Self management of oral anticoagulation: randomised trial

Does self-management of oral anticoagulation therapy improve quality of life and anxiety?

BACKGROUND

Research related to service requirements for anticoagulation management has focussed on clinical and health economic outcomes and paid little attention to the impact of treatment and service delivery on patients' quality of life. This was the first large UK study to evaluate the effect of patient self-management (PSM) of oral anticoagulation on treatment-related quality of life (TRQoL) and anxiety in comparison with routine care (RC) and to explore the effect of level of therapeutic control on TRQoL and anxiety across and within each model of care.

METHODS

A quantitative survey, set in primary care in the West Midlands. The subjects were 517 randomized controlled trial participants, 242 receiving PSM and 275 RC. Postal questionnaires at baseline and 12 months comprised the State Trait Anxiety Inventory and a treatment-specific measure of positive (satisfaction and self-efficacy) and negative aspects (daily hassles, strained social network and psychological distress) of TRQoL. Change in anxiety and TRQoL scores were compared between PSM and RC. Subgroup analysis was based upon level of therapeutic control (high, medium and low).

RESULTS

Overall, 83% (n = 202) PSM and 55% (n = 161) RC patients contributed data. Anxiety scores were similar in both groups. PSM demonstrated greater improvement in self-efficacy than RC across the study period. A statistically significant between-group difference (PSM versus RC) in the self-efficacy also existed in subgroups with medium and high levels of therapeutic control.

CONCLUSIONS

PSM is not associated with increased anxiety and has a positive effect upon some aspects of TRQoL compared to RC.

Thromboembolism

INTRODUCTION

Deep venous thrombosis (DVT) or pulmonary embolism may occur in almost 2 in 1000 people each year, with up to 25% of those having a recurrence. Around 5% to 15% of people with untreated DVT may die from pulmonary embolism. Risk factors for DVT include immobility, surgery (particularly orthopaedic), malignancy, pregnancy, older age, and inherited or acquired prothrombotic clotting disorders.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of treatments for proximal DVT? What are the effects of treatments for isolated calf DVT? What are the effects of treatments for pulmonary embolism? What are the effects of interventions on oral anticoagulation management in people with thromboembolism? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2010 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 45 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: anticoagulation; compression stockings; low molecular weight heparin (short and long term, once or twice daily, and home treatment); oral anticoagulants (short and long term, high intensity, abrupt discontinuation, and computerised decision support); prolonged duration of anticoagulation; thrombolysis; vena cava filters; and warfarin.

Hypothetical versus real preferences: results from an opportunistic field experiment

Over recent years there has been renewed interest in cost-benefit analysis (CBA) in health care but the 'hypothetical bias' concern (i.e. the belief that WTP values overstate real preferences) is a remaining anxiety. This paper reports new empirical data comparing hypothetical and real preferences in a health care context, using the clinical setting of patient self-management (PSM) of anticoagulation (warfarin) therapy. The data offer considerable support for the use of WTP and CBAs in a self-management health care context; the hypothetical bias hypothesis is not supported by our data. The generalisability of these results to other health care settings needs to be explored.

Telemonitoring and self-management in the control of hypertension (TASMINH2): a randomised controlled trial

BACKGROUND

Control of blood pressure is a key component of cardiovascular disease prevention, but is difficult to achieve and until recently has been the sole preserve of health professionals. This study assessed whether self-management by people with poorly controlled hypertension resulted in better blood pressure control compared with usual care.

METHODS

This randomised controlled trial was undertaken in 24 general practices in the UK. Patients aged 35-85 years were eligible for enrolment if they had blood pressure more than 140/90 mm Hg despite antihypertensive treatment and were willing to self-manage their hypertension. Participants were randomly assigned in a 1:1 ratio to self-management, consisting of self-monitoring of blood pressure and self-titration of antihypertensive drugs, combined with telemonitoring of home blood pressure measurements or to usual care. Randomisation was done by use of a central web-based system and was stratified by general practice with minimisation for sex, baseline systolic blood pressure, and presence or absence of diabetes or chronic kidney disease. Neither participants nor investigators were masked to group assignment. The primary endpoint was change in mean systolic blood pressure between baseline and each follow-up point (6 months and 12 months). All randomised patients who attended follow-up visits at 6 months and 12 months and had complete data for the primary outcome were included in the analysis, without imputation for missing data. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN17585681.

FINDINGS

527 participants were randomly assigned to self-management (n=263) or control (n=264), of whom 480 (91%; self-management, n=234; control, n=246) were included in the primary analysis. Mean systolic blood pressure decreased by 12.9 mm Hg (95% CI 10.4-15.5) from baseline to 6 months in the self-management group and by 9.2 mm Hg (6.7-11.8) in the control group (difference between groups 3.7 mm Hg, 0.8-6.6; p=0.013). From baseline to 12 months, systolic blood pressure decreased by 17.6 mm Hg (14.9-20.3) in the self-management group and by 12.2 mm Hg (9.5-14.9) in the control group (difference between groups 5.4 mm Hg, 2.4-8.5; p=0.0004). Frequency of most side-effects did not differ between groups, apart from leg swelling (self-management, 74 patients [32%]; control, 55 patients [22%]; p=0.022).

INTERPRETATION

Self-management of hypertension in combination with telemonitoring of blood pressure measurements represents an important new addition to control of hypertension in primary care.

FUNDING

Department of Health Policy Research Programme, National Coordinating Centre for Research Capacity Development, and Midlands Research Practices Consortium.

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.

