Poor Agreement among Prothrombin Time International Normalized Ratio Methods: Comparison of Seven Commercial Reagents

Abstract Background: Prothrombin time (PT) has long been the most popular test for monitoring oral anticoagulation therapy. The International Normalized Ratio (INR) was introduced to overcome the problem of marked variation in PT results among laboratories and the various recommendations for patient care. According to this principle, all reagents should be calibrated to give identical results and the same patient care globally. This is necessary for monitoring of single patients and for application of the results of anticoagulation trials and guidelines to clinical practice. Methods: We took blood samples from 150 patients for whom oral anticoagulation had been prescribed. Plasmas were separated and PTs determined by use of seven commercial reagents and four calibrator sets. The differences in results were assessed by plotting, for each possible pair of methods, the differences in INR values for each sample against the mean INR value (Bland-Altman difference plots). Results: Mean results differed significantly (P <0.001) for 17 of 21 possible paired comparisons of methods. Only two pairs of methods produced very similar results when assessed for problems of substantial differences in INR values; a significant, systematic increase in the difference with INR; and a significant systematic increase in the variation in difference with increasing INR values. Conclusions: The agreement among several (and perhaps most) commercial INR methods is poor. The failure of current calibration strategies may severely compromise both the monitoring of individual patients and the application of oral anticoagulation guidelines and trial results to clinical practice.

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Implementation of SintromacWeb®, a new internet-based tool for oral anticoagulation therapy telecontrol: Study on system consistency and patient satisfaction

Thrombosis and Haemostasis ◽

10.1160/th09-07-0469 ◽

2010 ◽

Vol 103 (05) ◽

pp. 1091-1101 ◽

Cited By ~ 10

Author(s):

Yolanda Mira ◽

María Teresa Contreras ◽

Cristina Aguado ◽

José Antonio Aznar ◽

Fernando Ferrando

Keyword(s):

Patient Satisfaction ◽

Oral Anticoagulation ◽

Point Of Care ◽

Anticoagulation Therapy ◽

International Normalized Ratio ◽

Final Visit ◽

Normal Range ◽

Oral Anticoagulation Therapy ◽

Self Testing ◽

Anticoagulated Patients

SummaryMost computer- or internet-assisted systems for oral anticoagulation therapy (OAT) telemanagement have limitations when it comes to implementation within a healthcare center. It was the objective of this study to evaluate convenience and patient satisfaction with the use of SintromacWeb→, a new OAT telecontrol system, compared with the conventional control. SintromacWeb® consists of a point-of-care device for patient international normalized ratio (INR) self-testing and software that allows internet mediated interaction with physicians. Patients initiated the use of SintromacWeb→ and were followed up during a three-month period. A score-based questionnaire was completed in three controlled visits, and data were subsequently analysed. A total of 102 patients were enrolled. At first visit, 55.7% of the patients had their INR within normal range, and 64.9% at the final visit. Internal consistency of the questionnaire was good (Cronbach‘s α: 0.79). Scores in the questionnaire were independent of patient’s age, education level, working status and INR value. The most valued features of SintromacWeb® were: fewer visits to the hospital, simplicity and convenience of the system, and time administration for control tasks (86.7%, 82.7% and 77.6% of very satisfied patients, respectively). Also, patients showed indifference or were dissatisfied with the conventional system. At the final visit, 99% of patients declared that they were satisfied with their OAT control. Moreover, all patients continued using Sintrom -acWeb→ after completion of the study. In conclusion, SintromacWeb→ telecontrol is a new model for management of anticoagulated patients. It was highly accepted and can be used by all patients regardless of their sociodemographic characteristics.

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The Impact of Using Mobile Applications on Health Outcomes in Patient Self-Management of Oral Anticoagulation Therapy

10.21203/rs.3.rs-179619/v1 ◽

2021 ◽

Author(s):

Hamid Moghaddasi ◽

Mohammadreza Naderi Haji ◽

Babak Sharif-Kashani ◽

Alireza Kazemi

Keyword(s):

