A $2 solution for blood clot prevention after knee surgery

Blood Clot Prevention

Sometimes, the answer to a complicated medical challenge isn’t complicated at all.

In the case of the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI), an analysis of 30 months of data from Michigan patients having total knee transplants found that aspirin worked as well as anticoagulants to prevent blood clots after the procedure.

“There are tens of thousands of people in Michigan who have had total knee replacement surgeries. Not everyone is an appropriate match for aspirin therapy, so even if we switched half of these people to aspirin, we would save $6 million each year in drug costs,” says Brian Hallstrom, MD, co-director of MARCQI.

That’s because aspirin costs pennies a day, or roughly $2 total for a month of post-surgical blood clot prevention. Compare that to a standard month-long course of anti-coagulants that can cost anywhere from $380 to $890.

“Patients taking anticoagulant medication like Warfarin also must monitor blood levels, so there is the extra cost and resources for lab testing,” says Rochelle Igrisan, MBA, MSN, RN, senior project manager for MARCQI.

The collaborative analyzed data from 41,537 Michigan patients undergoing total knee replacement from April 1, 2013 to October 31, 2015. The analysis found:

  • 30.9% received aspirin only
  • 54.5% received anticoagulants only
  • 13.0% received both aspirin and anticoagulants
  • 1.6% received no blood clot prophylaxis

The primary total knee replacement patients who got only aspirin for their blood clot prevention had an equivalent incidence of blood clot or death and an equivalent bleeding rate with those on anticoagulants. The results have recently been published in JAMA Surgery.

As part of the MARCQI registry, the collaborative has collected information from a total of 141,822 total knee and total hip cases as of the end of 2016. There are 58 hospitals and two outpatient surgery centers across the state that participate in the collaborative and contribute data to the registry.

The group is studying a variety of ways to improve patient safety and the quality of hip and knee joint replacement procedures in Michigan, with five-year results that include:

  • Reducing the need for blood transfusions, from 10 percent to 1 percent, a savings of $4 million annually
  • Reducing the unnecessary discharge to a skilled nursing facility after surgery, from 21.5 percent to 10 percent, a savings of $20 million annually
  • Reducing blood clots by 40 percent.

In addition, the group conducts surveillance of hip and knee implants, and evaluates their risk for revision surgery. They also conduct patient surveys, and have been able to use patient-reported outcomes to develop ways to reduce their post-surgical pain.

“Our goal is to make Michigan the best place in the world to have a joint replacement. We’re making great progress,” says Dr. Hallstrom.


  • Reducing the need for bood transfusions, from 10 percent to 1 percent, a savings of $4 million annually
  • Reducing the necessary discharge to a skilled bursing facility after surgery from 21.5 percent to 10 percent, a savings of $20 million annually
  • Reducing blood clots by 40 percent