
Why Medical Advice Seems to Change So Frequently - WheelsAtLarge
https://www.nytimes.com/2017/01/16/upshot/how-to-prevent-whiplash-from-ever-changing-medical-advice.html
======
rscho
In view of other comments, it seems useful to point out that credible evidence
is nonexistent in the medical field. I am an M.D. with 7y experience in the
clinics, have done my share of research, and i can assure you that "scientific
evidence" in medicine is a humongous s __*load of tampered data written by
people who have absolutely zero idea of what science is.

~~~
ploxiln
Come on now, there is a good amount of scientific evidence, doctors do know
some things ... it's just that, if you're not a decent doctor, you can't tell
the bullshit from the useful information.

My mother is a GP, but I'm a software engineer, so I'd like to make a software
metaphor.

The experts have come up with best practices and agile methodologies. If you
follow the Agile processes rigorously and use industry-standard tools ...
often the results are total crap, like the Military or the State of Virginia
spending 300M on an accounting software project over 5 years and then just
throw it away. I guess we don't know anything about software, do we?

Well, some of us do. Some of us are reasonable about how much various
techniques help, what the trade-offs are, the inherent uncertainties. Some get
good results fairly consistently. And it isn't by rigorously following Agile
Methodologies, it's more than that, you have to be thoughtful about the code
itself.

And, medicine is often like debugging a large complicated messy system. It
takes time, and many practitioners are a bit lazy. They have a lot on their
plate, the don't have the time to really dig in and figure out each case. They
guess, patch in a work-around, and move on.

But, frankly, western medicine has been massively useful, and I think we all
know that.

EDIT: and of course there's the hype cycle: everyone, especially those who are
managers or customers rather than practitioners, are looking for the secret,
the trick to getting good results. Before agile, it was object-oriented,
etc...

~~~
rscho
M.Ds know things, that's the point! Have we been trained for scientific
thinking? Absolutely, totally not. Test your mother on basic statistics and
scientific reasoning, and you will quickly see the limits. This has absolutely
nothing to do with being a decent doctor or not. Now, you are going to tell me
she can read the scientific literature and make sense of it? Medicine is
caring for patients, meaning applying knowledge. Knowledge applied in the
clinics is mostly passed through practical training from generation to
generation. Arguably, the decisive factor of change in medicine has up to now
always been technology: a stent in an artery, ether anesthesia, organ
transplant, etc. A certain base of irrefutable knowledge is present, of
course, but it is proportionally small compared to the amount of downright
false information we get from clinical trials.

We could debate for hours on that subject, but I dare say that someone who
believes that most M.Ds can do real science is very wrong. Statistics done by
M.Ds is akin to a junkie cooking meth. He knows how to make it, but has no
idea why sometimes it goes wrong. Moreover, you drastically underestimate the
dishonesty of the "experts" you are citing.

~~~
Fomite
MDs are not the only ones doing medical research.

~~~
rscho
That is indeed a valid point. Unfortunately, most of biology can also be
qualified of "soft science". I however expect that a new age is coming for
medicine: the age of science (the real one, this time). We are already seeing
the birth of sizable databases exploited by professional scientists, but this
is still a very minor part of the research output, and the signal-to-noise
ratio is currently dismal. Additionally, the progress of medicine is somewhat
parallel to the progress of hard science. What is lacking the most, is solid
data and the methods to collect them.

~~~
Fomite
Ironically enough though, "hard scientists" wandering into biology and
medicine and going "Right, time to show you lot how _real_ science is done..."
are notorious for producing really awful research.

------
kbutler
Science: Observe. Generate hypothesis. Design experiment(s) that would
invalidate hypothesis. Test. Evaluate. Repeat as needed. Apply, and measure
effectiveness. Continue to evaluate as new data is gained.

Scientism: observe. Generate hypothesis. Apply.

It's not just medicine, but basically anything that tries to assert
credibility by being "science-based", rather than "proven".

~~~
didibus
The belief that proven exists is the bigger problem.

Things are proven mathematically within a single model, nothing in reality is
proven. There is only a scale from models that are more useful and likely to
give us what we want, and models that are less likely.

