Patient self-testing is a reliable and acceptable alternative to laboratory INR monitoring

Point-of-care testing, near-patient testing and patient self-testing: warning points

Point-of-care testing (POCT), near-patient testing (NPT) and patient self-tests (PST) are diagnostic examinations performed at the time and place of patient care. While POCT and NPT are performed and analyzed by medical professionals, PST are based on samples and parameters directly collected and analyzed by lay users. These tests are spreading both in high income countries and in low to middle income countries as they are expected to improve healthcare efficiency and equity, by saving resources, releasing pressure from hospitals and reducing logistical barriers. However, accurate multidisciplinary assessment is mandatory to ensure that what they promise is real. We reviewed some important ethical aspects, international standards and regulations. The current risks associated with alternative ways of testing are explained by the principles of respect for patient autonomy and non-maleficence. Further evidence from multidisciplinary assessment is needed to evaluate pros and cons in light of the principles of beneficence and justice. Although POCT or NPT need common regulation and accurate provider training to ensure safe and appropriate interpretation of results, PST needs even more attention as they are subject to direct patient use. Randomized controlled trails including patient education should be conducted in order to provide reliable evidence on clinical outcomes, patient acceptance and cost-effectiveness. Mandatory regulation is needed to avoid harm and EU regulation should help different countries maintain a safe use of devices in a global population of producers and users.

Accuracy and Precision of Point-of-Care International Normalized Ratio in Patients With Liver Disease

OBJECTIVE

To determine if the CoaguChek XS Pro Point-of-Care (POC) device can accurately and precisely measure the international normalized ratio (INR) compared with the gold standard laboratory INR in pediatric and adult patients with liver disease.

METHODS

This prospective cohort study included 15 pediatric patients without liver disease, 13 pediatric patients with liver disease, and 17 adult patients with liver disease. The accuracy of the POC INR values was determined using the correlation and Bland-Altman limits of agreement. The accuracy of the coagulometer INR was assessed by calculating the proportion of POC INR measurements that were ≤15% of their corresponding laboratory INR.

RESULTS

A comparison of INR measurements showed an excellent correlation in pediatric patients without liver disease ( r = 0.82), pediatric patients with liver disease ( r = 0.89), and adult patients with liver disease ( r = 0.96). Fourteen (93%) POC INR values were ≤15% in pediatric patients without liver disease from its paired laboratory INR. All 13 paired measurements were ≤15% in pediatric patients with liver disease. In adult patients with liver disease, 12 (71%) POC INR values were ≤15% of their paired laboratory INR.

CONCLUSIONS

In patients with liver disease, the CoaguChek XS Pro provides an accurate measure of the INR compared to laboratory INR measurements.

Point-of-care testing technologies for the home in chronic kidney disease: a narrative review

Point-of-care testing (POCT) performed by the patient at home, paired with eHealth technologies, offers a wealth of opportunities to develop individualized, empowering clinical pathways. The non-dialysis-dependent chronic kidney disease (CKD) patient who is at risk of or may already be suffering from a number of the associated complications of CKD represents an ideal patient group for the development of such initiatives. The current coronavirus disease 2019 pandemic and drive towards shielding vulnerable individuals have further highlighted the need for home testing pathways. In this narrative review we outline the evidence supporting remote patient management and the various technologies in use in the POCT setting. We then review the devices currently available for use in the home by patients in five key areas of renal medicine: anaemia, biochemical, blood pressure (BP), anticoagulation and diabetes monitoring. Currently there are few devices and little evidence to support the use of home POCT in CKD. While home testing in BP, anticoagulation and diabetes monitoring is relatively well developed, the fields of anaemia and biochemical POCT are still in their infancy. However, patients' attitudes towards eHealth and home POCT are consistently positive and physicians also find this care highly acceptable. The regulatory and translational challenges involved in the development of new home-based care pathways are significant. Pragmatic and adaptable trials of a hybrid effectiveness-implementation design, as well as continued technological POCT device advancement, are required to deliver these innovative new pathways that our patients desire and deserve.

Monitoring of anticoagulation in thrombotic antiphospholipid syndrome

Anticoagulation is central to the management of thrombotic antiphospholipid syndrome (APS). The standard anticoagulant treatment for thrombotic APS is life-long warfarin or an alternative vitamin K antagonist. The role of direct oral anticoagulants for thrombotic APS is not established due to the lack of definitive evidence and has recently been addressed in international guidance. Other anticoagulant options include low molecular weight heparin, unfractionated heparin, and fondaparinux. In APS patients, lupus anticoagulant can affect phospholipid-dependent coagulation monitoring tests, so that they may not reflect true anticoagulation intensity. Accurate assessment of anticoagulation intensity is essential, to optimize anticoagulant dosing and facilitate thrombus resolution; minimize the risk of recurrent thrombosis or bleeding; inform assessment of whether recurrent thrombosis is related to breakthrough thrombosis while on therapeutic anticoagulation, subtherapeutic anticoagulation, non-adherence, or spurious results; and guide the management of bleeding. Knowledge of anticoagulant intensity also informs assessment and comparison of anticoagulation regimens in clinical studies. Considerations regarding anticoagulation dosing and/or monitoring of thrombotic APS patients underpin appropriate management in special situations, notably APS-related severe renal impairment, which can occur in APS or APS/systemic lupus erythematosus-related nephropathy or catastrophic APS; and APS-related thrombocytopenia. Anticoagulant dosing and monitoring in thrombotic APS patients also require consideration in anticoagulant-refractory APS and during pregnancy. In this review, we summarize the tests generally used in monitoring anticoagulant therapy, use of the main anticoagulants considered for thrombotic APS, lupus anticoagulant effects on anticoagulation monitoring tests, and strategies for appropriate anticoagulant monitoring in thrombotic APS.

Benefit of Self-Managed Anticoagulation in Patients with Left Ventricular Assist Device

BACKGROUND

 The exact monitoring of the therapeutic-range international normalized ratio (INR) after left ventricular assist device (LVAD) implantation is an important aim to reduce the risk of thrombosis or bleeding complications. Service providers offer a telemedical anticoagulation service (CS).

METHODS

 We compared LVAD patients using the CS (n = 15) to those who received regular medical care (RMC; n = 15) to investigate if telemedicine supervision increased the INR-specific time in the therapeutic range (TTR) during anticoagulation. All patients received self-management training for phenprocoumon medication according to their INR value. INR values were documented for 12 months. A survey (scale: 1 = not satisfied and 10 = very satisfied) was used to determine patient's satisfaction and psychological well-being.

RESULTS

 A total of 1,798 INR measurements were analyzed. The TTR_Rosendaal was higher in patients undergoing RMC (78.1 ± 14.3%) compared with that in patients using the CS (58.3 ± 28.0%, p = 0.03). The patient's satisfaction with the coagulation setting at the beginning of the study (RMC: 6.7 ± 3.1, CS: 7.2 ± 3.0, p = 0.74) and psychological wellbeing (RMC: 6.5 ± 1.9, CS: 6.5 ± 2.7, p = 0.97) were comparable between both groups.

CONCLUSION

 We found that INR self-management is superior regarding the efficiency of post-LVAD anticoagulation therapy when compared with telemedical (CS)-based INR management in a small study cohort. Intensive training by experienced staff was able to replace CS.

