Accuracy of the CoaguChek XS for point-of-care international normalized ratio (INR) measurement in children requiring warfarin

2008 ◽  
Vol 99 (06) ◽  
pp. 1097-1103 ◽  
Author(s):  
Karina Black ◽  
Mary Massicotte ◽  
Michelle Bauman ◽  
Stefan Kuhle ◽  
Susan Howlett-Clyne ◽  
...  

SummaryPoint-of-care INR (POC INR) meters can provide a safe and effective method for monitoring oral vitamin K antagonists (VKAs) in children. Stollery Children’s Hospital has a large POC INR meter loan program for children requiring oral VKAs. Our protocol requires that POC INR results be compared to the standard laboratory INR for each child on several consecutive tests to ensure accuracy of CoaguChek XS® (Roche Diagnostics, Basel Switzerland) meter. It was the objective of the study to determine the accuracy of the CoaguChek XS by comparing whole blood INR results from the CoaguChek XS to plasma INR results from the standard laboratory in children. POC INR meter validations were performed on plasma samples from two time points from 62 children receiving warfarin by drawing a venous blood sample for laboratory prothrombin (PT)-INR measurements and simultaneous INR determinations using the POC-INR meter. Agreement between CoaguChek XS INR and laboratory INR was assessed using Bland-Altman plots. Bland-Altman's 95% limits of agreement were 0.11 (-0.20; 0.42) and 0.13 (-0.22; 0.48) at the two time points, respectively. In conclusion, the CoaguChek XS meter appraisal generates an accurate and precise INR measure in children when compared to laboratory INR test results.

2020 ◽  
Vol 120 (04) ◽  
pp. 687-691
Author(s):  
Majed A. Refaai ◽  
Vinay Shah ◽  
Ronald Fernando

Abstract Introduction There are limited publications about the microINR point-of-care (POC) system (iLine Microsystems). The current microINR POC system was compared with the ACL TOP 500 laboratory analyzer (Instrumentation Laboratory) and with the CoaguChek XS POC system (Roche Diagnostics). Methods This study was performed at three United States medical centers. Sixty-eight nonanticoagulated normal donors and 245 warfarin anticoagulated patients were included. Testing was performed in duplicate using capillary blood samples for the POC systems and venous blood samples for the laboratory testing. Accuracy and imprecision were assessed. Results Comparing microINR to ACL revealed a correlation coefficient (r) of 0.973, a slope of 1.00 (95% confidence interval [CI], 0.97–1.03), and an intercept of 0.08 (95% CI, 0.04–0.15). When compared with the CoaguChek XS, r was 0.977 with a slope of 0.92 (95% CI, 0.89–0.94) and an intercept of 0.15 (95% CI, 0.08–0.19). Predicted bias values at international normalized ratio (INR) 2.0, 3.5, and 4.5 were ≤ 5% against both references. Agreement with ACL was 97, 95, and 100% for the INR ranges of < 2.0 ± 0.40, 2.0 to 4.5 ± 20%, and ≥ 4.5 ± 25%, respectively. Agreement for the combined INR ranges was 96% against ACL and > 96% against the CoaguChek XS. The coefficient of variation of the microINR was 5.03% for INR < 2.0 and 4.68% for the therapeutic INR range 2.0 to 3.5. Conclusion The microINR results demonstrate adequate imprecision and accuracy to both ACL and CoaguChek XS. This indicates that monitoring INR by this microINR POC system is reliable and acceptable for the management of warfarin therapy.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mina Hur ◽  
Hanah Kim ◽  
Chul Min Park ◽  
Antonio La Gioia ◽  
Sang-Gyu Choi ◽  
...  