But, things can be disproved. So if we have a single case against a model, we
know it does not hold 100%. The model is then insufficient.

In that sense, we need to know: are the medicinal models presented to us known
to not be the most useful and likely to help us? If they're not, then they're
still valuable, and we should be happy that we're improving them at a high
pace, giving us the impression previous models were wrong, yet models are not
wrong, just less useful and likely to help us, but if it was still the best we
had, your chances were still better following it.

~~~
wott
"But it's been proved by research on neurosciences" claimed by
psychologists/sociologists/economists is one of my favourites of the moment.

------
general_ai
Great entertainment for anyone with basic knowledge of statistics: read
medical papers. Lots of laughs to be had. Most experiments are bogus. Most
conclusions are drawn with little in the way of supporting evidence, often
without controlling for obvious confounding factors. Correlation is implied to
mean causation. Extrapolations abound, both for concentrations (i.e. if I give
this mouse a megadose of X it'll die, hence X is harmful) and between species
(mice grow tumors if I give them a ton of X, so humans will too if they
consume a tiny fraction of the amount per unit of body weight). Most of it is
basically bro science, except expressed in much longer words.

~~~
cperciva
_Extrapolations_

Technically, going from "megadose is lethal" to "smaller doses are harmful" is
an interpolation, not an extrapolation.

~~~
TeMPOraL
Only if an even smaller dose was tested too.

~~~
petertodd
Well, technically anyone with a pet mouse is doing the experiment "Does a dose
of ~0ppm of cyanide/arsenic/etc. kill mice?" :)

~~~
AstralStorm
That is called a control group. You need to actually have a formal one and big
enough too.

It has to be kept in as similar conditions as the group under treatment and
have genetically similar makeup.

Most importantly, the composition of both groups and the conditions the
experiment is ran under should be rigorously described.

------
wyager
I have no serious issue with fad-diet pundits and talk show hosts giving bad
advice based on extremely weak science. My issue is when the government does
this, and sets regulations, dietary guidelines, and school lunch rosters based
on bunk.

Changing the diets of millions of children at once should require airplane-
construction levels of confidence, at the very least. Instead the FDA and FNS
are running off low-confidence garbage and acting as if they have an
authoritative standing, playing with potentially trillions of dollars of
future utility differences spread across tens of millions of schoolchildren.

~~~
paulddraper
> Changing the diets of millions of children at once should require airplane-
> construction levels of confidence

The safe default for airplane construction is not to build it (or not fly it).

There is no "safe default" for a diet...it's not like you can stop eating. So
they'll serve their best guess of a good school lunch.

~~~
gozur88
We have thousands of years of experience in feeding children. Changing a
dietary recommendation should require iron-clad evidence.

~~~
JoeAltmaier
For most of history, children have been fed badly. Its a hyperbolic
exaggeration of the first order to claim millennia of experience.

~~~
opportune
I feed my children only sunshine and they usually stop complaining after 2-4
weeks.

------
onion2k
The news only reports change. If the advice isn't changing then it won't be in
the news. That makes it feel like everything is changing because we conviently
ignore all the advice that hasn't changed. If you look at medical advice as a
whole it hardly changes at all, so most of it never gets in the news.

Also, most people follow news organisations that are fastest instead of
following the organisations that are slower but rigourous. It doesn't matter
if the advice is wrong; it still gets more eyeballs.

------
mk827
I grew up in India surrounded by a whole bunch of general health and nutrition
advice which seems to be an aggregation of centuries of culture specifically
suited to my culture, location and genetic makeup. There's no evidence for any
of it, but it is what seems to have been learnt over the years. I have somehow
always trusted it more than these ever changing fads that the newspapers were
too eager to push at me. I know though that by the scientific yard stick these
traditions don't stand up to scrutiny but I studied enough science to
understand that these general advisory guidelines were as likely to be hocus
pocus as my grandmother's so called wisdom. Mind you this is not about western
medicine, just about food and lifestyle recommendations. #justsaying.

~~~
AstralStorm
It's applying leeches still recommended for most health conditions there?

What makes you trust one ancient knowledge over other ancient knowledge?