Active surveillance with telemedicine in patients on anticoagulants during the national lockdown (COVID-19 phase) and comparison with pre-COVID-19 phase

BACKGROUND

The COVID-19 pandemic brought restriction to the movement of people due to the implementation of lockdown across various regions around the world. In India, most of the patients belong to rural areas and hence were unable to come for a follow-up visit. Hence, we reached out to patients on oral anticoagulation using telemedicine with aim of communicating with the patient concerning drug compliance, titration of dose of anticoagulation, health education, and identification of high-risk patients needing referral to the nearest health facility/our institute. This study was conducted at the Hero DMC heart institute (a tertiary care center for cardiac diseases). The study design is cross-sectional and involves a comparison of the pre-COVID-19 phase with the COVID-19 phase. We asked a five-component (Likert scale) questionnaire from patients for satisfaction after the consult. All symptoms, need for hospitalization and clinical events were recorded. The events were compared in both groups.

RESULTS

We contacted 628 patients through telemedicine and 600 patients gave consent for participation in the study. For comparison, we analyzed data of 614 patients in the pre-COVID-19 phase. The mean age during the pre-COVID-19 phase was 55.27 + 17.09 years and the COVID-19 phase was 56.97 + 15.09 years with males more than females in both groups. There was no significant difference in the number of patients on oral anticoagulants and novel oral anticoagulants (NOAC). However, there were higher number of  patients on antiplatelets in the pre-COVID phase (p value0.01). 37% in the pre-COVID-19 phase and 40.31 % in the COVID-19 phase were noted to have out of target range INR (International normalized ratio). There was no difference in the number of bleeding or thromboembolic events seen. Patient response as assessed by a questionnaire (Likert scale) showed that >75% of patients were satisfied.

CONCLUSION

Through telemedicine, we were able to approach our patients on oral anticoagulation and achieved titration of anti-coagulation, and health education similar to pre-COVID-19 times. During pandemics, telemedicine offers a promising option for patient management with chronic cardiac conditions. It also provides us an opportunity for the management of patients on oral anticoagulation involving titration of drug dosages (anti-coagulation), identification of high-risk patients, and health education.

Management of Outpatient Warfarin Therapy amid COVID-19 Pandemic: A Practical Guide

Many healthcare resources have been and continue to be allocated to the management of patients with COVID-19. Therefore, the ongoing care of patients receiving oral anticoagulation with warfarin is likely to be compromised amid this unprecedented crisis. This article discusses a stepwise algorithm for the management of outpatient warfarin therapy. Alternative management strategies are presented and discussed, including alternative pharmacological therapy options and self-monitoring. Our algorithm aims to help clinicians safely optimize the treatment of patients requiring anticoagulation therapy in the context of the global response to the current pandemic.

Patient self-management of oral anticoagulation with vitamin K antagonists in everyday practice: clinical outcomes in a single centre cohort after long-term follow-up

Background

Patient self-management (PSM) of vitamin K antagonists (VKA) seems a very promising model of care for oral anticoagulation in terms of efficacy and safety. In comparison with other management models of VKA therapy, the number of scientific publications supporting the advantages of PSM is more limited. Currently, most of the scarce information comes from randomized clinical trials. Moreover, a small number of studies have assessed PSM of VKA therapy in real life conditions.

Methods

We analyzed clinical outcomes of 927 patients in a single center (6018.6 patient-years of follow-up). Recruitment took place between 2002 and 2017. All patients followed a structured training program, conducted by specialized nurses.

Results

Fifty percent of individuals had a mechanical heart valve (MHV), 23% suffered from recurrent venous thromboembolism (VTE) or high-risk thrombophilia, and 13% received VKA therapy because of atrial fibrillation (AF). Median follow-up was 6.5 years (range 0.1–15.97 years), median age was 58.1 years (IQR 48–65.9) and 46.5% were women. The incidence of major complications (either hemorrhagic or thromboembolic) was 1.87% patient-years (pt-ys) with a 95% CI of 1.54–2.27. The incidence of major thromboembolic events was 0.86% pt-ys (95% CI 0.64–1.13) and that of major hemorrhagic events was 1.01% pt-ys (95% CI 0.77–1.31). The incidence of intracranial bleeding was 0.22% pt-ys (95% CI 0.12–0.38). In terms of clinical indication for VKA therapy, the incidence of total major complications was 2.4% pt-ys, 2.0% pt-ys, 0.9% pt-ys and 1.34% pt-ys for MHV, AF, VTE and other (including valvulopathies and myocardiopathies), respectively. Clinical outcomes were worse in patients with multiple comorbidities, previous major complications during conventional VKA therapy, and in older individuals. The percentage of time in therapeutic range (TTR) was available in 861 (93%) patients. Overall, the mean (SD) of TTR was 63.6 ± 13.4%, being higher in men (66.2 ± 13.1%) than women (60.6 ± 13.2%), p < 0.05.

Conclusions

In terms of clinically relevant outcomes (incidence of major complications and mortality), PSM in real life setting seems to be a very good alternative in properly trained patients.

Microfluidics in Haemostasis: A Review

Haemostatic disorders are both complex and costly in relation to both their treatment and subsequent management. As leading causes of mortality worldwide, there is an ever-increasing drive to improve the diagnosis and prevention of haemostatic disorders. The field of microfluidic and Lab on a Chip (LOC) technologies is rapidly advancing and the important role of miniaturised diagnostics is becoming more evident in the healthcare system, with particular importance in near patient testing (NPT) and point of care (POC) settings. Microfluidic technologies present innovative solutions to diagnostic and clinical challenges which have the knock-on effect of improving health care and quality of life. In this review, both advanced microfluidic devices (R&D) and commercially available devices for the diagnosis and monitoring of haemostasis-related disorders and antithrombotic therapies, respectively, are discussed. Innovative design specifications, fabrication techniques, and modes of detection in addition to the materials used in developing micro-channels are reviewed in the context of application to the field of haemostasis.

Self-Ordering Laboratory Testing: Limitations When a Physician Is not Part of the Model

This review discusses considerations related to laboratory diagnostic testing purchased directly by consumers without the care and oversight of a medical doctor. There are necessary tensions between the patient, physician, laboratory medical professional (physician or scientist), laboratory as a corporate entity (where applicable), and manufacturers of diagnostic equipment. When the physician, in particular, the primary care physician, is removed from this relationship, there is a significant opportunity of exploitation of the patient. All downstream investigations following direct-to-consumer testing, including attendant risk, are offloaded onto the traditional medical system, caring physician(s), and patients themselves. This process places patients at risk of iatrogenic harm.

Verification of the qLabs international normalized ratio point-of-care device for monitoring of patients attending an anticoagulation clinic

INTRODUCTION

In the developing world, point-of-care (POC) testing for international normalized ratio (INR) plays an important role in the monitoring of patients on long-term warfarin therapy with limited access to healthcare ensuring safe and effective anticoagulation. A newly developed POC device for INR measurement by healthcare workers is the handheld qLabs POC device^® (Micropoint Biotechnologies Incorporated, Guangdong, China).

METHODS

The qLabs POC device^® was evaluated in 262 patients attending an anticoagulation clinic with regards to accuracy and precision of the INR results. The results were compared to the results obtained on the Stago STA R Max^® coagulation analyzer (Stago Diagnostica, Paris, France) on a wide range of normal and abnormal results of clinical relevance.

RESULTS

The mean laboratory INR (2.50 ± 1.08) was significantly higher than the qLabs POC device^® INR (2.38 ± 1.07) (P < .0001). The correlation coefficient (r) was .88, the slope coefficient was 1.0 (CI, 0.8-1.2), and the intercept was -0.10 (CI, -0.50 to 0.30). The mean of the differences was -0.13% (CI, -0.19 to -0.06). Dosage concordance was 85.46% and clinical agreement was 92.37%. However, clinical agreement was 42.42% in the subgroup above the target range (>3.5). The imprecision was within acceptable limits (<5%) and the error message rate was 4.38%.

CONCLUSION

In conclusion, the qLabs POC device^® is accurate and precise with high levels of dosage concordance and clinical agreement for INR values within and below the target range.

