Homing In on Oral Anticoagulation Performance Measures

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UGxhdGVsZXQyMDEwLTA4LTEwIDAxOjM0OjA4.jpg - blood, clot, vein, platelet
Many areas in medicine have received a lot of attention regarding their quality of care in terms of provider and facility performance. These include how sites and providers maintain proper hemoglobin A1c levels, as well as how they reduce cath lab complications and heart failure readmissions. However, data regarding the performance of anticoagulation management is scarce.

Anticoagulation control

Warfarin is the most widely used oral anticoagulant drug globally, with more than 30 million prescriptions written for it in the U.S. in 2004 (Arch Intern Med 2007;167:1414-1419).

While patients might research the physicians and hospitals to whom they will entrust their coronary stenting or bypass surgery, they rarely do so with those who will manage their warfarin therapy, says Adam J. Rose, MD, a general internist at the Center for Health Quality, Outcomes and Economic Research at the Bedford VA Medical Center in Bedford, Mass.

"The lifetime rate of serious complications for oral anticoagulation therapy is higher than for most commonly performed surgeries. Yet, ways to optimize anticoagulation outcomes requires more research," he says.

In fact, none of the approximately two dozen core measures and menu requirements for Stage 1 meaningful use of health IT involves anticoagulation control, Rose says. "This topic—performance measures associated with anticoagulation control—has not appeared on anyone's radar. If someone said that a particular surgical procedure had a high risk of morbidity, everyone would be rushing to measure it."

Defining quality of care

The problem with warfarin is not the problem of compliance per se, says Howard Herrmann, MD, director of interventional cardiology and the cardiac cath labs at the University of Pennsylvania Medical Center in Philadelphia. "The problem is that even when it is taken the way it's prescribed, the therapeutic effect varies, based on diet, the frequency with which adjustments are made based on blood tests and the frequency with which blood tests are obtained."

All patients, no matter how carefully and compliant they are with taking the drug, will inevitably have some highs and lows to their therapeutic level of anticoagulation. "Even in carefully controlled clinical trials, only about two-thirds of patients at any one time fall within expected therapeutic range," Herrmann says.

Connolly et al performed a post hoc analysis of the ACTIVE W trial (526 centers in 29 countries) to explore the variation in INR control, as measured by time in therapeutic range (TTR) (Circulation 2008;118;2029-2037). Although centers were encouraged to achieve a TTR greater than 60 percent, researchers found a wide variation, between 44 to 78 percent, with one-third of centers below the median TTR of 65 percent. Centers below the median TTR had worse outcomes (stroke, MI, vascular death or major bleed) than centers above the median TTR.

"The finding of a threshold below which oral anticoagulation benefits are diminished, or do not occur, points to a potentially useful program for improved quality of anticoagulation: Routine measurement of the center TTR for patients with atrial fibrillation and then corrective action if the TTR is less than 65 percent," Connolly et al concluded.

Rose agrees with Connolly et al that anticoagulation control is the best measurement of quality of care. "It's easy to abstract, calculate and understand; it varies among providers or sites of care; improvement is possible; and there is strong evidence linking it to important outcomes, such as stroke, venous thromboembolism and major hemorrhage," Rose says.

The problem with using TTR as a quality indicator is the absence of a risk adjustment model, which "can ensure that sites are being compared regarding quality of care rather than regarding merely differences in case mix," Rose and colleagues wrote (Circ Cardiovasc Qual Outcomes 2011;4:22-29).

The risk-adjusted model consists of many variables likely to affect TTR, including demographics, area-level poverty, driving distance to care, physical health conditions, mental health conditions, number of medications and number of hospitalizations. Researchers found difficult case mixes equally among the best- and worst-performing sites. They concluded, "Without risk-adjusted TTR, sites could claim that their poor performance was solely because of their case mix." The real culprit is low-quality anticoagulation control, Rose says.

In benchmarking for warfarin therapy, the "quality of care can be evaluated at different levels such as outcomes (e.g., INR results, major bleeding, thromboembolisms and death), processes (e.g., method used to adjust warfarin doses) and structures (e.g., clinic organization structure, workload statistics), according to Daniel M. Witt, senior manager of clinical pharmacy services at Kaiser Permanente Colorado (J Thromb Thrombolysis 2011;online Feb. 15).

"Even though warfarin has been used for decades, measurements defining what constitutes high quality warfarin therapy have not been formalized and widely adopted," Witt says. In fact, the Joint Commission this year outlined National Patient Safety Goals relating to anticoagulation therapy.

Among the Joint Commission's proposals is patient education. Pat Driscoll, RN, manager of the Cardiac Care Clinic at Louisville Cardiology Medical Group in Kentucky, says that she and her colleagues spend a lot of time educating patients. "We have a packet of information we give to patients, but it's generally not enough. We educate them every time they come in about diet, compliance, drug interactions and unusual symptoms."

Anticoagulation & IT

Many clinics use anticoagulation management software programs to help manage their patients. Rose says that these programs have been shown to improve oral anticoagulation care by making it easier to monitor patient care and outcomes. These programs often have decision support components that help manage dosing, as well as general record keeping and appointment reminders. They also can calculate anticoagulation control rates, which can help a clinic gauge its performance.

Last year, Louisville Cardiology merged with Baptist Hospital East in Louisville. Before the merger, the group used its EMR to help manage patients in the anticoagulation clinic, says Driscoll. Access to patients' EMR allowed Driscoll and her colleagues to see all the relevant data regarding a patient's anticoagulation control, including lab values, adverse reactions, unusual symptoms, compliant issues and return date. When patients missed their appointments, the EMR also generated letters, which were distributed to the patients as well as to their primary care physicians.

Until the clinic adopts the hospital's EMR, it is using a tool through a subscription service that is managed by an outside company. While it's not as comprehensive as the EMR, Driscoll says it helps them manage their anticoagulation patients. "Physicians can access the program through the internet and they approve the INR [international normalized ratio] parameters."

Driscoll and her two nurse colleagues see about 250 to 325 patients per week, usually 50 per day, but it can be as high as 100. They track their quality of care in terms of the number of patients within the therapeutic range per month, but they do not compare their performance with regional or national benchmarks, as no such registries exist.

Where do we go now?

Regarding outcomes measures, the consensus seems to be that oral anticoagulation control via TTR is a good benchmark, perhaps with a risk-adjusted model. Process measures that can be improved include better follow-up intervals, better decisions about when to change and not change warfarin dose and maintaining consistent INR measurement compliance. On the structural side, EMRs or other IT programs with decision support for dose changes have been found to impact quality of care.

"Ultimately, we will have an edifice of evidence about what site and practice characteristics predict better performance and then distill that into an intervention to improve anticoagulation control performance," Rose concludes.