Health Outcomes ◽

Therapeutic Range ◽

Oral Anticoagulation ◽

Mobile Applications ◽

Mobile Application ◽

Anticoagulation Therapy ◽

Self Management ◽

Oral Anticoagulation Therapy ◽

The Mean ◽

The Impact

Abstract Background Between one and two percent of the population of the developed countries are currently treated with oral anticoagulation therapy. The transition of all or part of the responsibility for therapy management to the patient is an appropriate strategy to respond increasing demand for oral anticoagulation therapy. The main objective of this original study was to investigate the impact of using mobile applications on health outcomes in patient self-management of oral anticoagulation therapy. Methods The papers reviewed in this study had two key characteristics: firstly, they were written in English, and secondly, they used mobile application in oral anticoagulation therapy. An Android mobile application called XrinA was developed to provide warfarin patient self-management. The study was conducted following a Before-After study design. In the Before and After periods, patients were treated as usual and by using the developed application, respectively. Results In the Before period, the mean percentage of International Normalized Ratios (INRs) within the therapeutic range and Time in Therapeutic Range (TTR) of patients was 31.63% and 34.4%, respectively. In the After period, the mean percentage of INRs within the therapeutic range and TTR of patients was 41.41% and 49.97%, respectively. In the After period, the mean INRs within the therapeutic range and the mean TTR increased by 9.78% and 15.57%, respectively. Conclusions Overall, the use of mHealth applications improved outcomes in patient self-management of oral anticoagulation therapy in terms of the percentage of INRs within the therapeutic range and TTR.

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Validation of the international normalized ratio (INR) in a new point-of-care system designed for home monitoring of oral anticoagulation therapy

International Journal of Laboratory Hematology ◽

10.1111/j.1751-553x.2007.00998.x ◽

2009 ◽

Vol 31 (1) ◽

pp. 20-25 ◽

Cited By ~ 34

Author(s):

W. PLESCH ◽

A. M. H. P. Van Den BESSELAAR

Keyword(s):

Oral Anticoagulation ◽

Point Of Care ◽

Anticoagulation Therapy ◽

Home Monitoring ◽

International Normalized Ratio ◽

Oral Anticoagulation Therapy ◽

Point Of Care System ◽

Care System

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IMPACT OF PHARMACIST LED ANTICOAGULATION MONITORING AND PATIENT EDUCATION ON ORAL ANTICOAGULATION THERAPY WITH ACENOCOUMAROL

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2017.v10i10.16459 ◽

2017 ◽

Vol 10 (10) ◽

pp. 314

Author(s):

Poojitha Reddy Reddy ◽

Omsri Mounika ◽

Gaddam Chandrika ◽

Aldrich Franklin ◽

Ramesh M ◽

...

Keyword(s):

Patient Education ◽

Drug Interactions ◽

Oral Anticoagulation ◽

Anticoagulation Therapy ◽

Therapeutic Index ◽

International Normalized Ratio ◽

Rank Test ◽

Oral Anticoagulation Therapy ◽

Before And After ◽

The Impact

Objective: Acenocoumarol is anoral anticoagulant with narrow therapeutic index, and the ideal dose of anticoagulation lies between International normalized ratio (INR) values of 2.0 and 3.5. Lack of monitoring and knowledge on acenocoumarol therapy may compromise patient’s safety resulting in under- or over-anticoagulation. A study was conducted to monitor for the safety of anticoagulation therapy, achievement of goal INR levels and to assess the impact of pharmacist led anticoagulation monitoring and patient education on the rational use of acenocoumarol in patients admitted in cardiology wards with thromboembolic disorders.Methods: The study was conducted in 70 patients; data collection was done, prescriptions were analyzed for drug-drug interactions and adverse drug reactions (ADRs). Patients’ knowledge on acenocoumarol therapy was assessed using a self-developed questionnaire at the baseline, then were subjected to a detailed patient education and on an average each patient received three sessions of education. They were again made to answer the same questionnaire on the day of discharge. The mean score of the responses before and after education was compared statistically using Wilcoxon signed rank test and McNemar test.Results: There were 60% patients under anticoagulated with the INR range of >2.0. 123 drug interactions were observed in 58 patients, on an average of 2 interactions per prescription, but no ADRs were observed. 59 patients (84.3%) showed significant overall improvement in knowledge on anticoagulation therapy following education.Conclusion: This study implies the role of clinical pharmacists in achieving better clinical outcomes in patients receiving oral anticoagulation therapy with acenocoumarol.

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Correction to: Elderly patients with atrial fibrillation in routine clinical practice: peri-procedural management of edoxaban oral anticoagulation therapy is associated with a low risk of bleeding and thromboembolic complications: a subset analysis of the prospective, observational, multinational EMIT-AF study

BMC Cardiovascular Disorders ◽

10.1186/s12872-021-01873-2 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

M. Unverdorben ◽

C. von Heymann ◽

A. Santamaria ◽

M. Saxena ◽

T. Vanassche ◽

...

Keyword(s):

Atrial Fibrillation ◽

Clinical Practice ◽

Elderly Patients ◽

Oral Anticoagulation ◽

Anticoagulation Therapy ◽

Routine Clinical Practice ◽

Low Risk ◽

Thromboembolic Complications ◽

Oral Anticoagulation Therapy ◽

Risk Of Bleeding

An amendment to this paper has been published and can be accessed via the original article.

