Despite knowing a more accurate way to describe the effectiveness of medicine, drug companies insist on advertising a drug’s effects in terms of “relative risk.” This term inflates the drug’s value, leading consumers to frequently purchase and consume medicine that may not help them.
For example, in 1995, a journal published an article stating that a certain cholesterol-lowering drug had a 31% relative reduction in the risk of heart attacks amongst users. This drug quickly became one pharmaceutical company’s highly profitable drug, grossing over $2 Million a year. While the drug did have a 31% relative reduction rate, it only had a 2.2% absolute reduction rate.
To best understand the way the statistics mislead consumers, consider this example: 100 people with high cholesterol took the drugs. Of them, 93 would not have had a heart attack regardless of the drug. 5 of the 100 have heart attacks despite taking the drug. Only the remaining 2 out of the original 100 avoided a heart attack by taking the drug. Here, 100 people underwent treatment to avoid 2 heart attacks. So, the number of people who must get the treatment for a single person to benefit is 50. This statistic is known as the “number needed to treat” or “NNT.”
The NNT statistic methodology was developed in 1988 as way for consumers to make smart purchasing decisions. However, drug companies refuse to use it in their advertising or labeling. The cholesterol drug highlights its 31% reduction and neglects to even mention the NNT.
Making decisions based on relative risk reduction is not a huge problem when the costs are low. For instance, wearing a seat belt forces no cost upon the consumer and the individual benefit of treatment may be low. However, when consumers are choosing whether or not to buy a very expensive drug, the use of the reduction rate statistic is deliberately misleading and misleads directly into the pockets of drug companies.