Current issues in patient adherence and persistence: focus on anticoagulants for the treatment and prevention of thromboembolism

Warfarin therapy reduces morbidity and mortality related to thromboembolism. Yet adherence to long-term warfarin therapy remains challenging due to the risks of anticoagulant-associated complications and the burden of monitoring. The aim of this paper is to review determinants of adherence and persistence on long-term anticoagulant therapy for atrial fibrillation and venous thromboembolism. We evaluate what the current literature reveals about the impact of warfarin on quality of life, examine warfarin trial data for patterns of adherence, and summarize known risk factors for warfarin discontinuation. Studies suggest only modest adverse effects of warfarin on quality of life, but highlight the variability of individual lifestyle experiences of patients on warfarin. Interestingly, clinical trials comparing anticoagulant adherence to alternatives (such as aspirin) show that discontinuation rates on warfarin are not consistently higher than in control arms. Observational studies link a number of risk factors to warfarin non-adherence including younger age, male sex, lower stroke risk, poor cognitive function, poverty, and higher educational attainment. In addition to differentiating the relative impact of warfarin-associated complications (such as bleeding) versus the lifestyle burdens of warfarin monitoring on adherence, future investigation should focus on optimizing patient education and enhancing models of physician-patient shared-decision making around anticoagulation.

Primary care practices and determinants of optimal anticoagulation management in a collaborative care model

BACKGROUND

In a collaborative care model (CCM) for managing oral anticoagulant therapy, patients are followed at a pharmacist-managed anticoagulation service and, once stabilized, are transferred to their primary care physician. The objective of this study was to describe physicians' clinical practices and the practice characteristics associated with better international normalized ratio (INR) control in a CCM.

METHODS

A telephone questionnaire about their practices was administered to 121 physicians exposed to a CCM. The physicians followed 121 patients for a mean of 14.5 weeks. The percentage of time within the exact INR target range was computed and dichotomized (> or = or < median time within target range). Determinants of better INR control were identified using logistic regression models.

RESULTS

The survey revealed that, after discharge from the pharmacist-managed anticoagulation service, patients are followed mainly by physicians and their secretaries. Physicians do not often consult other health professionals. Few report using technological resources to obtain INR results (39.7%), document medical follow-up (6.6%), or detect drug (32.2%) and food (9.9%) interactions. The median percentage of time within the exact INR target range was 84%. Determinants of better INR control include using computerized support to monitor patients (odds ratio [OR] 9.16, 95% CI 1.77-47.4) and detect drug interactions (OR 3.49, 95% CI 1.71-7.10) and consulting specialists (OR 5.92, 95% CI 1.49-32.48).

CONCLUSIONS

Primary care physicians are poorly supported by technological and human resources to monitor patients on oral anticoagulant. Even in a CCM, interprofessional collaboration and better technological support may be associated with optimal INR control.

Patient participation: current knowledge and applicability to patient safety

Patient participation is increasingly recognized as a key component in the redesign of health care processes and is advocated as a means to improve patient safety. The concept has been successfully applied to various areas of patient care, such as decision making and the management of chronic diseases. We review the origins of patient participation, discuss the published evidence on its efficacy, and summarize the factors influencing its implementation. Patient-related factors, such as acceptance of the new patient role, lack of medical knowledge, lack of confidence, comorbidity, and various sociodemographic parameters, all affect willingness to participate in the health care process. Among health care workers, the acceptance and promotion of patient participation are influenced by other issues, including the desire to maintain control, lack of time, personal beliefs, type of illness, and training in patient-caregiver relationships. Social status, specialty, ethnic origin, and the stakes involved also influence patient and health care worker acceptance. The London Declaration, endorsed by the World Health Organization World Alliance for Patient Safety, calls for a greater role for patients to improve the safety of health care worldwide. Patient participation in hand hygiene promotion among staff to prevent health care-associated infection is discussed as an illustrative example. A conceptual model including key factors that influence participation and invite patients to contribute to error prevention is proposed. Further research is essential to establish key determinants for the success of patient participation in reducing medical errors and in improving patient safety.

Use of error grid analysis to evaluate acceptability of a point of care prothrombin time meter

BACKGROUND

Statistical methods (linear regression, correlation analysis, etc.) are frequently employed in comparing methods in the central laboratory (CL). Assessing acceptability of point of care testing (POCT) equipment, however, is more difficult because statistically significant biases may not have an impact on clinical care. We showed how error grid (EG) analysis can be used to evaluate POCT PT INR with the CL.

MATERIALS AND METHODS

We compared results from 103 patients seen in an anti-coagulation clinic that were on Coumadin maintenance therapy using fingerstick samples for POCT (Roche CoaguChek XS and S) and citrated venous blood samples for CL (Stago STAR). To compare clinical acceptability of results we developed an EG with zones A, B, C and D.

RESULTS

Using 2nd order polynomial equation analysis, POCT results highly correlate with the CL for CoaguChek XS (R(2)=0. 955) and CoaguChek S (R(2)=0. 93), respectively but does not indicate if POCT results are clinically interchangeable with the CL. Using EG it is readily apparent which levels can be considered clinically identical to the CL despite analytical bias.

CONCLUSION

We have demonstrated the usefulness of EG in determining acceptability of POCT PT INR testing and how it can be used to determine cut-offs where differences in POCT results may impact clinical care.

Point-of-Care International Normalized Ratio (INR) Monitoring Devices for Patients on Long-term Oral Anticoagulation Therapy: An Evidence-Based Analysis

SUBJECT OF THE EVIDENCE-BASED ANALYSIS: The purpose of this evidence based analysis report is to examine the safety and effectiveness of point-of-care (POC) international normalized ratio (INR) monitoring devices for patients on long-term oral anticoagulation therapy (OAT).