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Comparison of a chromogenic factor X assay with international normalized ratio for monitoring oral anticoagulation therapy

Blood Coagulation & Fibrinolysis ◽

10.1097/mbc.0b013e328304e066 ◽

2008 ◽

Vol 19 (6) ◽

pp. 513-517 ◽

Cited By ~ 15

Author(s):

David L McGlasson ◽

Benjamin G Romick ◽

Bernard J Rubal

Keyword(s):

Oral Anticoagulation ◽

Anticoagulation Therapy ◽

International Normalized Ratio ◽

Factor X ◽

Oral Anticoagulation Therapy

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Level of protein C determined by combined assays during disseminated intravascular coagulation and oral anticoagulation

Blood ◽

10.1182/blood.v69.6.1704.1704 ◽

1987 ◽

Vol 69 (6) ◽

pp. 1704-1711 ◽

Cited By ~ 15

Author(s):

J Mimuro ◽

Y Sakata ◽

K Wakabayashi ◽

M Matsuda

Keyword(s):

Prothrombin Time ◽

Disseminated Intravascular Coagulation ◽

Oral Anticoagulation ◽

Protein C ◽

Solid Phase ◽

Anticoagulation Therapy ◽

Microtiter Plate ◽

Enzyme Linked Immunosorbent Assay ◽

Oral Anticoagulation Therapy ◽

Intravascular Coagulation

Abstract We have developed a variation of the solid-phase enzyme-linked immunosorbent assay (ELISA) to enable measurement of the activity and antigen levels of protein C (PC) in human plasma. With this assay it is possible to do both tests with the same sample and same microtiter plate coated with anti-PC monoclonal antibody (MCA)JTC-4, which inhibited neither activation of PC nor activity of activated PC (APC). Even in patients undergoing heparin treatment for severe disseminated intravascular coagulation, there were no detectable differences between amidolytic activity and antigen levels of PC in patients' plasma. In addition, there was a strong correlation between the immunologic levels of PC in patients' plasma determined both by polyclonal ELISA using peroxidase-labeled immunopurified antiprotein C-IgG and those found with MCA ELISA using peroxidase-labeled MCAJTC-5, which does not bind to APC. In contrast, when oral anticoagulation therapy was started, immunologic levels of plasma PC estimated by peroxidase-labeled MCAJTC- 1, a MCA that recognizes a gamma-carboxyglutamic acid domain-related conformational change of PC induced by metal ions, decreased more rapidly than did either the PC level determined by polyclonal ELISA or the percent prothrombin time. This suggested that comparison of MCAJTC- 1-recognized PC levels and prothrombin time may be necessary at the beginning of oral anticoagulation therapy to treat patients safely.

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Level of protein C determined by combined assays during disseminated intravascular coagulation and oral anticoagulation

Blood ◽

10.1182/blood.v69.6.1704.bloodjournal6961704 ◽

1987 ◽

Vol 69 (6) ◽

pp. 1704-1711

Author(s):

J Mimuro ◽

Y Sakata ◽

K Wakabayashi ◽

M Matsuda

Keyword(s):

Prothrombin Time ◽

Disseminated Intravascular Coagulation ◽

Oral Anticoagulation ◽

Protein C ◽

Solid Phase ◽

Anticoagulation Therapy ◽

Microtiter Plate ◽

Enzyme Linked Immunosorbent Assay ◽

Oral Anticoagulation Therapy ◽

Intravascular Coagulation

We have developed a variation of the solid-phase enzyme-linked immunosorbent assay (ELISA) to enable measurement of the activity and antigen levels of protein C (PC) in human plasma. With this assay it is possible to do both tests with the same sample and same microtiter plate coated with anti-PC monoclonal antibody (MCA)JTC-4, which inhibited neither activation of PC nor activity of activated PC (APC). Even in patients undergoing heparin treatment for severe disseminated intravascular coagulation, there were no detectable differences between amidolytic activity and antigen levels of PC in patients' plasma. In addition, there was a strong correlation between the immunologic levels of PC in patients' plasma determined both by polyclonal ELISA using peroxidase-labeled immunopurified antiprotein C-IgG and those found with MCA ELISA using peroxidase-labeled MCAJTC-5, which does not bind to APC. In contrast, when oral anticoagulation therapy was started, immunologic levels of plasma PC estimated by peroxidase-labeled MCAJTC- 1, a MCA that recognizes a gamma-carboxyglutamic acid domain-related conformational change of PC induced by metal ions, decreased more rapidly than did either the PC level determined by polyclonal ELISA or the percent prothrombin time. This suggested that comparison of MCAJTC- 1-recognized PC levels and prothrombin time may be necessary at the beginning of oral anticoagulation therapy to treat patients safely.

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