Management Of Oral Anticoagulants Research Articles

Self management of long term oral anticoagulation was as effective as specialist anticoagulation clinic management

Self management of long term oral anticoagulation was as effective as specialist anticoagulation clinic management

Oral anticoagulation self-management and management by a specialist anticoagulation clinic: a randomised cross-over comparison

Vitamin K antagonist treatment is effective for prevention and treatment of thromboembolic events but frequent laboratory control and dose-adjustment are essential. Small portable devices have enabled patient self-monitoring of anticoagulation and self-adjustment of the dose. We compared this self-management of oral anticoagulant therapy with conventional management by a specialist anticoagulation clinic in a randomised cross-over study. 50 patients on long-term oral anticoagulant treatment were included in a randomised controlled crossover study. Patients were self-managed or were managed by the anticoagulation clinic for a period of 3 months. After this period the alternative strategy was followed for each patient. Prothrombin time (expressed as international normalised ratio [INR]) were measured at intervals of 1-2 weeks in both periods without knowledge of type of management. The primary endpoint was the number of measurements within the therapeutic range (therapeutic target value +/-50.5 INR units). There was no significant difference in the overall quality of control of anticoagulation between the two study periods. Patients were for 55% and for 49% of the treatment period within a range of +/-0.5 from the therapeutic target INR during self-management and anticoagulation clinic management, respectively (p=0.06). The proportion of patients who spent most time in the therapeutic target range was larger during self-management than during anticoagulation clinic-guided management. The odds ratio for a better control of anticoagulation (defined as the period of time in the therapeutic target range) during self-management compared with anticoagulation clinic-guided management was 4.6 (95% CI 2.1-10.2). A patient-satisfaction assessment showed superiority of self-management over conventional care. Self-management of INR in the population in this study is feasible and appears to result in control of anticoagulation that is at least equivalent to management by a specialist anticoagulation clinic. It is also better appreciated by patients. Larger studies are required to assess the effect of this novel management strategy on the incidence of thromboembolic or bleeding complications.

Is the international normalised ratio (INR) reliable? A trial of comparative measurements in hospital laboratory and primary care settings.

AIM: To determine the reliability of international normalised ratio (INR) measurement in primary care by practice nurses using near patient testing (NPT), in comparison with results obtained within hospital laboratories...

Outpatient management of venous thromboembolism.

Low molecular weight heparins (LMWHs) have provided the necessary pharmacologic tool to facilitate the outpatient management of selected patients presenting with acute venous thromboembolism. A growing collection of clinical trial results supports the safety and efficacy of this cost-efficient management strategy. However, this approach requires careful patient selection and meticulous care planning. Several randomized multicenter trials have compared a primarily outpatient approach to treating uncomplicated proximal venous thrombosis with a LMWH administered subcutaneously once or twice daily to the inpatient use of unfractionated heparin (UFH). The results have been very encouraging and suggest that the use of subcutaneous LMWH in highly selected, uncomplicated venous thrombosis patients is as safe and effective as intravenous UFH, and that most patients can be treated as outpatient or be discharged early. Irrespective of parenteral anticoagulant approach, warfarin therapy was commenced on day 1 and continued for 3 months. A recent publication by Dedden and colleagues describes a 1-year experience with a pharmacy-managed program for the home treatment of patients presenting with proximal deep vein thrombosis. A plan for coordinated patient care was implemented which included a process for patient referrals, standardized protocol orders, a plan for holding area processing and home healthcare agency follow-up, and subsequent oral anticoagulation management. Results of the program demonstrate a significant healthcare savings (as compared with standard inpatient management) with no significant compromise in patient outcomes. Recently published trials by the Columbus Investigators and Simonneau and colleagues have looked beyond uncomplicated proximal venous thromboembolism to include patients presenting with recurrent venous thrombosis and pulmonary embolism. Results suggest the subcutaneous use of LMWH is as safe and effective as intravenous UFH. Such data begin to lay the scientific foundation for the expanded clinical base of patients who may be candidates for an outpatient management approach. In today's cost-conscience environment, managing the treatment of select venous thromboembolism patients with LMWH(s) and warfarin therapy in an outpatient environment represents an evolving approach that is economically logical, does not compromise patient outcomes, but requires considerable planning to address a myriad of logistical issues.

