Oral Anticoagulation Patient Self-Testing: Consensus Guidelines for Practical Implementation - Part 2

Oral Anticoagulation Patient Self-Testing: Consensus Guidelines 
for Practical Implementation

Rationale for wider 
implementation of PST

Comparative studies of PST and PSM as an adjuvant to usual care

Patient INR self-testing by those who receive oral anti-coagulant therapy with warfarin is an effective tool for monitoring therapy and managing dose adjustments. Many clinical studies have demonstrated significant reductions in the risk of bleeding and thrombotic complications when PST is added to a comprehensive care plan, and these management tools are commonly used in several European countries. As an adjuvant to standard medical management by health care practitioners or anticoagulation clinics, weekly INR testing with PST, in addition to the office-based medical evaluation and management provided by primary care practitioners, has been shown to result in better INR control, lower rates of bleeding and thrombotic complications, and superior patient satisfaction. The Centers for Medicare and Medicaid Services (CMS) evaluators noted that within the large body of data collected from randomized controlled trials demonstrating consistently favorable results for PST, no trials have shown a decrease in time in therapeutic range with self-testing (CMS 2008). A summary of selected studies of PST/PSM supporting this claim is presented in Table 1.

PST costs and related 
reimbursement

Recent changes in the reimbursement system in the United States have made implementation of PST feasible for a wider range of patients receiving oral anticoagulant therapy and for their health care practitioners. In 2002, CMS approved reimbursement for home INR SUPPLEMENT / ORAL ANTICOAGULATION 3 monitoring for patients with mechanical heart valves. In March 2008, CMS expanded coverage to patients with AF and VTE, including deep vein thrombosis (DVT) and pulmonary embolism (PE) (CMS 2008). This decision is supported by the Ameri can Heart Association, the American Stroke Association, the American College of Cardiology, and the American College of Clinical Pharmacy.

The CMS decision states several conditions for reimbursement eligibility, including the patient’s need for chronic oral anticoagulation with warfarin, at least 3 months of therapy prior to beginning PST, successful completion of a face-to-face training program and correct demonstration of device operation, continued proper use of the device in the context of a comprehensive management plan, and a testing frequency of no more than once weekly. The CMS decision was based on 10 clinical studies demonstrating that home testing is associated with consistently higher rates of time in therapeutic range and improved patient outcomes, regardless of the clinical indication or type of INR device used. Among the advantages related to the immediate availability of weekly results with PST, CMS lists:

• 
The ability of the health care practitioner to make dose adjustments quickly

• 
The ability of the patient to correlate lifestyle factors to INR stability

• 
Increased confidence on the part of the practitioner to prescribe sufficient doses of warfarin to achieve the therapeutic range (CMS 2008)

Reimbursement is approved for PST-related services in addition to the standard fees for management of patients. Currently, the payment for review of each set of 4 PST results is $9.08; for providing one-time initial device training (described in more detail on page 7), $191.20; and for leasing an INR device and providing testing supplies to the patient, $140.54 per month (Table 2, page 4).

Practitioner options

Practitioners who implement PST as part of a patient’s overall management plan may choose only to review and evaluate the additional INR results provided by PST, and ask patients to purchase their own devices and supplies and receive device training through a licensed, third-party vendor. Alternatively, they may choose to review results and provide patients with initial device training, but require that they obtain their device and supplies through the third-party vendor. A third option is for the practitioner to review results, purchase the INR devices and then lease them to patients, and make test strips and other supplies available to patients. Table 2 (page 4) shows the PST reimbursement for three different levels of practitioner involvement.

Cost-effectiveness

The benefits that have been demonstrated by the addition of PST to the usual care model include greater time in therapeutic range, fewer dose changes, reduced risk of bleeding and thrombotic complications, improved survival, and improved quality of life for patients (Ansell 1995, Ansell 2005, Sawicki 1989, Koertke 2007). In addition, several studies have determined that there are significant cost savings for the health care system associated with the decreased incidence of adverse events related to warfarin therapy. Lafata (2000) calculated a cost-effectiveness ratio of $24,818 per avoided adverse event with PST, compared with anticoagulation clinic management alone. This figure, which reflects costs for the year 1997, includes all direct medical costs and patient and caregiver costs related to PST and utilization of care that would be required for treatment of a hemorrhagic or thrombotic event. In a long-term follow-up of the effects of PST, Ansell (1995) determined that patients who self-tested required 50 percent fewer dose adjustments compared with patients in the control group. Both the increased time in therapeutic range and the decrease in required dose adjustments were statistically significant (both P<.001). In addition to the efficacy and safety implications of PST, there may be an advantage for practitioners in terms of less time and effort required to manage patients who achieve tighter INR control through PST.