Prothrombin time international normalized ratio monitoring by self-testing.
OBJECTIVE
The increasing numbers of patients on oral anticoagulants may challenge the traditional organization of patient monitoring. The availability of portable coagulometers capable of measuring prothrombin time (PT) international normalized ratio (INR) in a drop of capillary blood facilitates decentralization of monitoring by self-testing. This article reviews the literature on use of portable coagulometers.


RESULTS
Numerous studies have evaluated the reliability of portable coagulometers in testing the PT-INR. This has been assessed by statistically as well as clinically relevant criteria. Other studies have been devoted to developing calibration models fulfilling the criteria recommended by the World Health Organization (WHO) for the calibration of INR measuring systems. Finally, studies have assessed the value of schemes for patient training and for the long-term quality assurance of portable coagulometers.


CONCLUSIONS
It can be concluded from the published studies that PT-INR self-testing may be considered as a suitable alternative to conventional laboratory testing. For the PT-INR to be reliable, manufacturers of portable coagulometers should calibrate their devices against international standards for thromboplastin with procedures similar to those recommended by WHO for conventional measuring systems. Training of patients and implementation of appropriate quality assessment schemes are also essential prerequisites for the success of PT-INR self-testing.
Tripodi
Armando
A
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
D000284:Administration, Oral; D000925:Anticoagulants / Q000008:administration & dosage / Q000494:pharmacology; D006801:Humans; D019934:International Normalized Ratio / Q000295:instrumentation / Q000592:standards*; D010353:Patient Education as Topic; D011517:Prothrombin Time / Q000295:instrumentation / Q000592:standards*; D011785:Quality Assurance, Health Care; D015203:Reproducibility of Results; D012648:Self Care / Q000295:instrumentation*
D000925:Anticoagulants