NNT and NNH are Two Medical Terms I Never Heard
NNT and NNH are Two Medical Terms I Never Heard
Why don’t doctors share these stats?
Has your doctor ever suggested a pill to you and reassured you with something like “There are some possible side effects, but most people tolerate it well?”
I’d be surprised if you said no.
My doctor said something like that to me recently. I was seeing him to complain about getting up too often at night to pee, something that had became more annoying when I reached my seventies. After testing, prodding, and interrogation, my doctor decided that there was nothing wrong with me other than getting older, but offered a pill called “Mirabegron” to cut the urination frequency.
This article is not about Mirabegron and is not offering medical advice. I have no medical training and I did not take this pill. This is about finding more information about any pills your doctor may suggest.
In other words, Mirabegron is treating the symptom, not any particular problem. I shrugged, accepted the prescription, but looked it up on WebMD when I got back home. WebMD told me that Mirabegron may cause nausea, dizziness, fast heartbeat, runny or stuffy nose, headaches, and elevated blood pressure. More rarely, it can cause burning or painful urination, rashes, itching, swelling of the face, tongue, throat, severe dizziness, and trouble breathing.
Wow. But the Doc said most people said most people tolerate this medicine well and side effects were “pretty benign”. So even if you read all that, you might shrug and think, “Doc said benign, I’ll probably be fine.”
If you make it rhyme, you’ll feel fine.
I might have thought the same thing were my oldest daughter not friends with a Doctor Patrick Neustatter. She mentioned that he had written a book called “Managing Your Doctor” that she thought I’d like. She described her friend as bright, empathetic, and amusing, so I bought the book and have been reading it. That same day I came across two medical terms in his book that you may never have heard of: NNT and NNH. Those are common abbreviations for some important statistics, Number Needed to Treat and Number Needed to Harm.
You can find NNT and NNH numbers for most drugs through Google, though you may have to look up the brand or chemical name when searching. Finding this statistic can help you decide whether or not to take the drug.
A simple search for “Mirabegron NNT” may find lots of matches, but they’ll usually be buried in thick medical studies that I’d hope my doctor might understand, but I certainly do not. I’m stubborn though, and after wading though a good deal of printed material with headache inducing side effects, I found something that told me the NNT for Mirabegron ranged from 6–12 in that particular study.
What’s that mean? It means that 1 in 6 to 1 in 12 patients were helped by the drug.
Let that sink in. It means that taking this drug may not work at all. Works or not, you have a risk of side effects, some quite nasty, and that’s the NNH number. Searching for NNH was even more difficult than getting the NNT; I finally found that it might be about 5. A low NNH isn’t great, 5 means one in five will be harmed. One in five means a 20% chance.
I think it’s pretty obvious why these numbers are hard to find. Drug companies likely don’t want you to know them. Doctors may not want those numbers to scare you away from a medicine you need. I can understand that, though I’d rather have the numbers to discuss with my doctor than foggy warnings from WebMD.
There’s also some fogginess in these NNT and NNH stats. This article points out that they don’t necessarily tell the whole story:
The Numbers Needed to Treat and Harm (NNT, NNH) Statistics: What They Tell Us and What They Do Not
Article Abstract Research papers and research summaries frequently present information in the form of derived…
Whole story or not, I think it’s better than getting even less information, although some doctors obviously would disagree. The same doctors might not have warm fuzzies about WebMD either. I found other articles with a much more positive view of these stats.
I looked up numbers for statins because my wife takes one of those and is experiencing muscle pain, one of the more common side effects. Because there is some controversy over whether people like her get any benefit from statins, she’d like to give them up. I checked WebMD first and found this:
Should I Take a Statin for High Cholesterol?
Statins are drugs that lower "bad" cholesterol. What else should you know? WebMD explains.
Again, no hard numbers, but a suggestion that maybe she shouldn’t take, so I googled more and found TheNNT.com, which is obviously a site for doctors, because it’s nearly impossible to know what to search for inside the site. Searching from outside is better, at least for those of us lacking deep medical knowledge. Using the google trick of searching for “site:thennt.com statins” found nothing, but “site:thennt.com cardiovascular disease” gave me this:
Statins in Persons at Low Risk of Cardiovascular Disease — TheNNT
No statistically significant mortality benefit 1 in 217 avoided a nonfatal heart attack (myocardial infarction) 1 in…
Take a quick peek. Wow, nice graphic, isn’t it? High NNT, so a low number of people helped, and NNH of 21, meaning that 1 in 21 using statins experienced pain from muscle damage. Muscle *damage*, I noticed. I gave these two links to my wife; she plans to talk about all of this with her doctor. You should never stop taking a pill without talking to your doctor. It also makes sense to discuss any pill where the stats are putting you off. Your doctor might know that the possible benefits far outweigh the risks in your specific case.
I decided not to take the Mirabegron. My annoyance at being dragged from sleep is fairly low and I’d rather not risk the side effects. I told my doctor that and he agreed with my decision.
As noted, these numbers can be hard to find and your doctor may think they are not useful. I think they are useful, and wish they were easier to find. If you are a person who’d prefer to have these numbers, all I can tell you is to be stubborn and creative.
The truth is out there. Or if not the truth, at least some stats.
Please do leave a comment. Comments are payback by giving me and other readers new ideas. So disagree with me or point out something I missed — your thoughts matter!