CLINICAL NEED

TARGET POPULATION AND CONDITION Long-term OAT is typically required by patients with mechanical heart valves, chronic atrial fibrillation, venous thromboembolism, myocardial infarction, stroke, and/or peripheral arterial occlusion. It is estimated that approximately 1% of the population receives anticoagulation treatment and, by applying this value to Ontario, there are an estimated 132,000 patients on OAT in the province, a figure that is expected to increase with the aging population. Patients on OAT are regularly monitored and their medications adjusted to ensure that their INR scores remain in the therapeutic range. This can be challenging due to the narrow therapeutic window of warfarin and variation in individual responses. Optimal INR scores depend on the underlying indication for treatment and patient level characteristics, but for most patients the therapeutic range is an INR score of between 2.0 and 3.0. The current standard of care in Ontario for patients on long-term OAT is laboratory-based INR determination with management carried out by primary care physicians or anticoagulation clinics (ACCs). Patients also regularly visit a hospital or community-based facility to provide a venous blood samples (venipuncture) that are then sent to a laboratory for INR analysis. Experts, however, have commented that there may be under-utilization of OAT due to patient factors, physician factors, or regional practice variations and that sub-optimal patient management may also occur. There is currently no population-based Ontario data to permit the assessment of patient care, but recent systematic reviews have estimated that less that 50% of patients receive OAT on a routine basis and that patients are in the therapeutic range only 64% of the time.

OVERVIEW OF POC INR DEVICES

POC INR devices offer an alternative to laboratory-based testing and venipuncture, enabling INR determination from a fingerstick sample of whole blood. Independent evaluations have shown POC devices to have an acceptable level of precision. They permit INR results to be determined immediately, allowing for more rapid medication adjustments. POC devices can be used in a variety of settings including physician offices, ACCs, long-term care facilities, pharmacies, or by the patients themselves through self-testing (PST) or self-management (PSM) techniques. With PST, patients measure their INR values and then contact their physician for instructions on dose adjustment, whereas with PSM, patients adjust the medication themselves based on pre-set algorithms. These models are not suitable for all patients and require the identification and education of suitable candidates. Potential advantages of POC devices include improved convenience to patients, better treatment compliance and satisfaction, more frequent monitoring and fewer thromboembolic and hemorrhagic complications. Potential disadvantages of the device include the tendency to underestimate high INR values and overestimate low INR values, low thromboplastin sensitivity, inability to calculate a mean normal PT, and errors in INR determination in patients with antiphospholipid antibodies with certain instruments. Although treatment satisfaction and quality of life (QoL) may improve with POC INR monitoring, some patients may experience increased anxiety or preoccupation with their disease with these strategies.

RESEARCH QUESTIONS

1. EffectivenessDoes POC INR monitoring improve clinical outcomes in various settings compared to standard laboratory-based testing?Does POC INR monitoring impact patient satisfaction, QoL, compliance, acceptability, convenience compared to standard laboratory-based INR determination?Settings include primary care settings with use of POC INR devices by general practitioners or nurses, ACCs, pharmacies, long-term care homes, and use by the patient either for PST or PSM. 2. Cost-effectivenessWhat is the cost-effectiveness of POC INR monitoring devices in various settings compared to standard laboratory-based INR determination?

INCLUSION CRITERIA

English-language RCTs, systematic reviews, and meta-analysesPUBLICATION DATES: 1996 to November 25, 2008POPULATION: patients on OATINTERVENTION: anticoagulation monitoring by POC INR device in any setting including anticoagulation clinic, primary care (general practitioner or nurse), pharmacy, long-term care facility, PST, PSM or any other POC INR strategyMINIMUM SAMPLE SIZE: 50 patients Minimum follow-up period: 3 monthsCOMPARATOR: usual care defined as venipuncture blood draw for an INR laboratory test and management provided by an ACC or individual practitioner

OUTCOMES

Hemorrhagic events, thromboembolic events, all-cause mortality, anticoagulation control as assessed by proportion of time or values in the therapeutic range, patient reported outcomes including satisfaction, QoL, compliance, acceptability, convenience

EXCLUSION CRITERIA

Non-RCTs, before-after studies, quasi-experimental studies, observational studies, case reports, case series, editorials, letters, non-systematic reviews, conference proceedings, abstracts, non-English articles, duplicate publicationsStudies where POC INR devices were compared to laboratory testing to assess test accuracyStudies where the POC INR results were not used to guide patient management

METHOD OF REVIEW

A search of electronic databases (OVID MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, The Cochrane Library, and the International Agency for Health Technology Assessment [INAHTA] database) was undertaken to identify evidence published from January 1, 1998 to November 25, 2008. Studies meeting the inclusion criteria were selected from the search results. Reference lists of selected articles were also checked for relevant studies.

SUMMARY OF FINDINGS

Five existing reviews and 22 articles describing 17 unique RCTs met the inclusion criteria. Three RCTs examined POC INR monitoring devices with PST strategies, 11 RCTs examined PSM strategies, one RCT included both PST and PSM strategies and two RCTs examined the use of POC INR monitoring devices by health care professionals.

ANTICOAGULATION CONTROL

Anticoagulation control is measured by the percentage of time INR is within the therapeutic range or by the percentage of INR values in the therapeutic range. Due to the differing methodologies and reporting structures used, it was deemed inappropriate to combine the data and estimate whether the difference between groups would be significant. Instead, the results of individual studies were weighted by the number of person-years of observation and then pooled to calculate a summary measure. Across most studies, patients in the intervention groups tended to have a higher percentage of time and values in the therapeutic target range in comparison to control patients. When the percentage of time in the therapeutic range was pooled across studies and weighted by the number of person-years of observation, the difference between the intervention and control groups was 4.2% for PSM, 7.2% for PST and 6.1% for POC use by health care practitioners. Overall, intervention patients were in the target range 69% of the time and control patients were in the therapeutic target range 64% of the time leading to an overall difference between groups of roughly 5%.