Review of computerized decision support systems for oral anticoagulation management

Computerized decision support systems (CDSS) are available to assist clinicians in the therapeutic management of oral anticoagulation. We report the findings relating to CDSS for oral anticoagulation management of a primary-care-based systematic review which largely focused on near-patient testing. Seven papers were reviewed which covered four different systems. The methodology of these papers was generally poor, although one randomized controlled trial showed improved therapeutic control associated with computerized management compared with human performance.

Warfarin or Acenocoumarol: Which Is better in the Management of Oral Anticoagulants?

Warfarin is employed more frequently than acenocoumarol because of its longer half-life (36 h), theoretically providing more stable anticoagulation, and avoiding factor VII fluctuations that potentially occur during acenocoumarol treatment (half-life 10 h). The aim of our study was to compare acenocoumarol with warfarin in the same group of 103 patients who started oral anticoagulation with acenocoumarol and then changed to warfarin. In these patients we compared the previous period of six months on acenocoumarol treatment (July-December 1996) with a new six-month period on warfarin (July-December 1997). We wished to know whether warfarin could improve the quality and the stability of oral anticoagulation of our patients and whether there was a difference between the two drugs in the weekly mean dose per patient. Moreover in order to detect the possible daily fluctuation of factor VII, we evaluated a further group of 54 patients. A subgroup of these patients was treated with warfarin while another received acenocoumarol. In the first group of patients, 1,158 and 1,064 PTs were carried out with acenocoumarol and warfarin, respectively. The percentage of PTs in the therapeutic range was 59% with acenocoumarol and 62% with warfarin (p=0.4). The mean number of visits per patient was 12 and 11, and the mean number of visits in the therapeutic range was 7 and 7, respectively. The last check in file method did not show any difference between the two drugs. Overdose states were 51 (4.4%) with acenocoumarol and 30 (2.8%) with warfarin (p=0.4). A good correlation (r=0.92) was found between the acenocoumarol and the warfarin weekly mean dose. The mean warfarin/acenocoumarol weekly dose ratio was 2.08 (range: 1.25-3.30; CI 95%: 1.99-2.16). In the second group of patients, factor VII levels with both drugs were higher 24 h after administration than 16 h after, showing that their daily fluctuation was independent of the drug's half-life, since factor VII levels in patients with a low vitamin K intake were not increased. Our results showed that warfarin did not appear to be better than acenocoumarol in the performance of an Anticoagulation Clinic in terms of PTs within the therapeutic range per patient. It seems that the behaviour of factor VII was affected by the intake of vitamin K rather than by the short half-life of acenocoumarol.

The Value of a Specialized Program for the Management of Oral Anticoagulation

SummaryOral anticoagulation has proven to be an effective and useful therapy for over 50 years for patients at risk for thromboembolism, but recent evidence suggests that many patients are not only poorly managed, but therapy is withheld from a significant number of individuals because of the fear of complications and the labor intensiveness of treatment.Over the last decade several developments have occurred that may increase and improve the use of oral anticoagulation by effectively lowering the risk/benefit profile. Among these have been the standardization of the prothrombin time using the International Normalized Ratio leading to more appropriate and standardized therapy, and a number of consensus conferences in the United States and throughout the world focusing on indications for anticoagulation. Less has occurred in a coordinated fashion to substantially improve the management of oral anticoagulation until very recently. There is now accumulating evidence showing that a coordinated and focused approach to the management of therapy by specialized programs significantly improves clinical outcomes by improving therapeutic control, lessening the frequency of hemorrhage or thrombosis and decreasing the use of medical resources leading to more cost-effective therapy. Furthermore, with the development of new technologies for the measurement of prothrombin times (capillary whole blood PTs or point-of-care testing) allows for novel models of management including patient self-testing and patient self-management. These latter concepts are beginning to be popularized in several regions, especially Germany, Canada and the United States.The focus of the presentation will be to comment on the barriers to more effective and widespread use of anticoagulation and to summarize advances in the management of therapy including the concept of anticoagulation management services, patient self-testing and patient self-management.

Self management of oral anticoagulant therapy after heart valve replacement.