Background. Point-of-care testing (POCT) coagulometers are increasingly being used in the hospital setting. We investigated whether the prothrombin time international normalized ratio (INR) results by CoaguChek XS Plus (Roche Diagnostics GmbH, Mannheim, Germany) can be used reliably without being confirmed with the INR results by STA-R system (Diagnostica Stago S.A.S, Asnières sur Seine, France).Methods. A total of 118 INR measurements by CoaguChek XS Plus and STA-R were compared using Passing/Bablok regression analysis and Bland-Altman plot. Agreement of the INR measurements was further assessed in relation to dosing decision.Results. The correlation of INR measurements between CoaguChek XS Plus and STA-R was excellent (correlation coefficient = 0.964). The mean difference tended to increase as INR results increased and was 0.25 INR in the therapeutic range (2.0-3.0 INR). The overall agreement was fair to good (kappa = 0.679), and 21/118 (17.8%) INR measurements showed a difference in dosing decision.Conclusion. The positive bias of CoaguChek XS Plus may be obvious even in the therapeutic INR range, and dosing decision based on the CoaguChek XS Plus INR results would be different from that based on the STA-R results. The INR measurements by POCT coagulometers still need to be confirmed with the laboratory INR measurements.


2020 ◽  
Vol 318 (2) ◽  
pp. E184-E188 ◽  
Author(s):  
Jakob Norgren ◽  
Shireen Sindi ◽  
Anna Sandebring-Matton ◽  
Ingemar Kåreholt ◽  
Ulrika Akenine ◽  
...  

The ketone body β-hydroxybutyrate (BHB), assessed by a point-of-care meter in venous whole blood (BHBv), was used as the main outcome in a study on nutritional ketosis in healthy older adults. Two other BHB measures were also used in the study for validation and exploratory purposes, and here we report findings on correlation and agreement between those three methods. Ketosis in the range of 0–1.5 mmol/L was induced in 15 healthy volunteers by intake of medium-chain fatty acids after a 12-h fast. BHBv was assessed at 12 time points for 4 h. The same point-of-care meter was also used to test capillary blood (BHBc) at three time points, and a laboratory test determined total ketones (TK) in plasma (BHBp + acetoacetate) at four time points. A total of 180 cases included simultaneous data on BHBv, BHBc, BHBp, and TK. TK correlated with BHBp (Pearson’s r = 0.99), BHBv ( r = 0.91), and BHBc ( r = 0.91), all P < 0.0001. BHBv and BHBp had good agreement in absolute values. However, the slope between BHBc and BHBv, measured with the same device, was in the range of 0.64–0.78 in different regression models, indicating substantially higher BHB concentrations in capillary versus venous blood. We conclude that all three methods are valid to detect relative changes in ketosis, but our results highlight the importance of method considerations and the possible need to adjust cutoffs, e.g., in the management of ketoacidosis and in the evaluation and comparison of dietary interventions.


2015 ◽  
Vol 114 (12) ◽  
pp. 1260-1267
Author(s):  
Joseph S. Biedermann ◽  
Marieke J. H. A. Kruip ◽  
A. M. H. P. van den Besselaar

SummaryMany patients treated with vitamin K antagonists (VKA) determine their INR using point-of-care (POC) whole blood coagulation monitors. The primary aim of the present study was to assess the INR within-subject variation in self-testing patients receiving a constant dose of VKA. The second aim of the study was to derive INR imprecision goals for whole blood coagulation monitors. Analytical performance goals for INR measurement can be derived from the average biological within-subject variation. Fifty-six Thrombosis Centres in the Netherlands were invited to select self-testing patients who were receiving a constant dose of either acenocoumarol or phenprocoumon for at least six consecutive INR measurements. In each patient, the coefficient of variation (CV) of INRs was calculated. One Thrombosis Centre selected regular patients being monitored with a POC device by professional staff. Sixteen Dutch Thrombosis Centres provided results for 322 selected patients, all using the CoaguChek XS. The median within-subject CV in patients receiving acenocoumarol (10.2 %) was significantly higher than the median CV in patients receiving phenprocoumon (8.6 %) (p = 0.001). The median CV in low-target intensity acenocoumarol self-testing patients (10.4 %) was similar to the median CV in regular patients monitored by professional staff (10.2 %). Desirable INR analytical imprecision goals for POC monitoring with CoaguChek XS in patients receiving either low-target intensity acenocoumarol or phenprocoumon were 5.1 % and 4.3 %, respectively. The approximate average value for the imprecision of the CoaguChek XS, i. e. 4 %, is in agreement with these goals.