MAJOR COMPLICATIONS AND DEATHS

There was no statistically significant difference in the number of major hemorrhagic events between patients managed with POC INR monitoring devices and patients managed with standard laboratory testing (OR =0.74; 95% CI: 0.52- 1.04). This difference was non-significant for all POC strategies (PSM, PST, health care practitioner). Patients managed with POC INR monitoring devices had significantly fewer thromboembolic events than usual care patients (OR =0.52; 95% CI: 0.37 - 0.74). When divided by POC strategy, PSM resulted in significantly fewer thromboembolic events than usual care (OR =0.46.; 95% CI: 0.29 - 0.72). The observed difference in thromboembolic events for PSM remained significant when the analysis was limited to major thromboembolic events (OR =0.40; 95% CI: 0.17 - 0.93), but was non-significant when the analysis was limited to minor thromboembolic events (OR =0.73; 95% CI: 0.08 - 7.01). PST and GP/Nurse strategies did not result in significant differences in thromboembolic events, however there were only a limited number of studies examining these interventions. No statistically significant difference was observed in the number of deaths between POC intervention and usual care control groups (OR =0.67; 95% CI: 0.41 - 1.10). This difference was non-significant for all POC strategies. Only one study reported on survival with 10-year survival rate of 76.1% in the usual care control group compared to 84.5% in the PSM group (P=0.05). ES Table 1:Summary Results of Meta-Analyses of Major Complications and Deaths in POC INR Monitoring StudiesEventNo. of trials(patients)OR(M-H, Random Effects)95% CIMajor Haemorrhages16 (5057)0.740.52 to 1.04Thromboembolic events16 (5057)0.520.37 to 0.74Deaths11 (2906)0.670.41 to 1.10 PATIENT SATISFACTION AND QUALITY OF LIFE: Quality of life measures were reported in eight studies comparing POC INR monitoring to standard laboratory testing using a variety of measurement tools. It was thus not possible to calculate a quantitative summary measure. The majority of studies reported favourable impacts of POC INR monitoring on QoL and found better treatment satisfaction with POC monitoring. Results from a pre-analysis patient and caregiver focus group conducted in Ontario also indicated improved patient QoL with POC monitoring. (ABSTRACT TRUNCATED)

Effect of an interactive voice response system on oral anticoagulant management

BACKGROUND

Monitoring oral anticoagulants is logistically challenging for both patients and medical staff. We evaluated the effect of adding an interactive voice response system to computerized decision support for oral anticoagulant management.

METHODS

We developed an interactive voice response system to communicate to patients the results of international normalized ratio testing and their dosage schedules for anticoagulation therapy. The system also reminded patients of upcoming and missed appointments for blood tests. We recruited patients whose anticoagulation control was stable after at least 3 months of warfarin therapy. We prospectively examined clinical data and outcomes for these patients for an intervention period of at least 3 months. We also collected retrospective data for each patient for the 3 months before study enrolment.

RESULTS

We recruited 226 patients between Nov. 23, 2006, and Aug. 1, 2007. The mean duration of the intervention period (prospective data collection) was 4.2 months. Anticoagulation control was similar for the periods during and preceding the intervention (mean time within the therapeutic range 80.3%, 95% confidence interval [CI] 77.5% to 83.1% v. 79.9%, 95% CI 77.3% to 82.6%). The interactive voice response system delivered 1211 (77.8%) of 1557 scheduled dosage messages, with no further input required from clinic staff. The most common reason for clinic staff having to deliver the remaining messages (accounting for 143 [9.2%] of all messages) was an international normalized ratio that was excessively high or low, (i.e., 0.5 or more outside the therapeutic range). When given the option, 76.6% of patients (164/214) chose to continue with the interactive voice response system for management of their anticoagulation after the study was completed. The system reduced staff workload for monitoring anticoagulation therapy by 48 min/wk, a 33% reduction from the baseline of 2.4 hours.

INTERPRETATION

Interactive voice response systems have a potential role in improving the monitoring of patients taking oral anticoagulants. Further work is required to determine the generalizability and cost-effectiveness of these results.

Potentially avoidable inpatient nights among warfarin receiving patients; an audit of a single university teaching hospital

BACKGROUND

Warfarin is an oral anticoagulant (OAT) that needs active management to ensure therapeutic range. Initial management is often carried out as an inpatient, though not requiring inpatient facilities. This mismatch results in financial costs which could be directed more efficaciously. The extent of this has previously been unknown. Here we aim to calculate the potential number of bed nights which may be saved among those being dose optimized as inpatients and examine associated factors.

METHODS

A 6 week prospective audit of inpatients receiving OAT, at Cork University Hospital, was carried out. The study period was from 11th June 2007 to 20th July 2007. Data was collected from patient's medications prescription charts, medical record files, and computerised haematology laboratory records. The indications for OAT, the patient laboratory coagulation results and therapeutic intervals along with patient demographics were analysed. The level of potentially avoidable inpatient nights in those receiving OAT in hospital was calculated and the potential cost savings quantified. Potential avoidable bed nights were defined as patients remaining in hospital for the purpose of optimizing OAT dosage, while receiving subtherapeutic or therapeutic OAT (being titred up to therapeutic levels) and co-administered covering low molecular weight heparin, and requiring no other active care. The average cost of euro638 was taken as the per night hospital stay cost for a non-Intensive Care bed. Ethical approval was granted from the Ethical Committee of the Cork Teaching Hospitals, Cork, Ireland.