Cost-effectiveness analysis of patient self-testing therapy of oral anticoagulation

Patient Self-testing (PST) could be an option for present anticoagulation therapy monitoring, but current evidence on its cost-effectiveness is limited. This study aims to estimate the cost-effectiveness of PST to other different care approaches for anticoagulation therapy in Thailand, a low-to-middle income country (LMIC). A Markov model was used to compare lifetime costs and quality-adjusted life years (QALYs) accrued to patients receiving warfarin through PST or either anticoagulation clinic (AC) or usual care (UC). The model was populated with relevant information from literature, network meta-analysis, and database analyses. Incremental cost-effectiveness ratios (ICERs) were presented as the year 2015 values. A base-case analysis was performed for patients at age 45-year-old. Sensitivity analyses including one-way and probabilistic sensitivity analyses (PSA) were constructed to determine the robustness of the findings. From societal perspective, PST increased QALY by 0.87 and costs by 112,461 THB compared with UC. Compared with AC, PST increased QALY by 0.161 and costs by 21,019 THB. The ICER with PST was 128,697 (3625 USD) and 130,493 THB (3676 USD) per QALY gained compared with UC and AC, respectively. The probability of PST being cost-effective is 74.1% and 51.9%, compared to UC and AC, respectively, in Thai context. Results were sensitive to the efficacy of PST, age and frequency of hospital visit or self-testing. This analysis suggested that PST is highly cost-effective compared with usual care and less cost-effective against anticoagulation clinic. Patient self-testing strategy appears to be economically valuable to include into healthcare system within the LMIC context.

Electrochemical DNA-Based Immunoassay That Employs Steric Hindrance To Detect Small Molecules Directly in Whole Blood

The development of a universal sensing mechanism for the rapid and quantitative detection of small molecules directly in whole blood would drastically impact global health by enabling disease diagnostics, monitoring, and treatment at home. We have previously shown that hybridization between a free DNA strand and its complementary surface-bound strand can be sterically hindered when the former is bound to large antibodies. Here, we exploit this effect to design a competitive antibody-based electrochemical assay, called CeSHHA, that enables the quantitative detection of small molecules directly in complex matrices, such as whole blood or soil. We discuss the importance of this inexpensive assay for point-of-care diagnosis and for treatment monitoring applications.

An evaluation of a coagulation system (Xprecia Stride) for utilisation in anticoagulation management

AIM

To evaluate the reliability and performance of the Xprecia Stride coagulometer under the conditions in which it is most likely to be used.

METHODS

The performance of the Xprecia Stride coagulometer was compared with a local laboratory and the CoaguChek systems routinely used for international normalised ratio (INR) estimation within one primary and one secondary care based anticoagulation clinic in Birmingham. Anticoagulation clinic personnel were trained to use the Xprecia Stride. Patients attending the clinics were eligible if aged ≥18 years and had received warfarin for at least 3 months. Consenting participants provided capillary blood samples for parallel testing on the Xprecia Stride and CoaguChek systems. At the secondary care clinic, a venous blood sample was also collected for laboratory INR estimation. INR results were compared using linear regression analysis and Bland-Altman plots.

RESULTS

A total of 102 laboratory and 205 parallel coagulometer INR tests were performed. Linear regression revealed strong correlation between the Xprecia Stride and the laboratory (r=0.83) and between the Xprecia Stride and CoaguChek systems (r=0.92). Within the therapeutic range, agreement between the systems was very good with 87% of the Xprecia Stride and laboratory INR results and 93% of the Xprecia Stride and CoaguChek INR results being within 0.5 INR units of each other.

CONCLUSION

INRs tested using the Xprecia Stride system showed good agreement with the laboratory and CoaguChek systems. Findings indicate that in the hands of the intended users the Xprecia Stride is accurate, reliable and acceptable for use in a routine clinical setting.

The patients' perspective of international normalized ratio self-testing, remote communication of test results and confidence to move to self-management

AIMS AND OBJECTIVES

To elicit the perceptions of patients, who self-tested their international normalized ratio and communicated their results via a text or phone messaging system, to determine their satisfaction with the education and support that they received and to establish their confidence to move to self-management.

BACKGROUND

Self-testing of international normalized ratio has been shown to be reliable and is fast becoming common practice. As innovations are introduced to point of care testing, more research is needed to elicit patients' perceptions of the self-testing process.

DESIGN

This three site study used a cross-sectional prospective descriptive survey.

METHODS

Three hundred and thirty patients who were prescribed warfarin and using international normalized ratio self-testing were invited to take part in the study. The anonymous survey examined patient profile, patients' usage, issues, perceptions, confidence and satisfaction with using the self-testing system and their preparedness for self-management of warfarin dosage.

RESULTS

The response rate was 57% (n = 178). Patients' confidence in self-testing was high (90%). Patients expressed a high level of satisfaction with the support received, but expressed the need for more information on support groups, side effects of warfarin, dietary information and how to dispose of needles. When asked if they felt confident to adjust their own warfarin levels 73% agreed. Chi-squared tests for independence revealed that none of the patient profile factors examined influenced this confidence. The patients cited the greatest advantages of the service were reduced burden, more autonomy, convenience and ease of use. The main disadvantages cited were cost and communication issues.

CONCLUSION

Patients were satisfied with self-testing. The majority felt they were ready to move to self-management.

RELEVANCE TO CLINICAL PRACTICE

The introduction of innovations to remote point of care testing, such as warfarin self-testing, needs to have support at least equal to that provided in a hospital setting.

Effect of International Normalized Ratio monitoring at home versus the clinic on monitoring adherence in adults taking oral anticoagulant medications: a systematic review protocol

REVIEW QUESTION/OBJECTIVE

The objective of this review is to compare International Normalized Ratio (INR) monitoring adherence in two different settings: the outpatient INR clinic and the patient's home or residence. The review seeks to identify non-adherence trends in both settings to help providers determine which setting is best for patients on warfarin to improve INR monitoring adherence. Improved INR monitoring adherence correlates with maintaining routine INR testing.Specifically, the review question is what is the effect of home point-of-care INR monitoring compared to clinic monitoring on INR monitoring adherence in adults taking oral anticoagulant medications?

Policies and practices in haemostasis testing among laboratories in Croatia: a survey on behalf of a Working Group for Laboratory Coagulation of the Croatian Society of Medical Biochemistry and Laboratory Medicine

INTRODUCTION

The objective of this survey was to assess current policies and practice in haemostasis testing among both hospital and outpatient laboratories in Republic of Croatia.

MATERIALS AND METHODS

A questionnaire with seventy questions divided into nine sections was created in May 2015. Participants were asked about their practice related to test request form, sample collection, prothrombin time (PT) and activated partial thromboplastin time assays, other individual haemostasis assays, point-of-care testing (POCT), reporting of coagulation tests results and quality assurance of procedures, the personnel and other laboratory resources, as well as on issues related to education and implementation of additional coagulation assays in their laboratory. The survey was administered and data were collected between June and September 2015.

RESULTS

A total survey response rate was 104/170 (61.2%). Most respondents were faced with incomplete information on prescribed therapy and diagnosis on the test request or inappropriate samples withdrawn on distant locations, but also do not have protocols for handling samples with high haematocrit values. Reporting of PT-INR and D-dimer results was different between laboratories. Although almost all laboratories developed a critical value reporting system, reporting a value to general practitioners is still a problem. Result on coagulation POCT testing showed that not all devices were supervised by laboratories, which is not in compliance with Croatian Chamber of Medical Biochemistry acts.

CONCLUSION

Obtained results highlighted areas that need improvement and different practice patterns in particular field of haemostasis testing among laboratories. A harmonization of the overall process of haemostasis testing at national level should be considered and undertaken.

