A global quality control system to check PT‐INR portable monitor for Antivitamin K antagonists. (15th April 2014)

• Record Type: Journal Article
• Authors: Testa, S.; Paoletti, O.; Bassi, L.; Dellanoce, C.; Morandini, R.; Lippi, G.
• Is Part Of: International journal of laboratory hematology. Volume 37:Number 1(2015:Feb.)
• Page Start: 71
• Page End: 78
• Publication Date: 2014-04-15
• Subjects: Hematology -- Periodicals; Blood -- Diseases -- Periodicals; Hematology -- Periodicals; 616.15005
• DOI: 10.1111/ijlh.12239
• Languages: English
• ISSNs: 1751-5521

Abstract

<abstract abstract-type="main" id="ijlh12239-abs-0001"> <title>Summary</title> <sec id="ijlh12239-sec-0001" sec-type="section"> <title>Introduction</title> <p>Although most guidelines for quality assessment of INR PMs recommend specific procedures, no clear regulation or methodology is required for outpatients in our country. We have developed a specific INR portable monitor (PM) quality control system within our telemedicine organization to check over time quality performances and plan corrective actions.</p> </sec> <sec id="ijlh12239-sec-0002" sec-type="section"> <title>Methods</title> <p>Based on current guidelines for laboratory QC, the following aspects were assessed: suitability of PM, defined in terms of imprecision and accuracy; intra‐assay imprecision, defined according to monthly revision of Levey–Jennings cards with data from each peripheral healthcare unit (PHU), using an internal QC provided by the manufacturer (CV ± 20% considered as acceptable); quarterly accuracy study, for assessing agreement between analytical instruments, based on duplicate analysis of three samples with INR values reflecting different therapeutic ranges (differences ± 0.5 considered as acceptable); external quality assessment (NEQAS).</p> </sec> <sec id="ijlh12239-sec-0003" sec-type="section"> <title>Results</title> <p>In the nine PHU, 18 portable monitors were used to perform 22 929 test during year 2010. Analytical imprecision was low, showing CVs always <5%. Accuracy check showed two of 216 results out of range (0.92%), thus providing timely indication for instrument replacement. The external QC NEQAS showed optimal performance.</p> </sec> <sec id="ijlh12239-sec-0004" sec-type="section"> <title>Conclusion</title> <p>The current protocol for INR PMs quality assessment was effective to establish and maintain a reliable control of devices, ensuring the quality of analytical data over time. National authorities should be prompted to guarantee and apply correct protocols for INR‐PM use.</p> </sec> </abstract>