Self-monitoring of oral anticoagulation: does it work outside trial conditions?

Self-Monitoring Kidney Function Post Transplantation: Reliability of Patient-Reported Data

Background

The high frequency of outpatient visits after kidney transplantation is burdensome to both the recovering patient and health care capacity. Self-monitoring kidney function offers a promising strategy to reduce the number of these outpatient visits.

Objective

The objective of this study was to investigate whether it is safe to rely on patients’ self-measurements of creatinine and blood pressure, using data from a self-management randomized controlled trial.

Methods

For self-monitoring creatinine, each participant received a StatSensor Xpress-i Creatinine Meter and related test material. For self-monitoring blood pressure, each participant received a Microlife WatchBP Home, an oscillometric device for blood pressure self-measurement on the upper arm. Both devices had a memory function and the option to download stored values to a computer. During the first year post transplantation, 54 patients registered their self-measured creatinine values in a Web-based Self-Management Support System (SMSS) which provided automatic feedback on the registered values (eg, seek contact with hospital). Values registered in the SMSS were compared with those logged automatically in the creatinine device to study reliability of registered data. Adherence to measurement frequency was determined by comparing the number of requested with the number of performed measurements. To study adherence to provided feedback, SMSS-logged feedback and information from the electronic hospital files were analyzed.

Results

Level of adherence was highest during months 2-4 post transplantation with over 90% (42/47) of patients performing at least 75% of the requested measurements. Overall, 87.00% (3448/3963) of all registered creatinine values were entered correctly, although values were often registered several days later. If (the number of) measured and registered values deviated, the mean of registered creatinine values was significantly lower than what was measured, suggesting active selection of lower creatinine values. Adherence to SMSS feedback ranged from 53% (14/24) to 85% (33/39), depending on the specific feedback.

Conclusions

Patients’ tendency to postpone registration and to select lower creatinine values for registration and the suboptimal adherence to the feedback provided by the SMSS might challenge safety. This should be well considered when designing self-monitoring care systems, for example by ensuring that self-measured data are transferred automatically to an SMSS.

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.

Application of a point of care creatinine device for trend monitoring in kidney transplant patients: fit for purpose?

BACKGROUND

The StatSensor® Xpress-i™, a point-of-care system for blood creatinine measurement, offers patients the possibility of self-monitoring creatinine. In this study, the analytical performance of the StatSensor® for both detecting current renal function and monitoring renal (dys)function in kidney transplant patients was examined.

METHODS

Accuracy of the StatSensor® with capillary and venous whole blood was evaluated and compared to an isotopic dilution mass spectrometry (IDMS)-traceable enzymatic creatinine test in venous serum (n=138). Twenty Li-heparin samples were compared to the IDMS reference method performed by a Joint Committee for Traceability in Laboratory Medicine (JCTLM)-listed reference laboratory (RfB, Bonn, Germany). To evaluate StatSensor®'s suitability to monitor kidney function, both venous and capillary samples were obtained in 20 hospitalized transplantation patients. Venous samples were analyzed with an IDMS-traceable enzymatic test, capillary samples were measured using the StatSensor®. For all 2-day intervals, percentage change in creatinine was compared between both methods.

RESULTS

The StatSensor® did not meet total allowable error criterion of 6.9%. Average overall CVa for the StatSensor® was 10.4% and 5.2% for capillary and venous whole blood results, respectively. Overall CVa for the central laboratory serum creatinine method was <1.5%. For monitoring renal (dys)function, total agreement of the StatSensor® with an IDMS-traceable enzymatic test was 68% using a 10% Δ change. No significant differences were found between the changes observed by both methods.

CONCLUSIONS

Capillary blood testing with the StatSensor® is not advisable for determining current renal function with a single creatinine measurement in kidney transplant patients, mainly due to excessive analytical imprecision. However, our results suggest that capillary blood testing with the StatSensor® can be used for daily trend monitoring of kidney function after renal transplantation.

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.

Supporting patients to self-monitor their oral anticoagulation therapy: recommendations based on a qualitative study of patients' experiences

BACKGROUND

Clinical trials suggest that oral anticoagulation therapy (OAT) self-monitoring is safe and effective, however little is known about the patient experience of this process. There is a lack of understanding about how best to train and support patients embarking on OAT self-monitoring.

AIM

To collect in-depth information about patients' experiences of OAT self-monitoring outside of clinical trial conditions and to produce a set of recommendations on how best to support such patients.

DESIGN AND SETTING

Semi-structured qualitative interviews with patients who self-monitor and live in England.

METHOD

In total, 26 of the 267 (9.7%) who participated in the Cohort study of Anticoagulation Self-Monitoring (CASM) and were still self-monitoring after 12 months' follow-up were interviewed. Topics discussed included experiences of OAT self-monitoring, healthcare support, training, and decision making. Framework analysis was used.