Comparing the clinical outcomes in patients with atrial fibrillation receiving dual antiplatelet therapy and patients receiving an addition of an anticoagulant after coronary stent implantation: A systematic review and meta-analysis of observational studies

BACKGROUND

Data regarding the clinical outcomes in patients with atrial fibrillation (AF) receiving dual antiplatelet therapy (DAPT) and an anticoagulant in addition to DAPT (DAPT + vitamin K antagonist [VKA]) after coronary stent implantation are still controversial. Therefore, in order to solve this issue, we aim to compare the adverse clinical outcomes in AF patients receiving DAPT and DAPT + VKA after percutaneous coronary intervention and stenting (PCI-S).

METHODS

Observational studies comparing the adverse clinical outcomes such as major bleeding, major adverse cardiovascular events, stroke, myocardial infarction, all-cause mortality, and stent thrombosis (ST) in AF patients receiving DAPT + VKA therapy, and DAPT after PCI-S have been searched from Medline, EMBASE, and PubMed databases. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to express the pooled effect on discontinuous variables, and the pooled analyses were performed with RevMan 5.3.

RESULTS

Eighteen studies consisting of a total of 20,456 patients with AF (7203 patients received DAPT + VKA and 13,253 patients received DAPT after PCI-S) were included in this meta-analysis. At a mean follow-up period of 15 months, the risk of major bleeding was significantly higher in DAPT + VKA group, with OR 0.62 (95% CI 0.50-0.77, P < 0.0001). There was no significant differences in myocardial infarction and major adverse cardiovascular event between DAPT + VKA and DAPT, with OR 1.27 (95% CI 0.92-1.77, P = 0.15) and OR 1.17 (95% CI 0.99-1.39, P = 0.07), respectively. However, the ST, stroke, and all-cause mortality were significantly lower in the DAPT + VKA group, with OR 1.98 (95% CI 1.03-3.81, P = 0.04), 1.59 (95% CI 1.08-2.34, P = 0.02), and 1.41 (95% CI 1.03-1.94, P = 0.03), respectively.

CONCLUSION

At a mean follow-up period of 15 months, DAPT + VKA was associated with significantly lower risk of stroke, ST, and all-cause mortality in AF patients after PCI-S compared with DAPT group. However, the risk of major bleeding was significantly higher in the DAPT + VKA group.

International normalized ratio self-testing and self-management: improving patient outcomes

Long term oral anti-coagulation with vitamin K antagonists is a risk factor of hemorrhagic or thromebomlic complications. Periodic laboratory testing of international normalized ratio (INR) and a subsequent dose adjustment are therefore mandatory. The use of home testing devices to measure INR has been suggested as a potential way to improve the comfort and compliance of the patients and their families, the frequency of monitoring and, finally, the management and safety of long-term oral anticoagulation. In pediatric patients, increased doses to obtain and maintain the therapeutic target INR, more frequent adjustments and INR testing, multiple medication, inconstant nutritional intake, difficult venepunctures, and the need to go to the laboratory for testing (interruption of school and parents’ work attendance) highlight those difficulties. After reviewing the most relevant published studies of self-testing and self-management of INR for adult patients and children on oral anticoagulation, it seems that these are valuable and effective strategies of INR control. Despite an unclear relationship between INR control and clinical effects, these self-strategies provide a better control of the anticoagulant effect, improve patients and their family quality of life, and are an appealing solution in term of cost-effectiveness. Structured education and knowledge evaluation by trained health care professionals is required for children, to be able to adjust their dose treatment safely and accurately. However, further data are necessary in order to best define those patients who might better benefit from this multidisciplinary approach.

Technology-assisted self-testing and management of oral anticoagulation therapy: a qualitative patient-focused study

BACKGROUND

Oral anticoagulation therapy requires regular blood testing to ensure therapeutic levels are maintained and excessive bleeding/clotting is avoided. Technology-assisted self-testing and management is seen as one of the key areas in which quality of care can be improved whilst reducing costs. Nevertheless, levels of patient engagement in self-testing and management remain low. To date, little research emphasis has been placed on understanding the patients' perspectives for low engagement. The typical approach adopted by healthcare providers is to provide patient education programmes, with the expectation that individual patients will change their behaviour and adopt new self-care strategies. However, if levels of patient engagement are to be increased, healthcare providers must also develop a better understanding of how their clinical service provision is perceived by patients and make adaptations.

OBJECTIVE

To explore patient views, needs and expectations of an anticoagulation service and the self-testing and management services provided.

METHODS

Interviews were conducted with 17 patients who currently engage in international normalised ratio (INR) self-testing and management. Thematic coding and analysis were carried out on the interview transcripts.

RESULTS

Four high-level themes emerged from interviews: (i) role of clinic, (ii) motivations for self-testing, (iii) managing INR and (iv) trust. The clinic was seen as adding value in terms of specifying testing frequency, dosage profiles and calibrating equipment. Prompt communication from clinic to patient was also valued, although more personalised/real-time communication would help avoid feelings of isolation. Patients felt more in control as self-tester/managers and often took decisions about treatment adjustments themselves. However, some also manipulated their own test results to avoid 'unnecessary' interventions.

CONCLUSIONS AND RECOMMENDATIONS

More personalised/real-time communication, pragmatic and collaborative patient-clinician partnerships and recognition of expert patient knowledge and expertise are needed if increased levels of engagement with self-testing and management service provision is to be realised.

Self-monitoring and self-management of oral anticoagulation

BACKGROUND

The introduction of point-of-care devices for the management of patients on oral anticoagulation allows self-testing by the patient at home. Patients who self-test can either adjust their medication according to a pre-determined dose-INR (international normalized ratio) schedule (self-management), or they can call a clinic to be told the appropriate dose adjustment (self-monitoring). Increasing evidence suggests self-testing of oral anticoagulant therapy is equal to or better than standard monitoring. This is an updated version of the original review published in 2010.

OBJECTIVES

To evaluate the effects on thrombotic events, major haemorrhages, and all-cause mortality of self-monitoring or self-management of oral anticoagulant therapy compared to standard monitoring.

SEARCH METHODS

For this review update, we re-ran the searches of the Cochrane Central Register of Controlled Trials (CENTRAL), 2015, Issue 6, the Cochrane Library, MEDLINE (Ovid, 1946 to June week 4 2015), Embase (Ovid, 1980 to 2015 week 27) on 1 July 2015. We checked bibliographies and contacted manufacturers and authors of relevant studies. We did not apply any language restrictions .

SELECTION CRITERIA

Outcomes analysed were thromboembolic events, mortality, major haemorrhage, minor haemorrhage, tests in therapeutic range, frequency of testing, and feasibility of self-monitoring and self-management.

DATA COLLECTION AND ANALYSIS

Review authors independently extracted data and we used a fixed-effect model with the Mantzel-Haenzel method to calculate the pooled risk ratio (RR) and Peto's method to verify the results for uncommon outcomes. We examined heterogeneity amongst studies with the Chi(2) and I(2) statistics and used GRADE methodology to assess the quality of evidence.