RESULTS

A total of 158 patients were included in the audit. There was 94 men (59.4%) and 64 women (40.6%). The mean age was 67.8 years, with a median age of 70 years.Atrial Fibrillation (43%, n = 70), followed by aortic valve replacement (15%, n = 23) and pulmonary emboli (11%, n = 18) were the commonest reasons for prescribing OAT. 54% had previously been prescribed OAT prior to current admission.It was confirmed that, there are potentially avoidable nights in patients receiving OAT. The majority of this group were those being commenced on OAT for the first time (p = 0.00002), in the specialities of Cardiology, Cardiothoracic surgery and Care of the Elderly. The potential number of bed nights to be saved is 13 per week for the hospital or 1.1 bed nights per 10,000 general hospital admissions. These were predominantly weekday nights. The estimated cost of avoidable inpatient OAT dose optimization was approximately euro8300 per week.

CONCLUSION

With rising costs and the increasing demands for acute hospital beds, alterations to inpatient management for this group of patients should be considered. Alternatives include increasing the size of current anticoagulation clinics, introduction of POCT (point of care testing) devices and increased GP management. POCT can be justified based upon the publication by Gardiner et al, who showed that 87% of patients find self testing straightforward, 87% were confident in the result they obtained using the devices and 77% preferred self testing.

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

BACKGROUND

Patient self-monitoring (PSM) of oral anticoagulation therapy (OAT) can improve anticoagulant control, but poor uptake and high dropout rates have prompted suggestions that PSM is suitable for only a minority of patients in the UK.

AIMS

To determine whether PSM could be a viable alternative to regular hospital anticoagulant clinic attendance, if offered from the start of treatment.

METHODS

318 consecutive patients referred, for the first time, to an anticoagulation clinic were assessed for eligibility using established criteria. Patients electing for PSM attended training and, following successful assessment, performed a capillary blood INR every two weeks or more frequently if directed to do so by the anticoagulation clinic. Primary outcome measures were uptake of PSM and the percentage time in target therapeutic INR range (TIR) compared to patients electing for routine clinic care.

RESULTS

Of 318 patients referred for OAT, 188 were eligible for PSM. 84 (26%) elected to self-monitor, of whom 72 (23%) remained self-monitoring or had completed their course of treatment at the end of the audit. Self-monitoring patients had significantly better anticoagulant control than those receiving routine hospital anticoagulation clinic care (TIR 71% vs 60%, p = 0.003) and significantly less time outside critical limits, ie, INR <1.5 or >5.0 (0.45% vs 2.04%, p = 0.008).

CONCLUSIONS

Patients offered PSM from the start of treatment show increased uptake compared to previous UK studies and a level of oral anticoagulation control comparable to that reported in previous clinical trials.

Warfarin for atrial fibrillation in community-based practise

BACKGROUND

Previous studies of anticoagulation for atrial fibrillation (AF) have predominantly occurred in academic settings or randomized trials, limiting their generalizability.

OBJECTIVE

To describe the management of patients with AF anticoagulated with warfarin in community-based practise.

METHODS

We enrolled 3396 patients from 101 community-based practises in 38 states. Data included demographics, comorbidities, and International Normalized Ratio (INR) values. Outcomes included time in therapeutic INR range (TTR), stroke, and major hemorrhage.

RESULTS

The mean TTR was 66.5%, but varied widely among patients: 37% had TTR above 75%, while 34% had TTR below 60%. The yearly rates of major hemorrhage and stroke were 1.90 per 100 person-years and 1.00 per 100 person-years. Four percent of patients (n = 127) were intentionally targeted to a lower INR, and spent 42.7% of time with an INR below 2.0, compared to 18.8% for patients with a 2.0-3.0 range (P < 0.001). Mean TTR for new warfarin users (57.5%) remained below that of prevalent users through the first six months. Patients with interruptions of warfarin therapy had lower TTR than all others (61.6% vs. 67.2%, P < 0.001), which corrected after deleting low peri-procedural INR values (67.0% vs. 67.4%, P = 0.73).

CONCLUSIONS

Anticoagulation control varies widely among patients taking warfarin for AF. TTR is affected by new warfarin use, procedural interruptions, and INR target range. In this community-based cohort of predominantly prevalent warfarin users, rates of hemorrhage and stroke were low. The risk versus benefit of a lower INR target range to offset bleeding risk remains uncertain.

Pharmacology and management of the vitamin K antagonists: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)

This article concerning the pharmacokinetics and pharmacodynamics of vitamin K antagonists (VKAs) is part of the American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). It describes the antithrombotic effect of the VKAs, the monitoring of anticoagulation intensity, and the clinical applications of VKA therapy and provides specific management recommendations. Grade 1 recommendations are strong and indicate that the benefits do or do not outweigh the risks, burdens, and costs. Grade 2 recommendations suggest that the individual patient's values may lead to different choices. (For a full understanding of the grading, see the "Grades of Recommendation" chapter by Guyatt et al, CHEST 2008; 133:123S-131S.) Among the key recommendations in this article are the following: for dosing of VKAs, we recommend the initiation of oral anticoagulation therapy, with doses between 5 mg and 10 mg for the first 1 or 2 days for most individuals, with subsequent dosing based on the international normalized ratio (INR) response (Grade 1B); we suggest against pharmacogenetic-based dosing until randomized data indicate that it is beneficial (Grade 2C); and in elderly and other patient subgroups who are debilitated or malnourished, we recommend a starting dose of < or = 5 mg (Grade 1C). The article also includes several specific recommendations for the management of patients with nontherapeutic INRs, with INRs above the therapeutic range, and with bleeding whether the INR is therapeutic or elevated. For the use of vitamin K to reverse a mildly elevated INR, we recommend oral rather than subcutaneous administration (Grade 1A). For patients with life-threatening bleeding or intracranial hemorrhage, we recommend the use of prothrombin complex concentrates or recombinant factor VIIa to immediately reverse the INR (Grade 1C). For most patients who have a lupus inhibitor, we recommend a therapeutic target INR of 2.5 (range, 2.0 to 3.0) [Grade 1A]. We recommend that physicians who manage oral anticoagulation therapy do so in a systematic and coordinated fashion, incorporating patient education, systematic INR testing, tracking, follow-up, and good patient communication of results and dose adjustments [Grade 1B]. In patients who are suitably selected and trained, patient self-testing or patient self-management of dosing are effective alternative treatment models that result in improved quality of anticoagulation management, with greater time in the therapeutic range and fewer adverse events. Patient self-monitoring or self-management, however, is a choice made by patients and physicians that depends on many factors. We suggest that such therapeutic management be implemented where suitable (Grade 2B).