Patients with mechanical heart valves require lifelong oral anticoagulant treatment which entails frequent blood sampling and dosage adjustment. The purpose of this study was to investigate the feasibility of letting heart valve operated patients manage blood specimen analysis and dosage adjustment themselves. A total of 21 patients were enrolled in the study and followed for at least 9 months postoperatively. Immediately after the heart valve operation they were trained in operating a CoaguChek international normal ratio (INR) monitor to analyze capillary whole blood samples. Subsequently training in dosage adjustment was accomplished and all patients were considered fully capable of self management after 30 weeks. In the training period, parallel laboratory INR measurements were made at 3-4 week intervals for reference. A control group of 20 patients was matched, respectively, to the study group. The INR target range was 2.0-3.0. Out of the 21 study patients 19 continued self management beyond 9 months. The median INR value obtained with the monitor was within therapeutic target range for all study patients and only 15 out of 20 control patients were within this range. The mean systematic deviation between laboratory and CoaguChek INR was 7.8% but each patient had a constant characteristic deviation from -11 to +21%. The study patients were within therapeutic target range 77% of the time compared with 53% for the control patients. Self management of oral anticoagulation is feasible for selected patients and constitutes a significant service improvement compared with conventional management. The CoaguChek monitor seems sufficiently accurate and reliable for self testing and the treatment quality is comparable or even better than conventional management. Assessment of the rate of bleeding and thrombo-embolic events shall be settled in studies comprising larger number of patients.

Long-term Patient Self-management of Oral Anticoagulation

The management of oral anticoagulation is fraught with difficulties. This study assessed a new model of anticoagulation management regarding the ability, safety, and efficacy of patients to self-monitor and self-adjust the dose of their oral anticoagulants guided by a capillary whole-blood prothrombin time (PT) monitor. This investigation is a retrospective cohort study of 20 patients compared with 20 matched control patients receiving oral anticoagulation at a tertiary medical institution. Study patients monitored their PTs 2153 times during a mean interval of 44.7 months compared with 1608 PTs in matched control patients during a mean interval of 42.5 months. Study patients made an average of 11.5 dosage changes per patient, contrasted with 22.7 changes per control patient (P < .001). The PTs in study patients were within the recommended therapeutic range in 88.6% (95% confidence interval, 87.2 to 89.9) of the determinations compared with 68.0% (95% confidence interval, 65.7 to 70.3; P < .001) of the determinations made by the matched control patients. In response to the 2153 PTs, study patients made 67 (3.1%) dosage decisions that were considered incorrect based on physician guidelines. None of these changes led to adverse outcomes. There was no significant difference in complication rates between the two groups. Results from what is the first long-term study of patient self-monitoring of PTs and self-adjustment of the warfarin sodium dosage for oral anticoagulation suggest that patients can successfully measure their own PTs, adjust their own warfarin dosage, and achieve a degree of therapeutic effectiveness at least as good, if not better than patients managed in an anti-coagulation clinic. Larger, prospective, randomized trials are needed to confirm the efficacy and safety of this new approach to therapy and to assess its cost-effectiveness.

Long-term patient self-management of oral anticoagulation

Background : The management of oral anticoagulation is fraught with difficulties. This study assessed a new model of anticoagulation management regarding the ability, safety, and efficacy of patients to self-monitor and self-adjust the dose of their oral anticoagulants guided by a capillary whole-blood prothrombin time (PT) monitor. Methods : This investigation is a retrospective cohort study of 20 patients compared with 20 matched control patients receiving oral anticoagulation at a tertiary medical institution. Results : Study patients monitored their PTs 2153 times during a mean interval of 44.7 months compared with 1608 PTs in matched control patients during a mean interval of 42.5 months. Study patients made an average of 11.5 dosage changes per patient, contrasted with 22.7 changes per control patient (P<.001). The PTs in study patients were within the recommended therapeutic range in 88.6% (95% confidence interval, 87.2 to 89.9) of the determinations compared with 68.0% (95% confidence interval, 65.7 to 70.3 ; P<.001) of the determinations made by the matched control patients. In response to the 2153 PTs, study patients made 67 (3.1%) dosage decisions that were considered incorrect based on physician guidelines. None of these changes led to adverse outcomes. There was no significant difference in complication rates between the two groups. Conclusions : Results from what is the first long-term study of patient self-monitoring of PTs and self-adjustment of the warfarin sodium dosage for oral anticoagulation suggest that patients can successfully measure their own PTs, adjust their own warfarin dosage, and achieve a degree of therapeutic effectiveness at least as good, if not better than patients managed in an anti- coagulation clinic. Larger, prospective, randomized trials are needed to confirm the efficacy and safety of this new approach to therapy and to assess its cost-effectiveness.