------
nacc
For many assertions, my quick filter is: what the _direct_ experimental design
would look like to draw such conclusions? Is it possible that it is done
somewhere?

Biology is so complex and we know so little about it, so that the normal logic
often fails on it: if A -> B, B -> C, you need to do experiments to show A ->
C. Error accumulates, other unknowns come in.

If you have to draw conclusion by logic in biology, look at the errorbars and
sample size. Then stretch the errorbars by the square root of the sample size.
Then stretch it again 3 times. If the conclusion still look obvious to you,
proceed with caution.

~~~
wfunction
I know zilch about biology or medicine but my impression is that in biology
even A->B doesn't imply A->B half the time. Like you might do a large study
and find that people get obese after consuming fat, only to later find that if
you do the same with a different group of people, that doesn't happen.
(Exaggerating with an example here, not actually claiming this particular
example is true. Just trying to illustrate my impression of what a lot of
things in the field are like.)

~~~
noobermin
that's essentially what he said.

------
empath75
Part of the problem is that properly designed medical experiments on humans
are an ethical minefield so there are compromises all over the place.

------
umberway
I would agree that the medical field is plagued with _empiricism_ which
consists of asking a naive question (rather than working from a deeper theory)
and then doing a study to 'measure' the thing in question. Third parties then
note the correlation and issue 'advice' in the form of suggestive reporting. I
would guess this puts the public off science altogether!

Perhaps the best way to look after the body will turn out to be as Aubrey de
Grey suggests: regular servicing to repair accumulated damage. But we aren't
there yet. Plus we urgently need new antibiotics.

~~~
Fomite
The medical field is very much based off one-off effect estimates, but there's
starting to be some pushback on this. I've seen it mentioned several times
that there's value to be had in theory from relatively prominent people in
epidemiology.

~~~
umberway
[http://www.goodreads.com/quotes/6894316-never-trust-an-
exper...](http://www.goodreads.com/quotes/6894316-never-trust-an-experimental-
result-until-it-has-been-confirmed)

------
jamez1
It's a failing of the industry to treat nutrition as cause and effect when the
body is clearly a complex system.

Then again, it's hard to pick a complex system that we do model properly.. the
economy, the climate, the body, etc..

~~~
chipperyman573
If humans were removed from the equation, we could accurately model the
economy and climate (to a reasonable degree). Human randomness adds too much
entropy to the system to accurately model it.

~~~
ncallaway
The climate is perfectly chaotic without human involvement.

Much the same way that the three body problem is chaotic whether there are
people involved or not.

~~~
jackmott
the climate is a lot less chaotic than weather, and aspects of it are not so
hard to model correctly. For instance the IPCC far projections for global
average temp from 1990 have been very good.

~~~
ncallaway
Apologies. You're correct.

I should have said that weather is chaotic.

------
jodrellblank
Idlewords always a good read, the history of Scurvy and Vitamin C has some
great content relating to science and diet, how difficult it is to get
conclusive evidence, and how easy it is to jump to the wrong conclusions over
and over:

[http://idlewords.com/2010/03/scott_and_scurvy.htm](http://idlewords.com/2010/03/scott_and_scurvy.htm)

including quotes / sections:

\- It has been known since antiquity that fresh foods in general, and lemons
and oranges in particular, will cure scurvy. Starting with Vasco de Gama’s
crew in 1497, sailors have repeatedly discovered the curative power of citrus
fruits, and the cure has just as frequently been forgotten or ignored by
subsequent explorers.

\- 1747, James Lind proved in one of the first controlled medical experiments
that citrus fruits were an effective cure for the disease. [..] the experiment
involved two sailors eating oranges for six days. Lind went on to propound a
completely ineffective method of preserving lemon juice (by boiling it down),
which he never thought to test.

\- Knowing that citrus fruits deferred scurvy, but not knowing why, assuming
it was to do with acidity, and switching to a cheaper British source of
'limes' instead of a foreign source of 'limes' \- and accidentally switching
from effective fruit to ineffective fruit, without noticing.

\- Knowing that citrus fruits avoided scurvy, but not knowing that copper
breaks down Vitamin C, and keeping the juice in copper containers on ship.

