Patient Self-Management Improves Oral Anticoagulation Control
By Sally Beattie, MS, RN, CS, GNP
Summary—Inadequate control of oral anticoagulant therapy is often associated with serious consequences, including hemorrhage, thromboembolism, and even death. A randomized, single-blind, multicenter trial evaluated the effect of self-management of oral anticoagulation therapy on accuracy of control and quality of life.1 Using a device similar to those used to monitor blood sugar levels, 179 subjects participated in the study. Study subjects received three small-group education sessions enabling them to assess and manage their anticoagulation medication titration at home. Study controls received routine outpatient care. Investigators found that international normalized ratio values within target range in self-management subjects increased from <29% at baseline to 57% at three-month and 53% at six-month follow-up. There was little change in the percentage of controlled patients within target range between baseline (36%), three-month (34%), and six-month (43%). Quality-of-life scores also were significantly higher in the intervention group (4.21), compared with routine care controls (2.96). Researchers concluded that patient education in self-management of anticoagulation therapy improves accuracy of control as well as treatment-related quality-of-life measures.
The management of oral anticoagulation is fraught with difficulties for both patient and provider. The risk of serious hemorrhage, as well as the labor-intensive and frustrating nature of patient management, presents major obstacles to optimal clinical outcomes. Chief among the identified factors affecting unstable control of anticoagulant therapy are poor patient compliance with prescribed strategies and misunderstandings related to health care counseling. In other chronic disease states such as diabetes and hypertension, self-monitoring and self-adjustment of medication dosage coupled with structured patient teaching programs has led to major improvements in patient compliance, medical outcomes, and quality of life. To these ends, a group of German researchers conducted a randomized, single-blind, multicenter trial investigating the effects of patients’ self-management of oral anticoagulation therapy on accuracy of control and quality of life measures.1
Study Design
Investigators recruited 179 patients receiving long-term oral anticoagulation therapy with phenprocoumon, an anticoagulant derivative of 4-hydroxycoumarin similar to warfarin.2 Study inclusion criteria included:
• Subjects were not treated by the participating health center prior to the study.
• Subject’s disease or condition was expected to require lifelong anticoagulation.
• Subjects were randomized to a control or intervention group. After randomization, all patients underwent examinations of baseline prothrombin (PT) and international normalized ratio (INR).
Control subjects received the usual outpatient care consisting of unstructured information about oral anticoagulation, diet, adverse effects, and twice-monthly visits to an outpatient facility. The intervention group underwent three consecutive weekly 60-90 minute small-group teaching sessions covering all aspects of oral anticoagulation management. Study subjects were encouraged to control their anticoagulation level by self-monitoring 1-2 times/week using a finger-prick capillary whole blood PT/INR monitor.
Coagu-Chek is manufactured by Boehringer Mannheim of Mannheim, Germany, and Roche Diagnostics of Indianapolis. Coagu-Chek is used similarly to home instruments for checking blood-sugar levels.3 Education and models for adjusting anticoagulant medication doses were taught, and subjects were instructed to contact the teaching center in case of difficulties. (For components of the study’s self-management teaching plan, see box, p. 35.)
Study subjects underwent follow-up examinations of PT and INR at three and six months to determine positive or negative differences between INR value and the INR target range established by the treating physician prior to the study. All patients were informed of the target range. Most patients with prosthetic heart valve replacement had INR target ranges of 3.0-4.0, 3.0-4.5, or 2.5-3.5, while those with atrial fibrillation had an INR target range of 2.0-3.0. In some patients, a narrower INR range, e.g. 3.0-3.5, was set. Target ranges were recorded in the patient’s logbook at baseline and remained unchanged throughout the study.
Treatment-related quality-of-life was assessed with a 40-item structured questionnaire covering five treatment-related topics: general treatment satisfaction, self-efficacy, strained social network, daily hassles, and distress.1 (A copy of the questionnaire is available from the study’s author. See note at end of story.)
