What are NNT and NNH?

And Why You Should Care

The number needed to treat (NNT) and number needed to harm (NNH) are important concepts that helps you weigh the benefits and harms of a treatment. NNT is the number of people that need to be treated in order to help one person benefit from a treatment.  For example, for a sinus infection the NNT is 15, meaning 1 in 15 people who took antibiotics recovered faster.  The number needed to harm is the number of people who will be harmed by the treatment.  For that same sinus infection the NNH is 8, meaning 1 out of every 8 people suffered side effects from the medication.  Understanding these numbers may help guide you to a more informed decision about taking antibiotics versus watching and waiting.

On a quest to help all of us understand this concept and to provide clear data on the NNT, a great team of physicians built a database that compiles the NNT and NNH of many therapies and screening tests.  This is an excellent website to browse to more fully understand if you really should ask for that antibiotic for a sinus infection or bronchitis.

There was a recent article in the New York Times about the NNT and NNH that is very helpful if you want more detail.  Also the group that built the NNT database made a video with a very detailed explanation of these concepts.

Please use these tools to help you more fully understand the benefits and risks of the treatments proposed to you by your doctor.  Encourage your doctor to run through this with you so you can make an informed decision about what is right for you. The more we push our health care providers to give us clear information about treatments, the better off we will all be.