The “Absolute Truth” about warfarin replacement drugs

Publication Date: 
Mon, 02/03/2014
By: Alere Staff

The decision to choose warfarin or one of the new warfarin replacement drugs, (referred to as novel-anticoagulants or new oral anticoagulant drugs, NOACs) is difficult. There are many variables in making this decision. The most important variable is the drug’s ability to protect you against stroke, heart attack, bleeding and loss of life. While the media would have you think that warfarin replacement drugs are far better (superior) than warfarin – the truth will surprise you…and maybe your doctor.

A careful analysis recently published in the website Medscape by board certified cardiologist, electro-physiologist and internal medicine physician John Mandrola, MD. Dr. Mandrola, found warfarin and any of the new non-monitored drugs clinically equivalent.1 In fact, there was a better than 99% chance of no incremental benefit from moving away from warfarin. You will however be paying up to 50 times more than the cost of warfarin.1

So why are commercials and print advertising promoting the new agents as far better than warfarin? The answer is in how the data is presented. The use of “relative risk” vs. “absolute risk” is the difference and important for you and your doctor to understand when choosing which drug you’ll be taking.

Relative risk is used to compare the risk of experiencing an adverse event (like stroke or bleed), in people not receiving the new medical treatment (or drug) versus people who are receiving an established (standard of care) treatment.2 Absolute risk looks and compares actual events that took place in patients actually receiving treatment (drug).

The decision to pay up to 50 times more for convenience while the absolute clinical difference of less than 1% is ultimately up to you and a discussion with your doctor.1

Dr. Mandrola states that the highest quality decision making between patient and caregivers should include absolute risks and benefits not relative risk benefits.1

  1. Novel Oral Anticoagulants vs Warfarin: The Truth is Relative. Medscape. Dec 18, 2013.
  2. Irwig L, Irwig J, Trevena L, et al. Smart Health Choices: Making Sense of Health Advice. London: Hammersmith Press; 2008.