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Apixaban (Eliquis) is likely cost-effective for atrial fibrillation (Afib) patients, despite the higher cost than generic warfarin, according to an economic analysis of the ARISTOTLE trial.

Over 2 years, anticoagulant therapy was almost six times pricier with apixaban ($6,166 versus $1,181 with warfarin, P<0.001), although other cumulative healthcare costs did not differ between apixaban and warfarin groups ($15,686 versus $15,746, P=0.96), reported , of Duke Clinical Research Institute in Durham, N.C., and colleagues.

Apixaban cost an extra $53,925 over warfarin per quality-adjusted life year. In their paper appearing online in JAMA Cardiology, Cowper's group argued that this had a 98% likelihood of meeting a .

"Apixaban therapy for ARISTOTLE-eligible patients with Afib provides clinical benefits at an incremental cost that represents reasonable value for money judged using US benchmarks for cost-effectiveness," the authors reasoned. "Results were generally consistent when model assumptions were varied, with lifetime cost-effectiveness most affected by the price of apixaban and the time horizon."

Based on the main ARISTOTLE outcomes data, apixaban raised quality-adjusted life expectancy compared with warfarin (7.94 versus 7.54 quality-adjusted life years, P<0.001).

Clinical outcomes with apixaban "were improved sufficiently to provide reasonable value in the setting of the US system," according to , of California's Stanford University School of Medicine.

"This increase in life expectancy of 0.4 years (5 months) may not seem like much, but it's actually rather substantial in the context of cost-effectiveness analysis. Another way to interpret this number is that it equals the effect of having one more patient survive out of every 19 patients treated, with an average life expectancy of 7.54 years."

But do cost savings associated with reduced monitoring, less bleeding, and fewer strokes offset apixaban's high price tag?

"Over 2 years of follow-up, the patients in the ARISTOTLE trial assigned to apixaban therapy had, as expected, lower costs of prothrombin time monitoring, but this savings offset only 15% of the cost difference between apixaban therapy and warfarin therapy. They also had fewer hospital admissions for bleeding and for stroke, but these events were infrequent; reducing them saved only 6% of the higher cost of apixaban," he wrote in an accompanying editorial.

"These modest cost savings were partly counterbalanced by higher medical costs during the extra years of life in the apixaban-assigned patients and dwarfed by the high background costs of medical care of patients with atrial fibrillation. As a result, downstream cost savings did not materially offset the higher cost of apixaban therapy, and using it will significantly increase net costs."

"The economic analysis of the ARISTOTLE trial suggests that using apixaban therapy instead of warfarin therapy for patients with Afib will increase healthcare costs because the savings from reduced monitoring, bleeding, and stroke are small compared with the higher cost of purchasing apixaban," Hlatky concluded.

ARISTOTLE included 18,201 Afib patients randomized to apixaban or warfarin and followed for a median of 1.8 years, from 2006 to 2011. The economic analysis only looked at the 3,417 participants from the U.S. (mean age 71 years, 68.2% men, 95.5% white).

Among the limitations of the study was the fact that costs were not directly incorporated into the ARISTOTLE dataset; the value of health services was determined using externally-derived means.

"Clearly, while NOACs [non–vitamin K oral anticoagulants] meet current thresholds for cost-effectiveness (relative to warfarin) from the perspective of the healthcare system, medication choice when starting or continuing anticoagulation must depend on the clinical and economic risk profiles of individual patients," Cowper and colleagues noted.

"An additional consideration is the distribution of the financial burden of NOACs relative to their clinical benefit across the healthcare sector, as responsibility for affected service areas, such as formularies, anticoagulation clinics, and stroke rehabilitation, may be spread across multiple entities."

According to the investigators, the additional monthly out-of-pocket expense for NOACs ranges from $2 to $130 among Medicare and Medicaid enrollees.

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