NNT: Your Defense Against Modern Pharmaceutical Snake Oil Sales Tactics

Many popular pharmaceuticals are presented as miraculous cures when, in fact, they have much lower effectiveness than the sellers claim. As a result, most of us believe most medicines to be far more potent than they are and assume they have fewer side effects than in reality. We may be more likely to accept a prescription than not, by default, based more on faith in the results than the true knowledge of their effectiveness. 

The term "Snake Oil" refers to a medical solution that is promoted as a cure-all for various illnesses but is fake and worthless. A snake oil salesman sells these useless products for a quick profit and then escapes to avoid the consequences. Many of these were salespeople who traveled from place to place selling their goods. Regrettably, these individuals frequently focused on vulnerable groups such as the elderly and those who are unwell. 

Some things never change. You may have noticed the numerous medication ads and cover stories on the news that make them sound so wonderful. Are the medications as effective as they say? The answer is, sadly, usually no.

 Let's take the Covid vaccines as an example. They said they would stop Covid in its tracks with 95% certainty. They said if you got the vaccine, you wouldn't get the virus or spread it; thus, it would end the pandemic. They said it was safe. Unlike in days when people were free to refuse to buy the product, the government and giant corporations became snake oil salespeople and coerced citizens into receiving the Covid vaccines. How did they get away with this? Read on to find out.

Relative risk reduction

Let's take the imaginary virus called cooties19 that kills .01 percent of the people who get sick with it. 99.9 percent of people who get cooties19 will live. So a drug that stops all people from dying of cooties19 will only be effective at saving .01 percent of the people who have cooties19, or one life in a thousand. Relative risk reduction tactics ignore the 999 people who would never benefit from taking the drug. They would live no matter what they did, including taking the drug that saves lives from cooties19. Relative risk says that the one person in a thousand who would have died did not, so the drug becomes described as 100% effective! Relative risk reduction, although a recognizably viable statistical tool, is a snake oil sales tactic. 

Absolute Risk Reduction

Absolute risk reduction is a much more accurate way of determining the effectiveness of a medication. Let's use the above sample of cooties19 to illustrate absolute risk reduction. We can take 2000 people and break them in half into a control and experimental group where one gets a placebo, and the other gets the medication. We already know that only one in 1000 will die in the placebo group, and nobody will die in the experimental group receiving the medication. The risk of dying without the medication is .01 percent, and the risk of dying in the group receiving the medication is zero. Lowering the risk from .01 to zero gives us an absolute risk reduction of just .01 percent!

NNT to the Rescue

There is a way of understanding how effective medicine is for individual patients. It is a simple statistical concept called the number needed to treat or the NNT. The NNT rates the impact of a medicine or therapy by estimating the number of patients that need to be treated to have a positive outcome on one person. 

Not everyone is helped by a medicine or intervention; some benefit, some are harmed, and some are unaffected. One of the challenges in treatments is that it's difficult to predict which group a person receiving treatment will fall into - those who benefit, those who experience harm, or those who are unaffected. This uncertainty makes it a complicated process. 

Suppose disease X kills 75% of people with it, meaning 25% survive without medication. Now suppose there is a treatment that, when taken, results in 50% survival. 25% would have survived anyway, and an additional 25% survive with the medication, making the medicine appear to work 50% of the time. The NNT, or the number of people needing to take the medication before one person benefits, is 2. The lower the number for the NNT, the better. 

Now let's look at cooties19 again. 999 out of 1000 survive the disease without intervention, and all 1000 survive with treatment. The NNT is 999, a high number, indicating a small chance of any benefit. 

The NNT Website

Thankfully, a free website called The NNT does all of the calculations to help us decide whether a treatment is right for us. Remember that it is not intended to diagnose or treat any condition. It is meant to be a straightforward communication of the science that can help us understand the likelihood of whether we will be helped, harmed, or unaffected by treatment. Let's look at statins, one of the most prescribed medications they cover. Statins are prescribed for people with known heart disease to prevent heart attacks, strokes, and death. They studied how many of these people would need to take a statin for five years before one life was saved, and the NNT came out to 83. You can see their results in green. That means statins have a 1.2 percent chance of saving a life of someone with known heart disease over five years. Next, they looked at how many non-fatal heart attacks were prevented and came up with an NNT of 39. That means statins are 2.5 percent likely to help prevent survivable heart attacks in people with heart disease. Lastly, the NNT for stroke prevention was 125, or .8 percent. 

For people with no known heart disease (high cholesterol is not considered heart disease, only a risk factor, and a poor one at that) no lives were saved, which means the NNT is infinity. See their red chart to the right.

They also give us the numbers on side effects. For statins, the NNT for developing diabetes is 50, or 2 percent. The NNT for muscle damage is 10, or 10 percent. Based on the numbers, only the individual can decide whether they want to take the medication. If the patient is OK with a 1.2 percent chance of having their life saved while assuming a 2 percent chance of developing diabetes, and a ten percent chance of developing muscle damage in the process, then they will choose to take a statin. On the other hand, if the moderate ten percent risk of muscle damage weighed against low 1.2 percent effectiveness against death seems risky, they may choose a different treatment.  

Snake Oil Versus The NNT

If the numbers regarding statins are surprising, you are not alone. When I looked at The Mayo Clinic's website on statins, they gave no information about their effectiveness. I found the same for The Cleveland Clinic's website for statins. Finally, Lipitor, one of the more popular statins, is presented on its official website, Lipitor.com, with no statistics. I am not claiming that these websites state anything false. They don't give the most useful information, which is the actual effectiveness of the medication. They rely on popular misconceptions about their true effectiveness. That is why The NNT is invaluable when deciding whether a medication or procedure is right for you. Stay away from the sales pitches. Better decisions are made when all of the facts are understood.