MAIN RESULTS

We identified 28 randomised trials including 8950 participants (newly incorporated in this update: 10 trials including 4227 participants). The overall quality of the evidence was generally low to moderate. Pooled estimates showed a reduction in thromboembolic events (RR 0.58, 95% CI 0.45 to 0.75; participants = 7594; studies = 18; moderate quality of evidence). Both, trials of self-management or self-monitoring showed reductions in thromboembolic events (RR 0.47, 95% CI 0.31 to 0.70; participants = 3497; studies = 11) and (RR 0.69, 95% CI 0.49 to 0.97; participants = 4097; studies = 7), respectively; the quality of evidence for both interventions was moderate. No reduction in all-cause mortality was found (RR 0.85, 95% CI 0.71 to 1.01; participants = 6358; studies = 11; moderate quality of evidence). While self-management caused a reduction in all-cause mortality (RR 0.55, 95% CI 0.36 to 0.84; participants = 3058; studies = 8); self-monitoring did not (RR 0.94, 95% CI 0.78 to 1.15; participants = 3300; studies = 3); the quality of evidence for both interventions was moderate. In 20 trials (8018 participants) self-monitoring or self-management did not reduce major haemorrhage (RR 0.95, 95% CI, 0.80 to 1.12; moderate quality of evidence). There was no significant difference found for minor haemorrhage (RR 0.97, 95% CI 0.67 to 1.41; participants = 5365; studies = 13). The quality of evidence was graded as low because of serious risk of bias and substantial heterogeneity (I(2) = 82%).

AUTHORS' CONCLUSIONS

Participants who self-monitor or self-manage can improve the quality of their oral anticoagulation therapy. Thromboembolic events were reduced, for both those self-monitoring or self-managing oral anticoagulation therapy. A reduction in all-cause mortality was observed in trials of self-management but not in self-monitoring, with no effects on major haemorrhage.

Correlation Between Home INR and Core Laboratory INR in Patients Supported with Continuous-Flow Left Ventricular Assist Devices

It has been well established that patient self-testing (PST) of international normalized ratio (INR) using home monitoring devices increases the average therapeutic time and patient satisfaction. Long-term anticoagulation therapy with warfarin is used in patients with continuous-flow left ventricular assist device (CF-LVAD) to minimize the occurrence of thromboembolic events; however, PST devices have never been tested in patients with CF-LVADs. The purpose of this study was to determine the reliability of the PST device Alere INRatio 2 in patients supported with CF-LVADs. A correlation study was performed in 50 patients with CF-LVAD who were on stable warfarin therapy for a minimum of 3 weeks. Simultaneous INR values were determined from capillary whole blood samples using the Alere PST device and venous blood samples processed in the core laboratory at Columbia University Medical Center. There was a moderate correlation between the venous and the capillary INR values with a correlation coefficient of 0.83. The median difference between the methods was 0.39, with 44 of 50 patients recording higher INRs with Alere. Results remained unchanged after adjusting for use of amiodarone, abnormal hematocrit and liver enzymes, creatinine, and thyroid-stimulating hormone. Point of care testing with Alere correlates moderately well but consistently overestimates INR when compared with conventional laboratory testing in patients with CF-LVAD.

The clinical effectiveness and cost-effectiveness of point-of-care tests (CoaguChek system, INRatio2 PT/INR monitor and ProTime Microcoagulation system) for the self-monitoring of the coagulation status of people receiving long-term vitamin K antagonist therapy, compared with standard UK practice: systematic review and economic evaluation

BACKGROUND

Self-monitoring (self-testing and self-management) could be a valid option for oral anticoagulation therapy monitoring in the NHS, but current evidence on its clinical effectiveness or cost-effectiveness is limited.

OBJECTIVES

We investigated the clinical effectiveness and cost-effectiveness of point-of-care coagulometers for the self-monitoring of coagulation status in people receiving long-term vitamin K antagonist therapy, compared with standard clinic monitoring.

DATA SOURCES

We searched major electronic databases (e.g. MEDLINE, MEDLINE In Process & Other Non-Indexed Citations, EMBASE, Bioscience Information Service, Science Citation Index and Cochrane Central Register of Controlled Trials) from 2007 to May 2013. Reports published before 2007 were identified from the existing Cochrane review (major databases searched from inception to 2007). The economic model parameters were derived from the clinical effectiveness review, other relevant reviews, routine sources of cost data and clinical experts' advice.

REVIEW METHODS

We assessed randomised controlled trials (RCTs) evaluating self-monitoring in people with atrial fibrillation or heart valve disease requiring long-term anticoagulation therapy. CoaguChek(®) XS and S models (Roche Diagnostics, Basel, Switzerland), INRatio2(®) PT/INR monitor (Alere Inc., San Diego, CA USA), and ProTime Microcoagulation system(®) (International Technidyne Corporation, Nexus Dx, Edison, NJ, USA) coagulometers were compared with standard monitoring. Where possible, we combined data from included trials using standard inverse variance methods. Risk of bias assessment was performed using the Cochrane risk of bias tool. A de novo economic model was developed to assess the cost-effectiveness over a 10-year period.

RESULTS

We identified 26 RCTs (published in 45 papers) with a total of 8763 participants. CoaguChek was used in 85% of the trials. Primary analyses were based on data from 21 out of 26 trials. Only four trials were at low risk of bias. Major clinical events: self-monitoring was significantly better than standard monitoring in preventing thromboembolic events [relative risk (RR) 0.58, 95% confidence interval (CI) 0.40 to 0.84; p = 0.004]. In people with artificial heart valves (AHVs), self-monitoring almost halved the risk of thromboembolic events (RR 0.56, 95% CI 0.38 to 0.82; p = 0.003) and all-cause mortality (RR 0.54, 95% CI 0.32 to 0.92; p = 0.02). There was greater reduction in thromboembolic events and all-cause mortality through self-management but not through self-testing. Intermediate outcomes: self-testing, but not self-management, showed a modest but significantly higher percentage of time in therapeutic range, compared with standard care (weighted mean difference 4.44, 95% CI 1.71 to 7.18; p = 0.02). Patient-reported outcomes: improvements in patients' quality of life related to self-monitoring were observed in six out of nine trials. High preference rates were reported for self-monitoring (77% to 98% in four trials). Net health and social care costs over 10 years were £7295 (self-monitoring with INRatio2); £7324 (standard care monitoring); £7333 (self-monitoring with CoaguChek XS) and £8609 (self-monitoring with ProTime). The estimated quality-adjusted life-year (QALY) gain associated with self-monitoring was 0.03. Self-monitoring with INRatio2 or CoaguChek XS was found to have ≈ 80% chance of being cost-effective, compared with standard monitoring at a willingness-to-pay threshold of £20,000 per QALY gained.

CONCLUSIONS

Compared with standard monitoring, self-monitoring appears to be safe and effective, especially for people with AHVs. Self-monitoring, and in particular self-management, of anticoagulation status appeared cost-effective when pooled estimates of clinical effectiveness were applied. However, if self-monitoring does not result in significant reductions in thromboembolic events, it is unlikely to be cost-effective, based on a comparison of annual monitoring costs alone. Trials investigating the longer-term outcomes of self-management are needed, as well as direct comparisons of the various point-of-care coagulometers.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013004944.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Patient perceptions and expectations of an anticoagulation service: a quantitative comparison study of clinic-based testers and patient self-testers

BACKGROUND

Government initiatives see the provision of technology-assisted self-care as one of the key areas in which there is capacity for improving quality of care whilst reducing costs. However, levels of patient engagement in self-testing and management (STM) remain low. Little emphasis has been placed on understanding the patients' perspectives of the reasons for this limited engagement. Typically, patient engagement in STM is achieved via the provision of patient education programmes, which aim to enable patients to make the changes necessary to become competent self-carers. However, placing the onus to change on the individual patient is unrealistic. If levels of patient engagement are to be improved, patient needs and expectations of clinical services must be better understood and service provision must be adapted accordingly.

OBJECTIVE

Explore patient perceptions and expectations of clinical service provision and their views of having and making choices about care.

METHODS

Participants [N = 191, 103 patient self-tester managers (PSTMs) and 87 clinic-based testers (CBTs)] completed the SERVQUAL and ChQ instruments to capture perspectives on service quality and choice, respectively. A comparative statistical analysis explored the similarities and differences between PSTMs' and CBTs' responses.