Is long-term pharmacist-managed anticoagulation service efficient? A pragmatic randomized controlled trial

BACKGROUND

Some pharmacist-managed anticoagulation services (PMAS) provide initial follow-up to patients on oral anticoagulant, who are transferred to their physician once they are stabilized. This may be as effective as and less expensive than long-term PMAS follow-up.

METHODS

Once PMAS patients were stabilized and ready for discharge, they were randomized to be transferred to their physician or stay with the PMAS. Quality of international normalized ratio (INR) control, incidence of complications, health-related quality of life, use of health care services, and direct incremental cost of PMAS follow-up were evaluated.

RESULTS

One hundred thirty-eight physicians and 250 patients participated. Patients were initially followed at the PMAS for a mean of 11.3 weeks and afterwards were followed by their physician (n = 122) or by the PMAS pharmacists (n = 128) for a mean of 14.9 and 14.5 weeks, respectively. Pharmacist-managed anticoagulation services' and physician's patients were within the exact target range 77.3% and 76.7% of the time (95% CI of the difference -4.9% to 6.0%) and within the extended range 93.0% and 91.6% of the time (95% CI -2.1% to 4.7%), respectively. Pharmacist-managed anticoagulation services patients have seen their family physician less often (95% CI -3.1 to -0.1 visit per year). Number of INR tests, incidence of complications, and health-related quality of life were similar in both groups. The incremental cost of PMAS follow-up was estimated at CAN$123.80 per patient year.

CONCLUSION

Once PMAS patients are well stabilized, maintaining a PMAS follow-up or transferring them to their physician is associated with excellent INR control. However, long-term PMAS follow-up may be more expensive.

Effect of setting, monitoring intensity and patient experience on anticoagulation control: a systematic review and meta-analysis of the literature

OBJECTIVES

To investigate the relationship between time spent in the recommended target International Normalised Ratio (INR) range and the setting and intensity of anti coagulant monitoring, in both treatment-experienced and treatment-naive atrial fibrillation (AF) patients receiving oral anticoagulation (OAC) therapy for the prevention of ischaemic stroke.

RESEARCH DESIGN AND METHODS

Systematic review of published studies on participants with atrial fibrillation on anticoagulation therapy. We compared frequent monitoring (well-controlled, according to a strict protocol) versus infrequent monitoring (frequency representative of routine clinical practice), specialised care versus usual care, and naive versus prior anticoagulant use. Meta-analysis was performed using a random effects model.

RESULTS

36 studies were included, 22 (primary data) of AF patients managed in line with the consensus guidelines target INR range of 2.0-3.0, and 14 studies (secondary data) of mixed patient groups, including AF, with an INR target of 2.0-3.5. Both data sets were combined for sensitivity analysis. Pooled mean time in INR range was 59.1% (95% CI: 55.5, 62.8%) and 64.3% (95% CI: 60.5, 68.0%) for infrequent monitoring and frequent monitoring, respectively. Significantly more time was spent in range in specialist care settings compared to usual care: +11.3% (95% CI: 0.1-21.7%). Naive OAC users spent less time in range 56.5% (95% CI: 45.5-67.5%) than existing users 61.2% (95% CI: 57.2-65.2%). All of these differences were found to be significant in the sensitivity analyses.

CONCLUSIONS

INR control is variable and dependent on monitoring intensity and duration of anticoagulant therapy.

Quality assurance for oral anticoagulation self management: a cluster randomized trial

BACKGROUND AND AIMS

External quality assessment (EQA) should be an inherent component of patient self management (PSM) of oral anticoagulation. The aim of this study was to evaluate methods of EQA for patients within a cluster randomized trial.

METHOD

After development of methods, general practises were randomly allocated to a formal EQA scheme of patients performing the test independently at home or at their practise with supervision. The supervised group of practises was further sub divided to test two other EQA methods: (i) venous sample compared with patients' point of care (POC) device; and (ii) patients POC compared with reference POC. Primary trial outcome measure was reliability of results from the formal scheme taking into account adherence and test errors.

RESULTS

Proportion of EQA scheme tests in range was 633/836 (75.7%). Proportion in range was significantly higher in group performing independently compared with supervised group, 80.1% vs. 71.5% respectively, P = 0.02. Sixty-six percent of tests were in range with venous compared with patients POC, and 88% in patients POC compared with reference POC.

CONCLUSION

Patients are able to undertake a formal EQA scheme and perform more reliably at home independently. There are satisfactory alternatives if a formal scheme is not acceptable.

Safety and effectiveness of point-of-care monitoring devices in patients on oral anticoagulant therapy: a meta-analysis

BACKGROUND

Point-of-care devices (POCDs) for monitoring long-term oral anticoagulation therapy (OAT) may be a useful alternative to laboratory-based international normalized ratio [INR] testing and clinical management.

PURPOSE

To determine clinical outcomes of the use of POCDs for OAT management by performing a meta-analysis. Previous meta-analyses on POCDs have serious limitations.

