You might freak out when you realize how likely it is that your medication will do you no good.
There’s a very important term in medicine that is often ignored, it is “Number Needed to Treat.”
It means, how many people have to take the medication for one of them to avoid the bad outcome.
For example – why do people take Lipitor?
- So they don’t have a heart attack or stroke and then die or become seriously impaired.
What does Lipitor do?
- It lowers cholesterol
Why lower Cholesterol?
- To avoid clogging arteries.
Why avoid clogged arteries?
- To prevent a heart attack or stroke
Why prevent a heart attack or stroke?
- to prevent death or serious impairment.
How many people have to take Lipitor to prevent one of them from dying or becoming seriously impaired?
Okay – forget death or impairment, let’s just talk about a heart attack
How many people have to take Lipitor to prevent one of them from having a heart attack?
- 100. Yeah. One hundred people have to take Lipitor for 3 years in order to prevent one heart attack.
And Lipitor isn’t the worst drug, not by far.
Zetia is also taken to lower cholesterol – but it’s NNT is so high it isn’t shown to prevent any heart attacks at all. Over 1000 people have to take it just to avoid heart disease.
How about aspirin? Its NNT is 350.
Well what about exercise? What is exercise’s NNT for preventing a heart attack?
- 3. For every three people who exercise regularly, one of them will be saved from having a heart attack.
All of these number are speaking about healthy people, but it’s still poor even for those who already have disease.
Take people who already have heart disease or have had a heart attack. How many of them have to take Lipitor to prevent one heart attack? 20.
You’ve had a heart attack, is it worth the 1 in 20 chance to pay for and take a pill every single day?
You just have high blood pressure, is it worth the 1 in 250 chance then? Is it worth $500-$1000 per year to take a pill that has a 1/250 chance of helping you?
Okay - forget the money. What about the side effects? Lipitor can cause diarrhea, muscle pain, nausea, headache, etc… Is it worth it to take a pill knowing that the only effect it will most likely have is negative?
Remember, Lipitor is one of the BEST drugs that way. It's side effects are fairly mild and what it prevents is fatal. Even so, with such a small chance of benefit, is it worth it?
My point is this. Medications cost money and they have side effects. They work, but not nearly as well as most people think. They bring peace of mind, they correct lab values, and for a small number of people, they prevent a bad outcome.
I am not callous or disinterested. I prescribe medications every day with this knowledge. I know my own family history and I’m going to be watching my cholesterol levels like a hawk the rest of my life. Nevertheless, it is disheartening to know that for the HUGE majority of people taking medication, it will have no positive effect in their life whatsoever.