A-369 Making sense of point of care coagulation testing

Abstract

Point of care (POC) prothrombin time (PT)/international normalized ratio (INR) testing can significantly enhance coagulation monitoring by increasing test access, improving therapeutic management and adherence, decreasing patient travel, increasing clinic throughput, and patient satisfaction. However, implementing POC PT/INR in the pediatric healthcare setting is complex and requires thoughtful consideration of technical and practical aspects of testing in a pediatric patient population, testing staff and their qualifications based on test complexity, quality control procedures, and instrument/test performance characteristics. In this study, we evaluated the performance metrics and operational/workflow implications for various POC PT/INR devices to adopt across a multi-site pediatric institution. POC PT/INR patient testing was performed across multiple devices (Table 1) including Coag-Sense, Abbott iSTAT, and Roche CoaguCHEK XS Plus and compared to the in-lab Werfen ACL Top 750 or 550 instruments. At the time of patients’ routine POC PT/INR testing, additional samples were voluntarily collected and performed on all additional testing platforms. Statistical analysis was performed with EP Evaluator. PT/INR device evaluation included precision studies, verification of the accuracy and linearity and correlation to in-lab methodology to ensure consistent results across the clinical enterprise. In addition, the POC devices were evaluated for ease of adoption in a pediatric outpatient setting. Coag-Sense precision study yielded a %CV of 3.6% for the low control at 23.4 seconds, and a %CV of 2.3% for the high control with a mean of 40.3 seconds. The accuracy and linearity of the Coag-Sense was verified from 0.9 to 5.20 using WP3 CAP survey material and a high patient sample. The correlation between the Coag-Sense and the in-lab method on the ACL Top (n=13) yielded a slope of 0.938, intercept 0.137, correlation coefficient (R) 0.9817, and a bias of 1.757% demonstrating excellent agreement with our in-laboratory method across the measuring range. Comparison between ACL Top and the Coagu CHEK XS Plus (n=9) yielded a slope of -0.226, intercept of 1.268, correlation coefficient (R) of -0.0563, and a bias of -0.322%. Comparisons between the CoaguCHEK XS Plus to Coag-Sense (n= 9) yielded a slope of 0.228, intercept of 0.80, correlation coefficient (R) 0.3430, and bias of 1.09%. The comparison of the Coag-Sense to i-STAT (n=17) yielded a slope of 0.763, intercept 0.42, correlation coefficient (R) 0.9779, bias 3.82%. Finally, the comparison of the i-STAT to ACL Top (n= 13) yielded a slope of 0.835, intercept of 0.299, correlation coefficient (R) of 0.9839 and bias of 4.470%. The Coag-Sense was selected as the ideal device of POC PT/INR testing based on ease-of-use and adoption to our existing outpatient workflow, waived regulatory status, and excellent correlation with our in-lab PT/INR test method.