RESULTS

Following initial problems using the monitoring device, interviewees described a mostly positive experience. Although less effort was expended attending monitoring appointments with health professionals, effort was required to conduct self-monitoring tests and to interpret and act on the results. Desire to self-manage was variable, especially when dosing advice systems worked promptly and reliably. Interviewees overcame patchy healthcare system knowledge and support of self-monitoring by educating themselves. Family and friends provided support with learning to use the monitor and managing OAT dosage adjustments.

CONCLUSION

Better, more-consistent training and health-service support would have alleviated a number of problems encountered by these patients who were self-monitoring. This training and support will become even more important if self-monitoring becomes more accessible to the general population of people on OAT.

Sex differences in treatment quality of self-managed oral anticoagulant therapy: 6,900 patient-years of follow-up

Background

Patient-self-management (PSM) of oral anticoagulant therapy with vitamin K antagonists has demonstrated efficacy in randomized, controlled trials. However, the effectiveness and efficacy of PSM in clinical practice and whether outcomes are different for females and males has been sparsely investigated.The objective is to evaluate the sex-dependent effectiveness of PSM of oral anticoagulant therapy in everyday clinical practice.

Methods

All patients performing PSM affiliated to Aarhus University Hospital and Aalborg University Hospital, Denmark in the period 1996–2012 were included in a case-series study. The effectiveness was estimated using the following parameters: stroke, systemic embolism, major bleeding, intracranial bleeding, gastrointestinal bleeding, death and time spent in the therapeutic international normalized ratio (INR) target range. Prospectively registered patient data were obtained from two databases in the two hospitals. Cross-linkage between the databases and national registries provided detailed information on the incidence of death, bleeding and thromboembolism on an individual level.

Results

A total of 2068 patients were included, representing 6,900 patient-years in total. Males achieved a significantly better therapeutic INR control than females; females spent 71.1% of the time within therapeutic INR target range, whereas males spent 76.4% (p<0.0001). Importantly, death, bleeding and thromboembolism were not significantly different between females and males.

Conclusions

Among patients treated with self-managed oral anticoagulant therapy, males achieve a higher effectiveness than females in terms of time spent in therapeutic INR range, but the incidence of major complications is low and similar in both sexes.

Attitudes and preferences on the use of mobile health technology and health games for self-management: interviews with older adults on anticoagulation therapy

Background

Older adults are at substantial risk for cardiovascular disorders that may require anticoagulation therapy. Those on warfarin therapy report dissatisfaction and reduced quality of life (QOL) resulting from the treatment. Advances in the area of mobile health (mHealth) technology have resulted in the design and development of new patient-centric models for the provision of personalized health care services to improve care delivery. However, there is a paucity of research examining the effectiveness of mHealth tools on knowledge, attitudes, and patient satisfaction with treatment, as well as self-management, adherence to therapy, and QOL in older adults with chronic illness conditions requiring long-term warfarin therapy.

Objective

The objective of the study was to explore the attitudes and preferences of older adults on warfarin therapy regarding the use of mHealth technology and health games to gain skills for self-management.

Methods

We conducted group and individual interviews with patients (60 years or older) on warfarin therapy at two anticoagulation clinics affiliated with an academic medical center. We held 4 group and 2 individual interviews, resulting in 11 patient participants and 2 family caregiver participants. We used structured questions on three topic areas including medication self-management strategies, mHealth technology use, and health games for exercise. We demonstrated some commercial health apps related to medication management, vitamin K content of food, and a videogame for balance exercise. Discussions were audiotaped and transcribed verbatim. Common themes were drawn using content analysis.

Results

The participants reported awareness of the importance of staying on schedule with warfarin therapy. They also acknowledged that negative experiences of friends or family members who were taking warfarin influenced their desire to keep on schedule with warfarin therapy. In addition, the participants expressed that the use of mHealth technology may be helpful for medication management. They also expressed the need for family support in the use of health technology devices. Moreover, the participants discussed concerns and challenges to use health technology and health games, and provided suggestions on ways to make mHealth technology and health games elder-friendly.

Conclusions

These findings indicate that our older adults on warfarin therapy are interested in mHealth technology specific to warfarin medication management and health games. Further research needs to be done to validate these findings. Elder-friendly designs, technology support, and physical safety using mHealth technology may be useful in this population. These findings can be used to inform a larger study to design and test an elder-centered mHealth technology in this target population.

Cost-effectiveness of pharmacogenetics in anticoagulation: international differences in healthcare systems and costs

Genotyping patients for CYP2C9 and VKORC1 polymorphisms can improve the accuracy of dosing during the initiation of anticoagulation with vitamin K antagonists (coumarin derivatives). The anticipated degree of improvement in the safety of anticoagulation with coumarins through genotyping may vary depending on the quality of patient care, which varies both with and among countries. The management and the cost of anticoagulant care can therefore influence the cost-effectiveness of genotyping within any given country. In this article, we provide an overview of the cost-effectiveness of pharmacogenetics-guided dosing of coumarin derivatives. We describe the organization of anticoagulant care in the UK, Sweden, The Netherlands, Greece, Germany and Austria, where a genotype-guided dosing algorithm is currently being investigated as part of the EU-PACT trial. We also explore the costs of anticoagulant care for the treatment of atrial fibrillation in these countries.