DATA SOURCES

PubMed, the Cochrane Library, DIALOG, MEDLINE, EMBASE, BIOSIS Previews and PASCAL databases.

STUDY SELECTION

Randomized controlled trials of patients on long-term OAT, comparing anticoagulation monitoring by POCD with laboratory INR testing and clinical management.

DATA EXTRACTION

1) rates of major hemorrhage; 2) rates of major thromboembolic events; 3) percentage of time that the patient is maintained within the therapeutic range; 4) deaths. Outcomes were compared using a random-effects model. Summary measures of rates were determined. The quality of studies was assessed using the Jadad scale.

DATA SYNTHESIS

Seventeen articles (16 studies) were included. Data analysis showed that POCD INR testing reduced the risk of major thromboembolic events (odds ratio [OR] = 0.51; 95% confidence interval [CI] 0.35-0.74), was associated with fewer deaths (OR = 0.58; 95% CI = 0.38-0.89), and resulted in better INR control compared with laboratory INR testing. No significant difference between the two management modalities with respect to odds ratios for major hemorrhage was found.

LIMITATIONS

Quality scores varied from 1 to 3 (out of a maximum of 5). Only 3 studies defined how thromboembolic events would be diagnosed, casting doubt on the accuracy of the reporting of thromboembolic events. The studies suggest that only 24% of patients are good candidates for self-testing and self-management. Compared with patients managed with laboratory-based monitoring, POCD patients underwent INR testing at a much higher frequency and received much more intensive education on OAT management.

CONCLUSIONS

The use of POCDs is safe and may be more effective than laboratory-based monitoring. However, most patients are not good candidates for self-testing and self-management. Patient education and frequency of testing may be the most important factors in successful PODC management. Definitive conclusions about the clinical benefits provided by self-testing and self-management require more rigorously designed trials.

Direct-to-patient expert system and home INR monitoring improves control of oral anticoagulation

BACKGROUND AND OBJECTIVE

Internet-based disease management programs have the potential to improve patient care. The objective of this study was to determine whether an interactive, internet-based system enabling supervised, patient self-management of oral anticoagulant therapy provided management comparable to an established anticoagulation clinic.

PATIENTS/METHODS

Sixty patients receiving chronic oral anticoagulant therapy who had access to the internet and a printer, were enrolled into this prospective, single-group, before-after study from a single clinic and managed between March 2002 and January 2003. Patients learned how to use a home prothrombin time monitor and how to access the system through the internet. Patients used the system for six months, with daily review by the supervising physician. The primary outcome variable was the difference in time in therapeutic range prior to and following introduction of internet-supervised patient self-management.

RESULTS

The mean time in therapeutic range increased from 63% in the anticoagulation clinic (control period) to 74.4% during internet-supervised patient self-management (study period). The mean difference score between control and study periods was 11.4% (P = 0.004, 95% confidence interval 5.5-17.3%). There were no hemorrhagic or thromboembolic complications.

CONCLUSIONS

This novel approach of internet-supervised patient self-management improved time in therapeutic range compared to an anticoagulation clinic. This is the first demonstration of an internet-based expert system enabling remote and effective management of patients on oral anticoagulants. Expert systems may be applicable for management of other chronic diseases.

Assessing differential attrition in clinical trials: self-monitoring of oral anticoagulation and type II diabetes

Background

Analyzing drop out rates and when they occur may give important information about the patient characteristics and trial characteristics that affect the overall uptake of an intervention.

Methods

We searched Medline and the Cochrane library from the beginning of the databases to May 2006 for published systematic reviews that compared the effects of self-monitoring (self-testing) or self-management (self-testing and self-dosage) of oral anticoagulation or self-monitored blood glucose in type 2 diabetics who were not using insulin. We assessed all study withdrawals pre-randomization and post randomization and sought information on the reasons for discontinuation of all participants.

To measure the differential between groups in attrition we used the relative attrition (RA), which is equivalent to relative risk but uses attrition as the outcome (i.e. attrition in intervention group/attrition in control group). We determined the percentage drop outs for control and intervention groups and used DerSimonian and Laird random effects models to estimate a pooled relative attrition. L'abbe type plots created in R (version 2.0.2) were used to represent the difference in the relative attrition among the trials with 95% confidence areas and weights derived from the random effects model.

Results

With self-monitoring of blood glucose in type 2 diabetes, attrition ranged from 2.3% to 50.0% in the intervention groups and 0% to 40.4% in the control groups. There was no significant difference between the intervention and control, with an overall RA of 1.18 [95% CI, 0.70–2.01]. With self-monitoring of oral anticoagulation attrition ranged from 0% to 43.2% in the intervention groups and 0% to 21.4% in the control group. The RA was significantly greater in the intervention group, combined RA, 6.05 [95% CI, 2.53–14.49].

Conclusion

This paper demonstrates the use of relative attrition as a new tool in systematic review methodology which has the potential to identify patient, intervention and trial characteristics which influences attrition in trials.

Self-management of oral anticoagulant therapy: A systematic review and meta-analysis

BACKGROUND

A number of randomized controlled trials have compared self-management of oral anticoagulant therapy with conventional management. However, the results have not appeared consistent and a systematic review and meta-analysis are therefore needed in order to evaluate self-management of oral anticoagulant therapy. The aim of this study was to evaluate the efficacy and safety of self-management of oral anticoagulant therapy for patients on long-term oral anticoagulant therapy.

METHODS

A systematic review and meta-analysis including randomized controlled trials with highly selected patients comparing self-management of oral anticoagulant therapy with conventional treatment. Data were extracted in terms of study characteristics, quality of trials and outcome (death, minor and major complications (thromboembolic and bleeding events), and time within therapeutic INR target range).