Improving quality of care: clinical reasoning for and experiences with patient management of oral anticoagulation

Improving quality of care: clinical reasoning for and experiences with patient management of oral anticoagulation

Imprecision of prothrombin time monitoring of oral anticoagulation. A survey of hospital laboratories.

Prothrombin time monitoring of oral anticoagulation is highly dependent on the tissue thromboplastin used. In the United States, patients have received a higher level of anticoagulation because of the use of a less sensitive thromboplastin. Many advocate the use of an International Normalized Ratio to rectify this problem. Laboratory supervisors from all acute care hospitals in Massachusetts were surveyed to determine the disparity in thromboplastin use and reporting practices for prothrombin time testing. Eighty-eight of 103 (86%) hospitals responded. Fifty-eight lots from six manufacturers of thromboplastin were in use. The International Sensitivity Index of these lots ranged from 1.89 to 2.74. Ninety-nine percent of hospitals reported prothrombin times in raw seconds. Only 5% reported an International Normalized Ratio. Sixteen different coagulation instruments were in use. Close to 70% of laboratory supervisors had little or no understanding of the significance of an International Sensitivity Index or an International Normalized Ratio. The management of oral anticoagulation appears far less precise than had been believed. Prothrombin times in the same individual from different laboratories may have poor correlation. Based on the level of understanding of laboratory supervisors, extensive education will be necessary to change practices and improve accuracy and comparability of prothrombin time testing.

Patient Self-Management of Oral Anticoagulation Guided by Capillary (Fingerstick) Whole Blood Prothrombin Times

Physician management of long-term oral anticoagulation is labor-intensive and costly. Moreover, errors of communication may lead to complications. We assessed the ability of patients to regulate their own therapy based on fingerstick prothrombin times (PTs) in order to avoid these problems. Such management was made possible by the availability of a device capable of measuring a PT from a capillary sample of whole blood. Sixteen patients adjusted their warfarin therapy based on specially developed guidelines for a mean duration of 43 weeks (range, 8 to 92 weeks). Four hundred fifty-eight PTs were measured by patients at home during the entire study. Three hundred ninety-three were in therapeutic range and patients correctly continued their dosages. Of the 65 nontherapeutic PTs, patients made correct dose adjustments in 49 and incorrect adjustments in 16. These incorrect adjustments were minor and judged to be clinically insignificant. They often resulted from a misunderstanding of the dosage guidelines. Given the slow onset of warfarin's effect, the assessment of the PT on a weekly or biweekly basis, and the ability to refine dosage guidelines, these errors were not felt to represent a serious drawback to the concept of warfarin self-management. No complications of therapy occurred during the study. Although this mode of therapy needs further evaluation, this pilot study suggests that patient self-management is feasible and that this model of anticoagulant care offers the potential for improved care at reduced cost.

Cost Effectiveness of Monitoring Warfarin Therapy Using Standard Versus Capillary Prothrombin Times

The authors assessed the cost effectiveness of monitoring warfarin therapy guided by standard plasma prothrombin times performed on blood samples obtained by venipuncture versus prothrombin times performed on capillary whole blood samples obtained by fingerstick. Twenty patients receiving long-term oral anticoagulation had either standard or capillary prothrombin times determined every other week for eight weeks in a cross-over design. All time intervals were monitored, including receptionist, secretarial, nursing, phlebotomy, etc., and costs for all materials, procedures, and labor were calculated. The total cost per test by the capillary whole blood prothrombin time method was significantly less than by standard prothrombin time methods ($7.55 vs. $15.64) even though the nurse-patient encounter time was greater per test for the capillary method (12.4 minutes vs. 8.3 minutes). The management of oral anticoagulation guided by prothrombin times performed on instrumentation designed to sample capillary whole blood should result in a significant cost savings, and because of the immediate availability of results, provide the potential for improved health care.