RESULTS

Clinic-based testers' perceptions of service quality were significantly more positive than PSTMs', as were their expectations of the 'tangible' aspects of service delivery. PSTMs' expectations of service quality were significantly higher than their perceptions. PSTMs attributed significantly more value to making choices compared with CBTs.

CONCLUSIONS AND RECOMMENDATIONS

To close the gap between PSTMs expectations and perceptions of service quality and better cater for their choice preferences, service providers may benefit from taking into account the following practice considerations: maintain frequent, timely, personalised and direct interactions with PSTMs; prioritise investment in resources to facilitate patient/practitioner interaction over tangible facilities; ensure that PSTMs are given the opportunity to make choices about their care.

Assessing the utility of an online registry for patients monitoring their own warfarin therapy

AIMS

To evaluate the utility of an online self-report registry for patient self-monitoring and self-management (PSM) of warfarin therapy.

METHODS

A prospective observational study of UK-based patients undertaking PSM and recording their international normalised ratio (INR) data via an online registry. Consenting participants recorded INR test dates, results and warfarin dosages using the online registry for a period of 12 months. Participants reported demographic data, disease characteristics and treatment-related adverse events and provided feedback via a survey. Data accuracy was assessed through comparison of INR results recorded online with results stored on 19 INR testing devices. Percentage time spent within therapeutic time in range (TTR) was also examined.

RESULTS

Eighty-seven per cent (39/45) completed the study period. Age ranged from 26 to 83 years, 44% had undertaken PSM for >5 years. Sixty-six per cent (25/38) reported that the registry was easy to navigate and use. Forty-two participants contributed a total of 1669 INR results. Agreement between self-reported INR results and source INR data was high (99%). Mean TTR was 76% (SD 18.58) with 83% having >60% TTR.

CONCLUSIONS

Findings suggest that an online PSM registry is feasible, accurate and acceptable to patients. These findings require confirmation in a larger cohort of PSM patients. An online self-report registry could provide a valuable resource for gathering real world evidence of clinical effectiveness and safety of these developing models of care.

Analytical performance of a point-of-care device in monitoring patients on oral anticoagulation with vitamin K antagonists

BACKGROUND

[Please check the following sentence for clarity: "Point-of-care devices measuring international normalized ratio have clinical appeal, reports of 'off-label' in-hospital/primary care use report improved time to intervention/dose adjustment."]Point-of-care devices measuring international normalized ratio have clinical appeal, reports of 'off-label' in-hospital/primary care use report improved time to intervention/dose adjustment. We evaluated the accuracy and precision of a device for such multiple patient use compared to a reference laboratory.

METHODS

The point-of-care international normalized ratio result of patients on oral anticoagulation at the Vascular Surgery clinic was compared to the reference to check for statistical and clinical correlation. This was a prospective case-control study design with sample size calculated for sensitivity of 87.5%, precision 5% and desired confidence level 95%.

RESULTS

There were 168 patients tested; 55% were male, the mean age was 45.4. Sixty per cent were in the target international normalized ratio range. Tests were done for statistical and clinical correlation. The international normalized ratio range using the point-of-care device was 0.8-7.5 (reference lab 0.8-10), mean international normalized ratio was 2.22 ± 1.6 (point-of-care device) compared to 2.46 ± 1.3 (reference lab). The mean absolute difference was 0.79 ± 0.92 and the mean relative difference was 8.1% ± 1.03. Data was analysed using a Bland-Altman plot yielding a mean of 0.738 (standard deviation 0.92). Concordance between the tests was 75% with r2 = 0.52 on linear regression. Using an error grid plot, excellent clinical correlation was seen in 63.8%. In 5.4% major corrective action was needed but potentially missed if relying on the point-of-care device.

CONCLUSION

The accuracy and precision of this point-of-care device is moderate. It may have potential utility only where access to a reference lab is difficult.

Is self-monitoring an effective option for people receiving long-term vitamin K antagonist therapy? A systematic review and economic evaluation

OBJECTIVES

To investigate the clinical and cost-effectiveness of self-monitoring of coagulation status in people receiving long-term vitamin K antagonist therapy compared with standard clinic care.

DESIGN

Systematic review of current evidence and economic modelling.

DATA SOURCES

Major electronic databases were searched up to May 2013. The economic model parameters were derived from the clinical effectiveness review, routine sources of cost data and advice from clinical experts.

STUDY ELIGIBILITY CRITERIA

Randomised controlled trials (RCTs) comparing self-monitoring versus standard clinical care in people with different clinical conditions. Self-monitoring included both self-management (patients conducted the tests and adjusted their treatment according to an algorithm) and self-testing (patients conducted the tests, but received treatment recommendations from a clinician). Various point-of-care coagulometers were considered.

RESULTS

26 RCTs (8763 participants) were included. Both self-management and self-testing were as safe as standard care in terms of major bleeding events (RR 1.08, 95% CI 0.81 to 1.45, p=0.690, and RR 0.99, 95% CI 0.80 to 1.23, p=0.92, respectively). Self-management was associated with fewer thromboembolic events (RR 0.51, 95% CI 0.37 to 0.69, p ≤ 0.001) and with a borderline significant reduction in all-cause mortality (RR 0.68, 95% CI 0.46 to 1.01, p=0.06) than standard care. Self-testing resulted in a modest increase in time in therapeutic range compared with standard care (weighted mean difference, WMD 4.4%, 95% CI 1.71 to 7.18, p=0.02). Total health and social care costs over 10 years were £7324 with standard care and £7326 with self-monitoring (estimated quality adjusted life year, QALY gain was 0.028). Self-monitoring was found to have ∼ 80% probability of being cost-effective compared with standard care applying a ceiling willingness-to-pay threshold of £20,000 per QALY gained. Within the base case model, applying the pooled relative effect of thromboembolic events, self-management alone was highly cost-effective while self-testing was not.

CONCLUSIONS

Self-monitoring appears to be a safe and cost-effective option.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42013004944.

Anticoagulation service: improving the referral process

Oral anticoaguIants are extremely common, and it is estimated that there are between 500,000 and 1 million people prescribed them in the UK.[1] These drugs are the most frequently named medication in fatal errors and litigation claims [2] and they require the implementation of additional safety controls.[3] Warfarin is the most commonly prescribed anticoagulant and it requires regular international normalised ratio (INR) monitoring and dosage adjustment to achieve the desired therapeutic range.[4] Under-anticoagulation can cause thrombosis and over-anticoagulation can lead to haemorrhage, both of which can be fatal.[5] At St. Peter's hospital there is an anticoagulation service providing regular international normalised ratio (INR) monitoring for patients on warfarin. However, the current referral system is paper-based and a baseline audit found that only 66% of patients were successfully referred to the service on discharge from hospital. This identifies a significant patient safety issue which could result in life-threatening consequences. An electronic referral form was developed within a pre-existing computer based ordering system with the aim of improving the referral rate. The electronic referral tool streamlined the referral process, making the form quicker and easier to fill out and removed the need for faxing lengthy paper forms. Key information on the form was made mandatory. After intervention a re-audit revealed that 84% of patients discharged on warfarin were referred to the clinic, which equates to an increase of 18%. The increased referral rate will improve patient safety and prevent unnecessary hospital admissions. There should be continued promotion of the importance of referring patients to the anticoagulation clinic. This can be delivered through inductions, teaching sessions, and re-audits. Future goals include an automated referral system triggered on patient discharge.

Comparison of prothrombin time derived from CoaguChek XS and laboratory test according to fibrinogen level

Background

CoaguChek XS is one of the most widely used point‐of‐care (POC) devices to evaluate prothrombin time for monitoring oral anticoagulant therapy. Unlike laboratory methods, it detects electrical signals produced by thrombin activity to derive the international normalized ratio (INR). Therefore, we hypothesized that laboratory methods and CoaguChek XS could produce different results according to fibrinogen level.