Encouraging Outcomes
Evaluation of the study results showed that INR values at baseline were within target range in less than 29% of self-management subjects. The percentage increased to 57% on the three-month and 53% on the six-month follow-up. The percentage of controlled patients did not change significantly between baseline and three-month follow-up (36% and 34%, respectively), but showed a slight increase (43%) thereafter in the routine care group. In addition, INR values were within the target range more often. On follow-up, quality-of-life scores indicating general treatment satisfaction also were significantly higher in the intervention group (4.21), compared with routine care controls (2.96).
One event of major bleeding occurred in each group, while 12 and 10 minor bleeding episodes occurred in the intervention and control groups, respectively. Two major nonfatal embolic events (myocardial infarction and ischemic stroke) occurred in the routine care group.
Researchers concluded that patient self-management of oral anticoagulation based on a structured teaching and INR value self-monitoring program is safe and leads to improvement of accuracy of anticoagulation control and related quality-of-life issues. They acknowledged that the study was too small and too short to assess the effect of self-management on bleeding and embolic complications. Similar outcomes have been identified in other retrospective and prospective studies using a home capillary whole blood monitoring device.4,5,6 Researchers in all of these studies concur that larger prospective studies are needed to further define the applicability of these devices.
Implications for Practice
The use of a home-monitoring device to manage anticoagulant therapy appears to be emerging as a safe and effective strategy for achieving improved outcomes in appropriately selected patients. However, at present, it has both advantages and disadvantages to consider.
Disadvantages: The important issue of cost-effectiveness has yet to be determined. The price of the Coagu-Chek monitor is $1,295. A box of 15 test strips costs $6, while the control strips cost $20 per box.7
Interestingly, Medicare benefits currently do not reimburse for the use of these devices due to their classification as experimental. Private insurance payers, including Blue Cross/Blue Shield, Prudential, and Aetna, reimburse 75% of the cost.7
Advantages: Many patients who require long-term anticoagulant therapy are older, and the need for less travel to a facility may make the difference in better compliance and accuracy of control. Although the current cost of the monitor might be prohibitive, the initial cost may be offset by decreased utilization of expensive and limited resources in patient visits to health care providers and laboratory testing facilities.
The importance of patient satisfaction cannot be over emphasized. The empowerment gained by assuming control of one’s care may serve as the most important rationale for selecting this mode of care in the near future.
(Editor’s note: To obtain a copy of the Treatment-Related Quality-of-Life Questionnaire, contact: Peter T. Sawicki, MD, PhD, Department of Metabolic Diseases and Nutrition, Heinrich-Heine University, P.O. Box 10 10 07, D-40001 Dusseldorf, Germany. E-Mail: Sawicki@med.uni-duesseldorf.de.)
References
1. Sawicki PT, for the Working Group for the Study of Patient Self-Management of Oral Anticoagulation. A structured teaching and self-management program for patients receiving oral anticoagulation. JAMA 1999; 281:145-50.
2. DRUGDEX System’s Drug Evaluation Monographs: Phenprocoumon. Micromedex Inc. © 1974-1999;99:1-90. See www.micromedex.com.
3. Van den Bresselaar AMHP, Breddin K, Lutze G, et al. Multicenter evaluation of a new capillary blood prothrombin time monitoring system. Blood Coagul Fibrinolysis 1995;6:726-32.
4. Ansell JE, Patel N, Ostrovsky D, et al. Long-term patient self-management of oral anticoagulation. Arch Intern Med 1995;155:2185-89.
5. Ansell J, Holden A, Knaple N. Patient self-management of oral anticoagulation guided by capillary (fingerstick) whole blood prothrombin times. Arch Intern Med 1989;149:2509-11.
6. Anderson DR, Harrison L, Hirsh J. Evaluation of a portable prothrombin time monitor for home use by patients who require long-term oral anticoagulant therapy. Arch Intern Med 1993;153:1441-47.
7. Boeringer Mannheim Roche Diagnostics booth, American College of Cardiology 48th Scientific Sessions. New Orleans; March 7-11, 1999.