Factors determining patients' intentions to use point-of-care testing medical devices for self-monitoring: the case of international normalized ratio self-testing

PURPOSE

To identify factors that determine patients' intentions to use point-of-care medical devices, ie, portable coagulometer devices for self-testing of the international normalized ratio (INR) required for ongoing monitoring of blood-coagulation intensity among patients on long-term oral anticoagulation therapy with vitamin K antagonists, eg, warfarin.

METHODS

A cross-sectional study that applied the technology-acceptance model through a self-completed questionnaire, which was administered to a convenience sample of 125 outpatients attending outpatient anticoagulation services at a district general hospital in London, UK. Data were analyzed using descriptive statistics, factor analyses, and structural equation modeling.

RESULTS

The participants were mainly male (64%) and aged ≥ 71 years (60%). All these patients were attending the hospital outpatient anticoagulation clinic for INR testing; only two patients were currently using INR self-testing, 84% of patients had no knowledge about INR self-testing using a portable coagulometer device, and 96% of patients were never offered the option of the INR self-testing. A significant structural equation model explaining 79% of the variance in patients' intentions to use INR self-testing was observed. The significant predictors that directly affected patients' intention to use INR self-testing were the perception of technology (β = 0.92, P < 0.001), trust in doctor (β = -0.24, P = 0.028), and affordability (β = 0.15, P = 0.016). In addition, the perception of technology was significantly affected by trust in doctor (β = 0.43, P = 0.002), age (β = -0.32, P < 0.001), and affordability (β = 0.23, P = 0.013); thereby, the intention to use INR self-testing was indirectly affected by trust in doctor (β = 0.40), age (β = -0.29), and affordability (β = 0.21) via the perception of technology.

CONCLUSION

Patients' intentions to use portable coagulometers for INR self-testing are affected by patients' perceptions about the INR testing device, the cost of device, trust in doctors/clinicians, and the age of the patient, which need to be considered prior to any intervention involving INR self-testing by patients. Manufacturers should focus on increasing the affordability of INR testing devices for patients' self-testing and on the potential role of medical practitioners in supporting use of these medical devices as patients move from hospital to home testing.

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.

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.

Point-of-care testing in haemostasis

Point-of-care testing (POCT) in haematology has seen a significant increase in both the spectrum of tests available and the number of tests performed annually. POCT is frequently undertaken with the belief that this will reduce the turnaround time for results and so improve patient care. The most obvious example of POCT in haemostasis is the out-of-hospital monitoring of the International Normalized Ratio in patients receiving a vitamin K antagonist, such as warfarin. Other areas include the use of the Activated Clotting Time to monitor anticoagulation for patients on cardio-pulmonary bypass, platelet function testing to identify patients with apparent aspirin or clopidogrel resistance and thrombelastography to guide blood product replacement during cardiac and hepatic surgery. In contrast to laboratory testing, POCT is frequently undertaken by untrained or semi-trained individuals and in many cases is not subject to the same strict quality control programmes that exist in the central laboratory. Although external quality assessment programmes do exist for some POCT assays these are still relatively few. The use of POCT in haematology, particularly in the field of haemostasis, is likely to expand and it is important that systems are in place to ensure that the generated results are accurate and precise.

Characteristics of ambulatory anticoagulant adverse drug events: a descriptive study

BACKGROUND

Despite the high frequency with which adverse drug events (ADEs) occur in outpatient settings, detailed information regarding these events remains limited. Anticoagulant drugs are associated with increased safety concerns and are commonly involved in outpatient ADEs. We therefore sought to evaluate ambulatory anticoagulation ADEs and the patient population in which they occurred within the Duke University Health System (Durham, NC, USA).

METHODS

A retrospective chart review of ambulatory warfarin-related ADEs was conducted. An automated trigger surveillance system identified eligible events in ambulatory patients admitted with an International Normalized Ratio (INR) >3 and administration of vitamin K. Event and patient characteristics were evaluated, and quality/process improvement strategies for ambulatory anticoagulation management are described.

RESULTS

A total of 169 events in 167 patients were identified from December 1, 2006-June 30, 2008 and included in the study. A median supratherapeutic INR of 6.1 was noted, and roughly half of all events (52.1%) were associated with a bleed. Nearly 74% of events resulted in a need for fresh frozen plasma; 64.8% of bleeds were classified as major. A total of 59.2% of events were at least partially responsible for hospital admission. Median patient age was 68 y (range 36-95 y) with 24.9% initiating therapy within 3 months prior to the event. Of events with a prior documented patient visit (n = 157), 73.2% were seen at a Duke clinic or hospital within the previous month. Almost 80% of these patients had anticoagulation therapy addressed, but only 60.0% had a follow-up plan documented in the electronic note.

CONCLUSIONS

Ambulatory warfarin-related ADEs have significant patient and healthcare utilization consequences in the form of bleeding events and associated hospital admissions. Recommendations for improvement in anticoagulation management include use of information technology to assist monitoring and follow-up documentation, avoid drug interactions, and engage patients in their care.