NNT

[imoldernu]

Yesterday, DW and I attended a lecture on Nutrition. Part of the discussion concerned the subject of pharmaceuticals and introduced a term that was unknown to me. NNT = "number needed to treat".
Since then, I've spent several hours reading about and trying to understand the implications for our own healthcare. At first I was dismissive of the subject because I haven't seen it in headlines, but after some initial study, I'm not so sure.

Rather than trying to explain, I thought to throw the subject out to the forum, for viewpoints from those who have more expertise. In any case, a topic worth knowing about, particularly in light of the number of new drugs on the market, the recalls that have been made, and the warnings that have become obligatory in drug advertisements.

In short, NNT has to do with the mathmatically proven efficacy of different mediucines. A good place to start, is this 2008 article from Business Week, which is primarily directed to cholesterol medications, but gives a very broad overview towards to all phamaceuticals.

Do Cholesterol Drugs Do Any Good? - Businessweek

I'd wrap it up, very simply with this statement:
Drugs "do things that have effects", but do they help us live longer?

If the general tone of the article interests you, you may want to go to WIKI for more information... The article is deep into statistics and technicalities, but the bibliograpies at the bottom of the article go to specific studies that are enlightening to say the least.
Number needed to treat - Wikipedia, the free encyclopedia A companion wiki article is NNH...

My jury is still out, but weighing my experiences with Lipitor and Avandia, and DW's experience with Fosomax and Prolia, I am looking at the risk/reward factors. NNT appears to give a good indication of how much we can expect in terms of extending out life term. At the very least, it seems that the subject will take us a step beyond our doctor's recommendations.

 

[braumeister]

NNT can be a remarkably useful tool.
You may find some useful information here, too:
www.thennt.com

 

[rgarling]

+++ from the 1st article +++

DOING THE MATH

The second crucial point is hiding in plain sight in Pfizer's own Lipitor newspaper ad. The dramatic 36% figure has an asterisk. Read the smaller type. It says: "That means in a large clinical study, 3% of patients taking a sugar pill or placebo had a heart attack compared to 2% of patients taking Lipitor."

Now do some simple math. The numbers in that sentence mean that for every 100 people in the trial, which lasted 3 1/3 years, three people on placebos and two people on Lipitor had heart attacks. The difference credited to the drug? One fewer heart attack per 100 people. So to spare one person a heart attack, 100 people had to take Lipitor for more than three years. The other 99 got no measurable benefit. Or to put it in terms of a little-known but useful statistic, the number needed to treat (or NNT) for one person to benefit is 100.

Usually NNT is normalized to 1 year; so, in this case the 100 should be multiplied by 3.3 for NNT of 330. So, over a 1 year period, 330 people subject themselves to the possibilities of adverse reactions from the medication on the chance that 1 of them will benefit.

 

[imoldernu]

Alittle bit off topic, but some thoughts stemming from learning about NNT.

Coming back to the initial NNT concept of a statistical analysis for determining the best outcome possibility for diagnosis, treatment, and pharmaceuticals as well as the emphasis placed on early detection and the amount of money being spent...
It occurs to me that this might be a better measure and guide for the expenditure of medicare and healthcare funds.
The best place to spend the available dollars... based on the greatest benefit for all.

As we go through the discussions about the cost/reward benefits for things like mammograms or prostate PSA testing, and the thousands more decisions about the allocation of government and special interest monies from foundations etc... where choices are to be made.... Should the emphasis be grounded in the NNT number, and shouldn't the public and the adminstrators use this as a major gauge for building the most cost efficient framework for national healthcare?

This goes beyond the initial intent of the OP, but thinking through the process and the way the taxpayer dollars are spent, using the NNT as justification for budget based expenditures might well result in a more cost effective allocation of $$$ for prevention instead of treatment, or early detection instead of long term care.

Finding the right balance by providing monies for grade school lunches and extended physical fitness programs may well be more meaningful for politicians and corporations if standards of NNT (numbers needed to treat) were understood and accepted. As it is, these determinations come more from vested interests and lobbying from hospitals, doctors, pharmaceutical companies and providers, rather than from proven statistical economies of scale and life expectancies.

Nothing new here, but really, how much does the public or our legislators know about NNT? Given a choice for the most cost effective approach and consequent use of government monies, would the best results come from "fixing" AIDS, Obesity, Cancer, Heart disease, or Malaria? How would we know? Which Healthcare test is most cost effective in preventing long term treatment or early death... Colonoscopy. Mammogram, EKG, PSA, Pap smear?

As we look at the incredible rise of healthcare, doesn't it make sense to begin an analytical process for making the most cost effective decisions? How is it being done today?

 

[Chuckanut]

I would agree that numbers like NNT can help us make better decisions on health care.

How about this for a simple start: All drug advertising must prominently carry the NNT numbers for people who are helped by the drug, AND for people who will suffer the negative side effects of the drug.

 

[rgarling]

... using the NNT as justification for budget based expenditures might well result in a more cost effective allocation of $$$ for prevention instead of treatment, or early detection instead of long term care.

Focusing on treatment rather than prevention is a big problem, but I don't see that changing anytime soon.

 

[Rich_by_the_Bay]

NNT is "number needed to treat" and is generally considered to be one of the more helpful parameters (such as the old "P" values).

It reflects the number of patients who would need to be treated to prevent one additional bad outcome, calculated as 1/absolute risk reduction (using a 95% confidence interval).

It is a way of assessing the relative good and bad outomes of treating a group of patients.

 

[Chuckanut]

I looked up the NNT statistics on thennt.com that for people with no prior heart attack who have taken a statin for five years:

Prevent one heart attack = 1 in 60
Prevent one stroke = 1 in 268
Harmed by developing diabetes = 1 in 67
Harmed by developing muscle damage = 1 in 10

So, which is more cost efficient? Prevent a heart attack in one person, or prevent diabetes in 0.9 persons? Prevent a stroke in one person or prevent muscle damage in 27 persons?