NNT: The Benefit of a Drug - or Not
We have seen in the previous two articles the tremendous impact of antibiotics in combatting disease and saving lives. And we have seen how abusing antibiotics has spawned antibiotic resistant organisms that take lives with the impunity of bacteria in the pre-antibiotic age.
Pharmaceutical drugs have exploded in number, dominating advertising and contributing to ever increasing medical expenditures. Are we healthier as a result?**
Whether a drug (or herbal) is going to help us or not is an extremely valuable piece of information. Yes, muscle testing (kinesiology) will give us the answer, but for those who want a “scientific” answer, we turn to statistics: the NNT – Number Needed to Treat.
Actually, the NNT will not predict with certainty that YOU will be helped by the prescription, but it does give the probability of being helpful to you (down to ZERO for bisphosphonates for bone density, below). If you take medication, what is the probability that you will benefit?
There is a website that lists some of the more popular drugs and natural therapies and lists their NNT for a specific health issue.
For example:
Those numbers are great if you are the 1 beneficiary of 5 years of statins, not so great if you are one of the 38 who took them faithfully for 5 years and did not benefit – you did not have a non-fatal heart attack whether you took the statin or not.
And how do you factor in that 3 or 4 of those 38 (the statistic is exactly 3.8) suffered muscle damage (one of the main side effects causing discontinuation)? How do you factor this and other side effects such as diabetes, memory loss, lower hormones, etc., into the equation?
Look at the NNT for some of these popular medications. Many of these are very low probability of helping (1 in over 100), many are still not likely to be helpful (1 in over 10), and in the remainder, the odds get better (1 in less than 10, or a better than 10% chance that the drug will achieve the end point.
Somehow, this does not seem to jive with the pharmaceutical ads. Let’s see why.
Let’s say in a study of 1000 people over a certain period of time, 20 are expected to die from a heart attack. If only 10 die on the medication instead of 20, the drug is responsible for a 50% reduction in heart attacks. Pretty impressive statistic! (But remember what Mark Twain said about statistics….)
Now if we look at the Number Needed to Treat in this example:
NNT = 1000 people medicated/10 people saved = 1000/10 = 100. Or you could see it as 1% (10/1000) of the people on the drug benefitted.
The difference between 1% and 50% is pretty huge.
What negative health effects did the 99% (990 people in this case) incur because of the drug? (We won’t even talk about the extra cost, time, and hassle with the health insurance company.)
Nobody actually lied – it’s just statistics.
So let’s look at a real drug, Fosamax, and an article on the AARP website. After giving some details, the article clarifies what has been written:
“Of the thousands of women in the study group, 1.0 percent of those taking Fosamax experienced hip fractures, compared with 2.2 percent of those taking placebo (sugar pills). Because 1.0 percent is 44 percent of 2.2 percent, Merck is allowed to say that its drug reduces bone fractures by 56 percent. The same study reported that, among postmenopausal women without osteoporosis, the relative risk of hip fractures actually went up 84 percent with Fosamax treatment.”
Wait, the article gets even better!
“What's more, a systematic review of 33 studies of bisphosphonate drugs published last year by the highly respected Therapeutics Initiative found "no statistically significant reduction in hip or wrist fracture" in women with no previous fractures or vertebral compression — who make up the majority of women treated with bisphosphonates. In higher-risk women, the review found small reductions in absolute risk — 1 percent for hip fractures and 1.3 percent for wrist fractures, noting that even those statistics are based on "a potentially biased subset" of patients in the studies. Plus, neither the doctors who prescribe bisphosphonate drugs nor the companies that manufacturer them are able to say how long patients should be taking them.”
And the article mentions the side effects possible for all of those people who saw no benefit from the drug:
“Moreover, bisphonate drugs may have adverse side effects, such as:
So, Fosamax “reduces bone fractures by 56 percent” in the Fosamax study, but that is not what we find in later studies. We look at bisphosphonates, in general, on the NNT website and find:
Bisphosphonates for Fracture Prevention in Post-Menopausal Women Without Prior Fractures
In Summary, for those who took the bisphosphonates:
Benefits in NNT
Bisphosphonates for Fracture Prevention in Post-Menopausal Women With Prior Fractures or With Very Low Bone Density
In Summary, for those who took the bisphosphonates:
Benefits in NNT
Time and chance do happen to us all, but taking unnecessary chances tips the odds in favor of “chance” instead of “time.”
To extend a healthier time in life, we improve our chances by taking care of the body. The body has the wisdom to care for itself if it is given the right resources and not burdened with those things that are harmful.
Next article
**Note: This article, like all others in these e-newsletters and website, is provided as an information resource only, and is not to be used or relied on for any diagnostic or treatment purposes. This is not a substitute for medical advice. If you have a health condition requiring treatment, please consult a healthcare professional.
We have seen in the previous two articles the tremendous impact of antibiotics in combatting disease and saving lives. And we have seen how abusing antibiotics has spawned antibiotic resistant organisms that take lives with the impunity of bacteria in the pre-antibiotic age.
