Thought on Medicine – July 2016
[The opinions expressed in this column are those of Dr. Gallo and may not reflect the thinking of other providers in WFMA.]
On Statin Medications
The use of statins in heart disease, and to control cholesterol, is a very controversial topic both in the medical and lay communities. To throw light on this subject, I want to discuss the concept of Number Needed to Treat (NNT). For those with heart disease, the best NNT for a statin in the studies so far is 28. This means that one death will be prevented for every 28 people who use a statin daily for 5 years; the other 27 people do not benefit from the treatment. In fact, the other 27 could suffer side effects such as problems with memory and focus, muscle pain, elevated sugars, and rarely rhabdomyolysis (muscle breakdown leading to kidney failure and even death.) So for every 28,000 people with heart disease that take daily statin therapy, 1000 lives will be saved over 5 years.
Clearly from a population standpoint, it makes sense to treat heart disease with statins; but from an individual perspective it makes far less sense. Unless I undergo treatment with a NNT of 1 or 2, that treatment is unlikely to benefit me. A NNT of 3 means that 2/3 of those treated will not benefit from that treatment. Unfortunately, the likelihood of benefit from modern medicines in chronic diseases are very small, which makes the decision of taking or remaining on such treatment difficult for any individual.
The last point I want to make in this regard is that none of us know whether we have significant heart disease unless we have undergone a cardiac catheterization (an invasive procedure that shoots dye into the coronary arteries). So most people are treated with statins just because they have high cholesterol, or because they have another risk factor for heart disease such as diabetes. If you do not have heart disease then the best NNT for a statin is not 28, but 146. Recently an article in the British medical journal The Lancet put it another way – statins extend life on average by only 3 to 5 days!