\- the time Pasteurized milk was found to be better for preventing bacterial
infection in infants, so rich parents switched to it. And the heating
denatured Vitamin C so their children developed scurvy. Poor children, being
breast fed, didn't get scurvy, only richer children.

\- The sickness could be fitted to so many theories of disease—imbalance in
vital humors, bad air, acidification of the blood, bacterial infection—that
despite the existence of an unambigous cure, there was always a raft of
alternative, ineffective treatments. At no point did physicians express doubt
about their theories, however ineffective.

\- Finally, that one of the simplest of diseases managed to utterly confound
us for so long, at the cost of millions of lives, even after we had stumbled
across an unequivocal cure. It makes you wonder how many incurable ailments of
the modern world—depression, autism, hypertension, obesity—will turn out to
have equally simple solutions, once we are able to see them in the correct
light. What will we be slapping our foreheads about sixty years from now,
wondering how we missed something so obvious?

And plenty of other things they thought about ptomaines, contaminated tinned
food, stuffy air, lack of light, poisons to avoid, and all without good
experiments and with plenty of grabbing a ray of hope and committing
everything based on it.

------
jklp
If you haven't already subscribed the author (Dr Aaron Carroll) runs his own
YouTube channel - Healthcare Triage
([https://www.youtube.com/user/thehealthcaretriage](https://www.youtube.com/user/thehealthcaretriage))

Highly recommended if you're interested in the space

------
mrfusion
I'm still confused about saturated fats. Can I eat butter with abandon or not?

~~~
e2e8
Here is a post about fats from the same author:
[http://theincidentaleconomist.com/wordpress/a-study-on-
fats-...](http://theincidentaleconomist.com/wordpress/a-study-on-fats-that-
doesnt-fit-the-story-line/)

Conclusion:

"Should we be eating more polyunsaturated fats? Should we be avoiding
saturated fats? The honest answer is: I don’t know. Given my review of the
evidence, I stand by my previous recommendations [1], which essentially focus
more on foods and less on nutrients. I think the state of nutrition research
in general is shockingly flawed."

[1] [http://www.nytimes.com/2015/04/21/upshot/simple-rules-for-
he...](http://www.nytimes.com/2015/04/21/upshot/simple-rules-for-healthy-
eating.html)

~~~
mikro2nd
"Eat food. Not too much. Mostly plants."

Given what the author says in the article regarding processed foods (and I'd
disclose that I agree with his summation) I have to wonder about the whole fad
for Soylent. It seems to me a technofix beloved by food haters, but some part
of me suspects that, in the fullness of time, we'll find out that it is an
incredibly bad idea.

~~~
AstralStorm
The trick is, Soylent is not new, similar things are in use as enteral feeding
in hospitals, much more expensive, rigorously designed and validated.

------
Angostura
So, Doctor - you're telling me that vaccines could well cause autism?

If you're _not_ saying that, why not? Given that "credible evidence is
nonexistent in the medical field."

~~~
dang
This crosses the line into incivility, which is the last thing we want on HN,
especially when talking with domain experts whom we're lucky to have in this
community. Please conduct yourself better than this in the future.

We detached this subthread from
[https://news.ycombinator.com/item?id=13423680](https://news.ycombinator.com/item?id=13423680)
and marked it off-topic.

~~~
Angostura
I'm sorry, but when an individual descends into hyperbole by dismissing an
entire branch of research endeavour with 'credible evidence is nonexistent in
the medical field' \- it is worth attempting to find out whether they actually
believe that there are simply no good studies ever carried out.

The 'So Doctor' was unfortunate - I was framing a response from a fictious
patent walking into his/her surgery, but the wording doesn't work and I can
see how it appears aggressive.

Nonetheless, yes when there are organisations such as
[https://www.nice.org.uk](https://www.nice.org.uk) and
[http://www.cochrane.org](http://www.cochrane.org) trying their hardest to
pull together the best evidence out there, this broad dismissal is irritating.

~~~
rscho
Ok. I never said there was no effort towards improvement. However:
[https://www.ncbi.nlm.nih.gov/pubmed/17205029](https://www.ncbi.nlm.nih.gov/pubmed/17205029)