2019 ◽  
Vol 14 (5) ◽  
pp. 883-889
Author(s):  
William D. Arnold ◽  
Kenneth Kupfer ◽  
Randie R. Little ◽  
Meera Amar ◽  
Barry Horowitz ◽  
...  

Background: Point-of-care (POC) hemoglobin A1c (HbA1c) testing has advantages over laboratory testing, but some questions have remained regarding the accuracy and precision of these methods. The accuracy and the precision of the POC Afinion™ HbA1c Dx test were investigated. Methods: Samples spanning the assay range were collected from prospectively enrolled subjects at three clinical sites. The accuracy of the POC test using fingerstick and venous whole blood samples was estimated via correlation and bias with respect to values obtained by an NGSP secondary reference laboratory (SRL). The precision of the POC test using fingerstick samples was estimated from duplicate results by calculating the coefficient of variation (CV) and standard deviation (SD), and separated into its components using analysis of variance (ANOVA). The precision of the POC test using venous blood was evaluated from samples run in four replicates on each of three test cartridge lots, twice per day for 10 consecutive days. The SD and CV by study site and overall were calculated. Results: Across the assay range, POC test results from fingerstick and venous whole blood samples were highly correlated with results from the NGSP SRL ( r = .99). The mean bias was −0.021% HbA1c (−0.346% relative) using fingerstick samples and −0.005% HbA1c (−0.093% relative) using venous samples. Imprecision ranged from 0.62% to 1.93% CV for fingerstick samples and 1.11% to 1.69% CV for venous samples. Conclusions: The results indicate that the POC test evaluated here is accurate and precise using both fingerstick and venous whole blood.


BMJ Open ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. e036147
Author(s):  
Lindsey K Reif ◽  
Marie Elmase Belizaire ◽  
Grace Seo ◽  
Vanessa Rouzier ◽  
Patrice Severe ◽  
...  

IntroductionAdolescents living with HIV have poor antiretroviral therapy (ART) adherence and viral suppression outcomes. Viral load (VL) monitoring could reinforce adherence but standard VL testing requires strong laboratory capacity often only available in large central laboratories. Thus, coordinated transport of samples and results between the clinic and laboratory is required, presenting opportunities for delayed or misplaced results. Newly available point-of-care (POC) VL testing systems return test results the same day and could simplify VL monitoring so that adolescents receive test results faster which could strengthen adherence counselling and improve ART adherence and viral suppression.Methods and analysisThis non-blinded randomised clinical trial is designed to evaluate the implementation and effectiveness of POC VL testing compared with standard laboratory-based VL testing among adolescents and youth living with HIV in Haiti. A total of 150 participants ages 10–24 who have been on ART for >6 months are randomised 1:1 to intervention or standard arms. Intervention arm participants receive a POC VL test (Cepheid Xpert HIV-1 Viral Load system) with same-day result and immediate ART adherence counselling. Standard care participants receive a laboratory-based VL test (Abbott m2000sp/m2000rt) with the result available 1 month later, at which time they receive ART adherence counselling. VL testing is repeated 6 months later for both arms. The primary objective is to describe the implementation of POC VL testing compared with standard laboratory-based VL testing. The secondary objective is to evaluate the effect of POC VL testing on VL suppression at 6 months and participant comprehension of the correlation between VL and ART adherence.Ethics and disseminationThis study is approved by GHESKIO, Weill Cornell Medicine and Columbia University ethics committees. This trial will provide critical data to understand if and how POC VL testing may impact adolescent ART adherence and viral suppression. If effective, POC VL testing could routinely supplement standard laboratory-based VL testing among high-risk populations living with HIV.Trial registration numberNCT03288246.


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