In February 2016, BMJ, a medical journal based in the United Kingdom, published a report detailing the use of a faulty device in the Xarelto clinical trials. The Alere international normalized ratio (INR) monitoring device was used to measure blood clotting in patients taking warfarin during the ROCKET-AF clinical trials. The report reveals that the device was recalled 3 years after the trials due to a defect that dated back to 2002.
Alere issued two voluntary recalls of the INRatio INR monitoring device and testing strips in December 2014, after thousands of users reported issues with the device malfunctioning. The FDA released a Class I recall notice which stated that the device could deliver results that were significantly lower than laboratory testing methods. These lower measurements may have led patients to be prescribed higher doses of drugs like warfarin than medically needed, and could have ultimately increased the risk of bleeding events.
Alere reportedly confirmed that this issue dated back to 2002—nine years before the ROCKET-AF Xarelto trials were published. The BMJ report asserted that the defect could have made Xarelto appear safer to doctors and patients than warfarin in terms of the risk of bleeding.