How to Analyze the Safety of Prescription or Over-the-Counter Drugs
Did you know that every drug that you are prescribed by your medical doctor or can purchase over-the-counter goes through randomized controlled trials to determine its benefits. The measurement used to determine treatment benefits is called the number needed to treat, or NNT.

Number Needed to Treat (NNT)

 The number needed to treat refers to the number of patients who need to be treated in order to prevent one bad outcome, such as heart attack or stroke. So, if a drug has an NNT of 10, it means you have to treat 10 people with the drug to prevent one person from having a bad outcome. The ideal NNT is 1. This means that every patient who is treated will benefit. But, this is hardly ever the case with drugs. In fact, the NNT for many drugs is often very high.
Number Needed to Harm (NNH)

Another number you need to know is the NNH — or number needed to harm. This indicates how many patients need to be exposed to a risk factor for it to cause harm to one patient who would not otherwise have been harmed. The lower the NNH, the worse the risk factor.
Studies reported by The on statins given over a five-year period to people with no known heart disease is a good example of why you need to be aware of the NNT and NNH for any drug. Over 5 years, the NNT for statins showed that no patients had their lives saved. In addition, only one patient in 104 had a heart attack prevented, and only 1 in 154 had a stroke prevented. However, these same studies showed that 1 in 100 were harmed because they developed diabetes as a direct result of stains, and 1 in 10 developed muscle damage as a direct result!

 The report on statins also summarizes that the risk of harm may still be underestimated and that diet and lifestyle interventions are substantially more powerful than medication in protecting your heart and preventing heart attacks and strokes!

 You can also look to NNT for some popular non-drug therapies. For example, The reports that 95% of patients with infectious diarrhea who were given probiotics had the duration of their diarrhea decreased by 25 hours where the duration of the control group was between 2-7 days. Probiotics also decreased the proportion of patients with diarrhea lasting longer than 4 days from 45% to 19%. This means there is an NNT of 4. Finally, there were no adverse effects reported. So a NNH of 0!

For more information on NNT, you can go to the therapy review page and look up therapy reviews by specialty. Use this to help you determine whether a drug is right for you.


Restoring Your Health Naturally

Dr. Kellie Seth, D.C.

Call 651.439.3737

Healing River Chiropractic in Stillwater