Methods

We compared INR values obtained from the CoaguChek XS and conventional laboratory method with 91 plasma samples covering a wide range of fibrinogen levels.

Results

The samples were stratified into low, mid, and high fibrinogen groups by fibrinogen levels of <130 mg/dl, 130–450 mg/dl, and >450 mg/dl, respectively. The mean INR difference of the low fibrinogen group was significantly different from that of the mid or high fibrinogen group (P < 0.001). In the low fibrinogen group, CoaguChek XS INR showed a negative bias compared with the laboratory INR, while the mid and high fibrinogen groups had positive bias.

Conclusion

Our results suggest that patient selection according to fibrinogen status should precede the implementation of POC testing using CoaguChek XS. Also, periodic comparisons between CoaguChek XS and laboratory INR results should be continued during the use of CoaguChek XS.

Self-management of oral anticoagulation

BACKGROUND

Properly dosed oral anticoagulation effectively prevents thromboembolic events. It is unclear whether adult patients with an indication for long-term oral anticoagulation can benefit from self-management in terms of patient-oriented endpoints and improved coagulation values.

METHOD

We selectively searched the Medline database for high-quality systematic reviews based on randomized controlled trials of self-measurement or self-management of oral anticoagulation, compared to standard treatment.

RESULTS

We identified eight review articles based on overlapping sets of ran - domized clinical trials. In all of these systematic reviews, patients who performed self-measurement or self-management had a 40% to 50% lower rate of thromboembolic events; in six of them, the mortality was also significantly lower, by 30% to 50%. Subgroup analysis revealed that these effects were present exclusively in patients who performed self-management, and not in those who only performed self-measurement. None of the review articles revealed any difference in the frequency of severe hemorrhagic events. Quality of life and patient satisfaction were rated in five reviews, which, however, used different instruments, with the result that no clear conclusions could be drawn. All of the review articles documented an improvement in coagulation values, but information on statistical significance was mostly lacking.

CONCLUSION

Adults with an indication for long-term oral anticoagulation benefit from self-management, as compared to standard treatment with management of dosing by a physician. A limitation of this study is that the multiple review articles on which it is based were largely analyses of the same group of clinical trials.

Successful management of anticoagulation therapy during international travel

Warfarin is considered a high-risk drug because of its narrow therapeutic window, variability in dose response, and multitude of drug and food interactions. Although travel advice is available for patients who are taking warfarin, it is geared toward patients who are traveling to developed countries and tends to be lacking in detail. We describe a 53-year-old woman with two mechanical heart valves and chronic atrial fibrillation who was taking warfarin for thromboembolism prophylaxis and had plans to travel to Vietnam for 10 weeks. Three days before her departure, she was prescribed amiodarone for long-term use. As a result of the extended duration of her travel and the complexities of warfarin use, the pharmacists who managed the patient's anticoagulation reviewed several aspects of a comprehensive management approach with the patient for a safe international trip. They assessed the patient's thromboembolic and hemorrhagic risks, and determined which other drugs (e.g., enoxaparin, phytonadione), dosages, and adequate supplies would be required along with warfarin, as well as how to safely transport these drugs during travel. In addition, the logistics of effectively monitoring international normalized ratio (INR) levels were evaluated, and methods of managing multiple potential scenarios were carefully planned out. Contact with the patient was made through pharmacist-directed telephone visits throughout the travel period. A total of 12 telephone visits were conducted with the patient during the 10 weeks of travel. Her INR was supratherapeutic on three occasions and was subtherapeutic once; however, neither enoxaparin nor phytonadione were needed during the travel period, and the patient returned safely to the United States. Effective and safe use of high-risk drugs for patients leaving the United States requires extensive pretravel planning, and pharmacists can play a central role in optimizing therapeutic outcomes for these patients during international travel.

A retrospective review of clinical international normalized ratio results and their implications

BACKGROUND

Warfarin is a key element in therapy for atrial fibrillation, deep venous thrombosis (DVT), stroke (cerebrovascular accident) and cardiac valve replacement. Often, patients' warfarin blood levels are not tightly controlled with regard to accepted therapeutic ranges, by virtue of the drug's unpredictable nature.

METHODS

The authors searched 16,017 active clinical charts for active patients of record from the three campuses of the School of Dentistry, Marquette University (MU), Milwaukee, for the years 2009 and 2010. Dental records of 315 patients contained entries including "INR," the abbreviation for the term "international normalized ratio." Only 247 of those records contained an indication of whether the patient's INR values were within therapeutic range. The authors found that 1.96 percent of the total MU dental clinic patient population had a history of warfarin use.

RESULTS

When the authors compared the INR values for patients with diagnoses of atrial fibrillation, DVT, stroke and cardiac valve replacement, they found that INR values for 107 of the 247 patients (43.3 percent) were not within therapeutic range for the respective diagnoses. For example, only 50 percent of the patients being treated for atrial fibrillation presented themselves for surgical dental treatment while their INR values were in tight control.

CONCLUSION

The INR values for a significant number of dental patients are not within the therapeutic range for their medical conditions. These patients need to seek follow-up care from their medical care providers.

CLINICAL IMPLICATIONS

Screening for INR in the dental office-especially before invasive dental treatment such as periodontal surgery, tooth extraction and dental implant placement-can help prevent postoperative complications. It also can aid the clinician in evaluating whether a patient's INR is within therapeutic range and, subsequently, whether the patient's physician needs to adjust the warfarin dosage.

Anticoagulation patient self-monitoring in the United States: considerations for clinical practice adoption

Systematic management models such as anticoagulation clinics have emerged in order to optimize warfarin effectiveness and to minimize related complications. Most of these models are structured so that patients come to a clinic for in-person testing and evaluation, thus making this model of care difficult to access and time consuming for many patients. The emergence of portable instruments for measuring anticoagulant effect in capillary whole blood made it possible for patients receiving warfarin to self-monitor the effect of their anticoagulant therapy. Self-monitoring empowers patients, offers the advantage of more frequent monitoring, and increases patient convenience by allowing testing at home and avoiding the need for frequent laboratory and clinic visits. Self-monitoring can entail patient self-testing (PST) and/or patient self-management (PSM). Several studies have evaluated and shown the benefit of both PST and PSM models of care when compared with either routine medical care or anticoagulation clinic management of anticoagulation therapy. Self-monitoring (PSM and/or PST) of anticoagulation results in lower thromboembolic events, lower mortality, and no increase in major bleeding when compared with standard care. Despite favorable results and enhanced patient convenience, the adoption of self-monitoring into clinical practice in the United States has been limited, especially in higher risk, disadvantaged populations. Although the emergence of a multitude of novel oral anticoagulants will permit clinicians to better individualize anticoagulant therapy options by choosing the optimum regimen based on individual patient characteristics, it is also expected that traditional agents will continue to play a role in a significant subset of patients. For those patients treated with traditional anticoagulants such as warfarin, future models of care will entail patient-centered management such as PST and PSM. The incorporation of technology (i.e., Web-based expert systems) is expected to further improve the outcomes realized by PST and PSM. Further studies are needed to explore factors that influence the adoption of self-monitoring in the United States and to evaluate the feasibility and implementation in real-life clinical settings.

Comparison of point-of-care testing (POCT): i-STAT(®) international normalized ratio (INR) vs reference laboratory INR in pediatric patients undergoing major surgery

BACKGROUND

The aim of the study was to compare international normalized ratio (INR) results obtained by point-of-care testing (i-STAT® device) with the reference laboratory INR in children undergoing major surgery with expected significant blood loss.

