There is a way to understand how much modern medicine has to offer individual patients. It is a simple statistical concept called the “Number-Needed-to-Treat”, or for short, the ‘NNT’. The NNT offers a measurement of the impact of a medicine or therapy by estimating the number of patients that need to be treated in order to have an impact on one person. The concept is statistical, but intuitive, for we know that not everyone is helped by a medicine or intervention — some benefit, some are harmed, and some are unaffected. The NNT tells us how many of each.
The NNT is an intuitive and simple way of estimating how likely it is that a treatment or medicine will help an individual person. And it turns out that the NNT for a drug or intervention is easily calculated from the results of any trial done on that drug or intervention. The NNT allows physicians and their patients to easily determine and discuss the likelihood that a patient will be helped, or harmed, or unaffected, by a given medication or procedure.
The NNT is run by a group of physicians who have developed a framework and rating system to evaluate therapies based on their patient-important benefits and harms.
Example # 1
Statins for Primary Prevention of Heart Attack and Stroke and Stroke
Primary prevention = preventing heart attacks and strokes in those who have not suffered a cardiovascular event
The best science shows that the use of statin drugs in primary prevention of heart attacks and strokes will not help the vast majority of people taking them. In fact, more people will be harmed than those that are helped. The NNT’s overall conclusion found “no benefits” after five years of therapy. Here are some of their findings:
- 98% saw no benefit from taking statins
- 0% were helped in terms of lives saved
- 0% were helped by preventing a non-fatal heart attack (1 in 104)
- 7% were helped by preventing a stroke (1 in 154)
- 0% were harmed by developing diabetes (1 in 100)
- 10% were harmed by muscle damage (1 in 10)
Example # 2
Statins for People With Known Heart Disease or History of Stroke
The NNT’s overall conclusion found that “benefits outweighed harms” in those with known heart disease or those with a history of stroke. Their findings include:
- 95% saw no benefit from taking statins
- 2% were helped in terms of lives saved (1 in 83)
- 6% were helped by preventing a non-fatal heart attack (1 in 39)
- 8% were helped by preventing a stroke (1 in 125)
- 0% were harmed by developing diabetes (1 in 100)
- 10% were harmed by muscle damage (1 in 10)
Although the benefits don’t seem very substantial, the NNT defends their conclusion by stating:
“As a public health measure, this suggests that statins may have an identifiable effect, because while the chances of any one individual being affected are small (19 out of 20 people who took the drugs for five years saw no effect), when one million people take them, roughly 45,000 people saw some benefit while another 6,000 may see a harm.”
Dustin Rudolph, The Plant-Based Pharmacist, has some good advice for anyone considering using statins (From page 30 of the book “The Empty Medicine Cabinet”)
“After reviewing the data on statin therapy, it is evident that anyone considering taking these medications examine them with due diligence. Have a thoughtful discussion on both the benefits and risks with your doctor. An informed decision can then be made, with careful deliberation on the known facts, as to whether or not you choose to use these medications”.
Example # 3
The NNT’s analysis of a Cochrane Review of 13 trials containing 966 participants showed a statistically significant symptom benefit in roughly 19% more people taking zinc than those taking placebo. This benefit seemed to accrue only for those taking the drug within 24 hours of the onset of their cold symptoms without any major adverse effects. Minor effects that included bad taste, dry mouth and nausea occurred in 8.3% of participants taking zinc.
Although positive benefits have been shown, the NNT has reservations of the overall quality of the research to date. So at this time, the NNT states that the current research data are inadequate or unclear:
“Overall, there appears to be a potentially promising benefit-to-risk ratio with zinc as treatment for the common cold. However, a large, randomized, adequately blinded high quality trial using an appropriate zinc preparation has, in our opinion, the potential to trump and thus replace these data”.
The NNT as a “Go To” site
The NNT is a very useful guide to use when contemplating treatment options. To me, the most surprising discovery is how limited the benefits are from the most effective treatments. That includes the Mediterranean Diet for people without known heart disease and for those with known heart disease. The benefits appear stronger than what statins provide, but not close to what Dr. Caldwell Esselstyn has achieved with his low-fat whole food plant based (WFPB) heart disease reversal diet. Both the Esselstyn diet and the Mediterranean diet cause no adverse effects, which can’t be said for most drug treatments.
I hope you never suffer from an ailment that would require you to consult the NNT. But no matter how healthy you eat, and how regularly you exercise and how persistent you are in avoiding unhealthy habits – shit happens. The NNT may help to keep it from hitting the fan.
Some additional NNT treatment ratings you may find interesting include:
- Aspirin to prevent first heart attack or stroke
- Aspirin for cardiovascular prevention after prior heart attack or stroke
- Probiotics for acute infectious diarrhea
- Probiotics for preventing c-difficile-diarrhea
- Tight glycemic control for type 2 diabetes over 5 years.
Stay healthy and Strong!
E Excerpt from Laurie Endicott Thomas’s amazing book Thin Diabetes – Fat Diabetes by clicking here!
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