: E-Poster Presentation
Session title: Quality of life, palliative care, ethics and health economics
Background
Point-of-care testing (POCT or bedside testing) provide faster results than those obtained in hospital laboratory analyzers, but should not compromise quality and safety. Compared to arterial and venous blood, capillary blood can be easily collected from the fingertip and does not require a skilled worker. Therefore, it has excellent potential as an ideal blood source for disease diagnosis and health monitoring. In coagulation, these systems are very useful in obtaining the INR test for the monitoring of vitamin K antagonist (VKA) oral anticoagulants therapy. Xprecia XtrideTM, Siemens®, is a POC system, with an ergonomic design, touch screen and intuitive software that, after performing an automatic calibration and two quality control checked on each test strip, provides INR after analyzing a sample of 6 μl of capillary blood, reporting data between 0.8 and 8. It uses Innovin® reagent with ISI 1. It is stablished that a POC device should be assessed for reproducibility against a central laboratory analyser, since INR is essential for proper management of oral anticoagulation. Regarding to NCCLS guidelines, statistically there is an equivalence of INRs obtained from POC systems that are within 0.4 at a target INR of 2.5 and 0.7 at a target INR of 3.5. Results exceeding an INR of 5.0 generally have reduced trueness, precision, and linearity, both in POC and laboratory-based testing.
Aims
This is a comparative study of INRs obtained by a POC system (POC-INR) compared to INRs obtained from plasma of venous samples collected in citrate tubes (P-INR), both from the same patient at the time. In previous studies of our own we found linearity between both methods and no statistically significant differences. In this study, our intention was to demonstrate if there was such correlation exclusively in supra-therapeutic INR results.
Methods
POC-INR was obtained from capillary sample analyzed with POC Xprecia XtrideTM, Siemens®. If INR was superior to 3.0, a venous citrated sample was recolected and P-INR was obtained from ACL-TOP500 hospital analyser, Werfen®, using as reagent Hemosil Recombiplastin® ISI 1. The results were compared with the statistical package Medcalc to calculate Pearson correlation coefficient and non-parametric Passing-Bablok regression analysis, suitable for method comparison studies.
Results
We obtained 215 samples of POC-INR higher than 3.0 and P-INR from the same patients at the time. A correlation coefficient r=0.7698 with a 95% confidence interval (0.7091 to 0.8192) was obtained, with the regression equation y=0.160 + 0.967 X, where y=P-INR, x=POC-INR: a=0.160 CI 95% (-0.4238 to 0.6581), b=0.9667 CI 95% (0.8762 to 1.0692) with a value of p=0.73, being evident that there are no significant differences regarding the deviation of the linearity between both techniques.
Conclusion
POCT Xprecia XtrideTM system, Siemens®, offers INR results statistically comparable to those obtained from plasma in a laboratory analyzer, even with supra-therapeutic INR values.
POCT allows the accessibility of the patient for the monitoring of VKA oral anticoagulant therapy; with the transmission of results via web, the decentralization of the control in the Health Centers is facilitated, allowing the validation and dosage from the hospital.
It offers a valid alternative to the historical pattern in which testing was mostly confined to the medical laboratory and provides continuous improvement in patient care quality.
Keyword(s): Anticoagulation, INR, Point-of-care