METHODS

  Pediatric patients undergoing craniofacial, spine, hip, or cancer surgery were included. Blood samples for coagulation testing were tested at several intraoperative time points and generally withdrawn from the arterial catheter, if accessible. A volume of 1.4 ml citrated blood was used for the reference laboratory INR test, and 0.1 ml of blood was taken for the whole blood INR test using the i-STAT® device. Blood samples for both tests were withdrawn at the same time and immediately analyzed with both devices.

RESULTS

A total of 169 paired blood samples were taken intraoperatively from 44 pediatric patients [IQR 0.9-10.7 years (median 3.3)]. Reference laboratory INR ranged from 0.96 to 3.43 (mean 1.40; sd 0.32) and INR of i-STAT® from 0.95 to 2.29 (mean 1.26; sd 0.22). The correlation coefficient was 0.83 (P < 0.001), and the bias values were 0.12 and 0.55 at the medical decision level of ≤2.0 and >2.0, respectively.

CONCLUSIONS

In the perioperative setting, point-of-care INR testing in children using the i-STAT® device is a reliable and easy-to-handle method for INR values ≤2.0, while INR values >2.0 might be underestimated.

The clinical significance of differences between point-of-care and laboratory INR methods in over-anticoagulated patients

INTRODUCTION

Patients receiving warfarin are at increased risk of bleeding when their International Normalised Ratio (INR) >4.5. Although not standardised above 4.5 the INR is measured in over-anticoagulated patients, consequently we have examined the reliability of INR results ≥4.5. We assessed: the relationship between different prothrombin time systems for INRs >4.5; the relationships between the INR and levels of vitamin K-dependent coagulation factors (VKD-CF) and thrombin generation test (TGT) parameters; and the impact that variation in results would have on warfarin dosing.

METHODS

INRs were performed using a CoaguChek XS Plus point-of-care (POC) device (measuring range 0.6-8.0). For POC INRs ≥4.5, laboratory INRs were also measured using a recombinant tissue factor (rTF) and a rabbit brain (RBT) thromboplastin.

RESULTS

There was good correlation between POC (INR ≥4.5, <8.0) and Lab INRs (rTF n=154, rs=0.87, p<0.0001; RBT n=102, rs=0.76, p<0.0001); and significant correlations between each of the VKD-CF and the INR, the strongest being with FVII (POC INR rs=-0.53 p<0.0001; Lab rTF-INR rs=-0.70 p<0.0001). TGT peak thrombin and ETP also showed good correlations with INR values (R(2)>0.71). Using POC and Lab rTF-INR, 109/154 (71%), or POC and Lab RBT-INR 75/102 (74%) results exhibited dosage concordance and/or were within 0.5 INR units. In the remaining patients variation in warfarin dosing was generally slight.

CONCLUSIONS

Our data suggest that CoaguChek XS Plus INRs >4.5 and <8.0 are comparable to laboratory INRs (both methods) and it is probably unnecessary to perform laboratory INRs for clinical management of patients with INRs >4.5 including those >8.0.

An anticoagulation safety program in home care: identifying areas for improvement with an educational program for registered nurses and physical therapists

The 2008 National Patient Safety Goal program, directed by the Joint Commission (TJC), mandated safety improvements for anticoagulation therapy. In response, an urban, not-for-profit, Medicare-certified hospital Home Health Department identified the need to evaluate the Home Healthcare anticoagulation standards, safety practices, and patient/staff educational processes and materials. This Home Healthcare entity shall be referred to as the Agency for the purposes of this article.

What are the basic self-monitoring components for cardiovascular risk management?

BACKGROUND

Self-monitoring is increasingly recommended as a method of managing cardiovascular disease. However, the design, implementation and reproducibility of the self-monitoring interventions appear to vary considerably. We examined the interventions included in systematic reviews of self-monitoring for four clinical problems that increase cardiovascular disease risk.

METHODS

We searched Medline and Cochrane databases for systematic reviews of self-monitoring for: heart failure, oral anticoagulation therapy, hypertension and type 2 diabetes. We extracted data using a pre-specified template for the identifiable components of the interventions for each disease. Data was also extracted on the theoretical basis of the education provided, the rationale given for the self-monitoring regime adopted and the compliance with the self-monitoring regime by the patients.

RESULTS

From 52 randomized controlled trials (10,388 patients) we identified four main components in self-monitoring interventions: education, self-measurement, adjustment/adherence and contact with health professionals. Considerable variation in these components occurred across trials and conditions, and often components were poorly described. Few trials gave evidence-based rationales for the components included and self-measurement regimes adopted.

CONCLUSIONS

The components of self-monitoring interventions are not well defined despite current guidelines for self-monitoring in cardiovascular disease management. Few trials gave evidence-based rationales for the components included and self-measurement regimes adopted. We propose a checklist of factors to be considered in the design of self-monitoring interventions which may aid in the provision of an evidence-based rationale for each component as well as increase the reproducibility of effective interventions for clinicians and researchers.

Self-monitoring and self-management of oral anticoagulation

BACKGROUND

The introduction of portable monitors (point-of-care devices) for the management of patients on oral anticoagulation allows self-testing by the patient at home. Patients who self-test can either adjust their medication according to a pre-determined dose-INR schedule (self-management) or they can call a clinic to be told the appropriate dose adjustment (self-monitoring). Several trials of self-monitoring of oral anticoagulant therapy suggest this may be equal to or better than standard monitoring.

OBJECTIVES

To evaluate the effects of self-monitoring or self-management of oral anticoagulant therapy compared to standard monitoring.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 4), MEDLINE, EMBASE and CINAHL (to November 2007). We checked bibliographies and contacted manufacturers and authors of relevant studies. No language restrictions were applied.

SELECTION CRITERIA

Outcomes analysed were thromboembolic events, mortality, major haemorrhage, minor haemorrhage, tests in therapeutic range, frequency of testing, and feasibility of self-monitoring and self-management.

DATA COLLECTION AND ANALYSIS

The review authors independently extracted data. We used a fixed-effect model with the Mantzel-Haenzel method to calculate the pooled risk ratio (RR) and Peto's method to verify the results for uncommon outcomes. We examined heterogeneity amongst studies with the Chi(2) and I(2) statistics.

MAIN RESULTS

We identified 18 randomized trials (4723 participants). Pooled estimates showed significant reductions in both thromboembolic events (RR 0.50, 95% CI 0.36 to 0.69) and all-cause mortality (RR 0.64, 95% CI 0.46 to 0.89). This reduction in mortality remained significant after the removal of low-quality studies (RR 0.65, 95% CI 0.46 to 0.90). Trials of self-management alone showed significant reductions in thromboembolic events (RR 0.47, 95% CI 0.31 to 0.70) and all-cause mortality (RR 0.55, 95% CI 0.36 to 0.84); self-monitoring did not (thrombotic events RR 0.57, 95% CI 0.32 to 1.00; mortality RR 0.84, 95% CI 0.50 to 1.41). Self-monitoring significantly reduced major haemorrhages (RR 0.56, 95% CI 0.35 to 0.91) whilst self-management did not (RR 1.12, 95% CI 0.78 to 1.61). Twelve trials reported improvements in the percentage of mean INR measurements in the therapeutic range. No heterogeneity was identified in any of these comparisons.

AUTHORS' CONCLUSIONS

Compared to standard monitoring, patients who self-monitor or self-manage can improve the quality of their oral anticoagulation therapy. The number of thromboembolic events and mortality were decreased without increases in harms. However, self-monitoring or self-management were not feasible for up to half of the patients requiring anticoagulant therapy. Reasons included patient refusal, exclusion by their general practitioner, and inability to complete training.