Pharmaceutical drugs have exploded in number, dominating advertising and contributing to ever increasing medical expenditures. Are we healthier as a result?**
Whether a drug (or herbal) is going to help us or not is an extremely valuable piece of information. Yes, muscle testing (kinesiology) will give us the answer, but for those who want a “scientific” answer, we turn to statistics: the NNT – Number Needed to Treat.
Actually, the NNT will not predict with certainty that YOU will be helped by the prescription, but it does give the probability of being helpful to you (down to ZERO for bisphosphonates for bone density, below). If you take medication, what is the probability that you will benefit?
There is a website that lists some of the more popular drugs and natural therapies and lists their NNT for a specific health issue.
For example:
- For a specific issue (e.g. heart disease prevention);
- a specific group of people (people with known heart disease);
- the drug (statins);
- for a specific period of time (5 years)
- endpoint = death (saved 1 life for every 83 people with known heart disease taking a statin)
- Therefore, NNT (the number of people treated to save one life) = 83
Those numbers are great if you are the 1 beneficiary of 5 years of statins, not so great if you are one of the 38 who took them faithfully for 5 years and did not benefit – you did not have a non-fatal heart attack whether you took the statin or not.
And how do you factor in that 3 or 4 of those 38 (the statistic is exactly 3.8) suffered muscle damage (one of the main side effects causing discontinuation)? How do you factor this and other side effects such as diabetes, memory loss, lower hormones, etc., into the equation?
Look at the NNT for some of these popular medications. Many of these are very low probability of helping (1 in over 100), many are still not likely to be helpful (1 in over 10), and in the remainder, the odds get better (1 in less than 10, or a better than 10% chance that the drug will achieve the end point.
Somehow, this does not seem to jive with the pharmaceutical ads. Let’s see why.
Let’s say in a study of 1000 people over a certain period of time, 20 are expected to die from a heart attack. If only 10 die on the medication instead of 20, the drug is responsible for a 50% reduction in heart attacks. Pretty impressive statistic! (But remember what Mark Twain said about statistics….)
Now if we look at the Number Needed to Treat in this example:
NNT = 1000 people medicated/10 people saved = 1000/10 = 100. Or you could see it as 1% (10/1000) of the people on the drug benefitted.
The difference between 1% and 50% is pretty huge.
What negative health effects did the 99% (990 people in this case) incur because of the drug? (We won’t even talk about the extra cost, time, and hassle with the health insurance company.)
Nobody actually lied – it’s just statistics.
So let’s look at a real drug, Fosamax, and an article on the AARP website. After giving some details, the article clarifies what has been written:
“Of the thousands of women in the study group, 1.0 percent of those taking Fosamax experienced hip fractures, compared with 2.2 percent of those taking placebo (sugar pills). Because 1.0 percent is 44 percent of 2.2 percent, Merck is allowed to say that its drug reduces bone fractures by 56 percent. The same study reported that, among postmenopausal women without osteoporosis, the relative risk of hip fractures actually went up 84 percent with Fosamax treatment.”
Wait, the article gets even better!
“What's more, a systematic review of 33 studies of bisphosphonate drugs published last year by the highly respected Therapeutics Initiative found "no statistically significant reduction in hip or wrist fracture" in women with no previous fractures or vertebral compression — who make up the majority of women treated with bisphosphonates. In higher-risk women, the review found small reductions in absolute risk — 1 percent for hip fractures and 1.3 percent for wrist fractures, noting that even those statistics are based on "a potentially biased subset" of patients in the studies. Plus, neither the doctors who prescribe bisphosphonate drugs nor the companies that manufacturer them are able to say how long patients should be taking them.”
And the article mentions the side effects possible for all of those people who saw no benefit from the drug:
“Moreover, bisphonate drugs may have adverse side effects, such as:
- Musculoskeletal pain; gastrointestinal problems: ranging from heartburn, acid reflux and other relatively mild gastrointestinal events to, in rare cases, chronic inflammation and ulcerations.
- Spontaneous bone fractures; and jawbone deterioration.”
So, Fosamax “reduces bone fractures by 56 percent” in the Fosamax study, but that is not what we find in later studies. We look at bisphosphonates, in general, on the NNT website and find:
Bisphosphonates for Fracture Prevention in Post-Menopausal Women Without Prior Fractures
In Summary, for those who took the bisphosphonates:
Benefits in NNT
- None were helped (fracture prevented after 3 years of medicine)
- A small number were harmed
Bisphosphonates for Fracture Prevention in Post-Menopausal Women With Prior Fractures or With Very Low Bone Density
In Summary, for those who took the bisphosphonates:
Benefits in NNT
- 1 in 20 were helped (vertebral fracture prevented)
- 1 in 100 were helped (hip fracture prevented)
- A small number were harmed
Time and chance do happen to us all, but taking unnecessary chances tips the odds in favor of “chance” instead of “time.”
To extend a healthier time in life, we improve our chances by taking care of the body. The body has the wisdom to care for itself if it is given the right resources and not burdened with those things that are harmful.
Next article
**Note: This article, like all others in these e-newsletters and website, is provided as an information resource only, and is not to be used or relied on for any diagnostic or treatment purposes. This is not a substitute for medical advice. If you have a health condition requiring treatment, please consult a healthcare professional.