RESULTS

Ten trials with a total of 2724 patients were included. Two of the trials could be classified as high quality trials. Considering all trials, self-management was associated with a reduced risk of death (relative risk (RR)=0.48, 95% confidence interval (CI) 0.29-0.79, p=0.004), major complications (RR=0.58, 95% CI 0.42-0.81, p=0.001) and with increasing time within therapeutic INR target range (weighted mean difference=6.53, 95% CI 2.24-10.82, p=0.003). No clear effect was found regarding minor complications (RR=0.98, 95% CI 0.49-1.99, p=0.96).

CONCLUSIONS

A majority of the existing trials have various methodological problems. However, self-management of oral anticoagulant therapy appeared at least as good and possible better than conventional management in highly selected patients.

Reducing medical costs and improving quality via self-management tools

The authors consider the advantages and limitations of self-management tools used for treating chronic illness.

Management of atrial fibrillation

Atrial fibrillation (AF) is a condition of genuine clinical concern. This arrhythmia increases patient morbidity and mortality, most notably due to stroke, thromboembolism and heart failure. Consequentially, there is a strong impetus to acquire a greater understanding of its natural history and course in order to provide crucial evidence-based treatment and resource allocation in the future. The objective of this review article is to present a concise overview of the management of AF, with reference to the recent evidence-based National Institute of Clinical Excellence (NICE) National Clinical Guidelines for the management of AF.

Patient self management of oral anticoagulation in routine care in the UK

BACKGROUND

Self management of anticoagulation: a randomised trial (SMART) was the first large scale UK trial to assess clinical and cost effectiveness of patient self management (PSM) of oral anticoagulation therapy compared to routine care. SMART showed that while PSM was as clinically effective as routine care, it was not as cost effective. SMART adds to the growing body of trial data to support PSM; however there are no data on clinical effectiveness and cost of PSM in routine care.

AIM

To evaluate clinical effectiveness of PSM compared to routine care outside trial conditions.

METHODS

A retrospective multicentre matched control study. 63 PSM patients from primary care in the West Midlands were matched by age and international normalised ratio (INR) target with controls. INR results were collected for the period 1 July 2003-30 June 2004. The primary outcome measure was INR control.

RESULTS

38 PSM and 40 control patients were recruited. INR percentage time in range was 70% PSM vs 64% controls. 60% PSM were having a regular clinical review, 45% were performing an internal quality control (IQC) test and 82% were performing external quality assurance (EQA) on a regular basis.

CONCLUSION

PSM outside trial conditions is as clinically effective as routine UK care.

Self- versus conventional management of oral anticoagulant therapy: effects on INR variability and coumarin dose in a randomized controlled trial

BACKGROUND

Comparison of self-management of oral anticoagulant therapy versus conventional management has been hindered by use of different methods. We tested the hypothesis that there is no difference in the International Normalized Ratio (INR) variability, INR level, and coumarin dose among patients randomized to conventional management versus self-management.

METHODS

The study design included uniform analysis of blinded control blood samples in both treatment arms. Ninety-two patients were randomly assigned to either self-management of oral anticoagulant therapy (including a teaching program for self-management followed by 6 months of independent self-management) or 6 months of conventional management. The endpoints were the variance (median square of the standard deviation) of the INR value, the median INR-value (using a blinded control sample analyzed monthly by a reference laboratory), and the coumarin dose.

RESULTS

Self-management was associated with a statistically significant smaller variance in INR values, a higher median INR value, and a higher dose of warfarin compared with conventional management. No difference was found in the group of patients using phenprocoumon.

CONCLUSION

Training and implementation of patient self-management leads to a smaller variance in INR values, a higher median INR value and a higher dose of coumarin compared with results obtained for conventionally managed patients.

Patient self-management of anticoagulation therapy: a trial-based cost-effectiveness analysis

Demand for anticoagulation management is increasing due to an expansion of clinical indications for therapy. One possible model of care to meet demand is patient self-management (PSM), beneficial to patients who need control over their condition. This study aimed to determine the cost and cost-effectiveness of PSM of anticoagulation compared with routine clinic-based care for patients receiving long-term anticoagulation. A cost-utility analysis was conducted alongside a randomised controlled trial; 617 patients were recruited and followed up for 12 months. There was no significant difference in mean quality-adjusted life years (QALYs) between groups - after adjusting for baseline, the mean difference in QALYs was 0.009 (95% CI, -0.012 to 0.030). Overall mean healthcare costs in the PSM arm were significantly higher at pounds sterling 417 (CI pounds sterling 394- pounds sterling 442) compared with pounds sterling 122 (CI pounds sterling 103- pounds sterling 144) in the control arm. Therefore, using a formal cost-effectiveness analysis, PSM of anticoagulation does not appear to be cost-effective. However, PSM may have other benefits in relieving pressure on traditional clinic-based care, and the cost-effectiveness of this model of care for some subgroups of anticoagulation patients needs to be explored further.

The risks of warfarin use in the elderly

The use of warfarin in the elderly, particularly for stroke prevention in chronic atrial fibrillation, is steadily increasing. Although the benefits of warfarin are greatest in the elderly, so are the risk of adverse outcomes and the difficulties of anticoagulant management. Clinical systems need to improve to counter this therapeutic dilemma, as warfarin is likely to remain the only widely available oral anticoagulant for the foreseeable future. Aspects that require attention are: the careful selection of patients in whom treatment with warfarin is appropriate; initiating therapy in a low dose (e.g., 2.5-5 mg/day); thorough education of patients and carers; close monitoring, especially with any change in the patient's regular drug therapy; involving patients more in the management of their warfarin therapy (self-monitoring/management in suitable patients); and ongoing review of the appropriateness of therapy as circumstances change.