title: Quality assurance program for whole blood prothrombin time-international normalized ratio point-of-care monitors used for patient self-testing to control oral anticoagulation.
abstract: Whole blood coagulation monitors are increasingly used for patient self-testing to control oral anticoagulation, but there are no comprehensive quality assurance (QA) programs to check their performance. We report on the experience with one of such programs applied in a field study where patients on prothrombin time (PT)-international normalized ratio (INR) self-testing were asked to bring their monitors to the anticoagulation clinic for checking. PT-INR testing was performed three times over 3 months with 14 patient's monitors and test strips on three recalcified QA plasmas by an experienced laboratory operator. Each patient was also asked to perform PT-INR self-testing (his/her own capillary blood) which was then compared to the laboratory PT-INR (plasma). Overall, the comparison between the observed and the consensus PT-INR on QA plasmas was acceptable with the majority of measurements lying within +/-15% or 20% of the consensus values. The comparison between the PT-INR self-testing and the laboratory method was also acceptable: overall, there was no statistical significant difference between the mean PT-INR values and the majority of paired measurements were less than 15% or 20% apart. In conclusion, our results show that the proposed QA scheme is feasible and may be implemented on a larger scale. Monitors should be recalled periodically to the clinic where they have been prescribed to the patient. During each visit, the clinic may check the monitors and patient self-testing performance as described. Such comprehensive QA system would make monitoring of oral anticoagulant treatment by self-testing safer and more effective.
authors.affiliation: Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Department of Internal Medicine, University and IRCCS Maggiore Hospital, Via Pace 9, 20122 Milan, Italy. armando.tripodi@unimi.it
authors.forename: Armando
authors.initials: A
authors.lastname: Tripodi
authors.forename: Caterina
authors.initials: C
authors.lastname: Bressi
authors.forename: Monica
authors.initials: M
authors.lastname: Carpenedo
authors.forename: Veena
authors.initials: V
authors.lastname: Chantarangkul
authors.forename: Marigrazia
authors.initials: M
authors.lastname: Clerici
authors.forename: Pier Mannuccio
authors.initials: PM
authors.lastname: Mannucci
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage* / Q000494:pharmacology; D032921:Consensus; D005260:Female; D006801:Humans; D019934:International Normalized Ratio / Q000295:instrumentation / Q000592:standards*; D007753:Laboratories / Q000592:standards; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation / Q000592:standards*; D019095:Point-of-Care Systems / Q000592:standards*; D011517:Prothrombin Time / Q000295:instrumentation / Q000592:standards*; D011785:Quality Assurance, Health Care; D011786:Quality Control; D012648:Self Care / Q000295:instrumentation*
chemical_list: D000925:Anticoagulants