March 29, 2018 • 44 mins
When getting a medical diagnosis, it's important to understand the terms. Negative is good, positive is bad, false positive is great in a way, but false negative is the worst. Learn all about false positives, when your tests indicate you have a disease of some kind when you don't, and what this means in the medical community at large.
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Episode Transcript
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Speaker 1 (00:01):
Welcome to stuff you should know from how Stuff Works
dot com. Hey, and welcome to the podcast. I'm Josh Clark,
and there's Charles W. Chuck Bryant. It's just us. There's
no producer, there's no guest producer, there's no nothing, just
(00:22):
a ghost in the chair. Why is it whenever we're
in this room, just the two of us, I go
back to like elementary school or middle school and feel
like we should just start drinking whiskey or something. Isn't
that weird? Uh? Yeah, well, I guess Jerry kind of
provides like a teacher like presence, and I guess Nol
(00:44):
is kind of like a substitute teacher like presidents. So
I didn't ever have the urge to drink whiskey in
elementary school. But I can see where you're coming from.
It was eighth grade before that started from me. I
did drink to college. But I don't know. It's just
and neither one of the Jerry. No one would care.
Even it's just some weird thing about the teacher leaving
the room. After all these years, I'm still like, all right,
(01:07):
I need to act up right. My thing went more
towards paper airplanes than breaking out the pint bottle whiskey
I have in my sock. Again, I didn't even drink
until college, so of course I wasn't doing that. I
just probably started joking around. No, I know what you mean,
but today's Chuck, but hit the bottle right. Actually, today's
(01:28):
Chuck is all business. Because I hate to tell you this, buddy,
but you're doing your job right now. That's true. We
both are because this is our job to podcast. It's
funny during the the Emily and Chuck pre Oscar's Mini
Crush show, it was kind of dragging on. She's like,
this starting to feel like a job, and I was like,
this is my job. This is the job. The job
(01:52):
we we say. We talked about it like cops talk
about their jobs, good jobs. We're real, real podcasters that job.
Remember that show The Wire. Have you ever heard of it?
I'm just kidding. We've talked about it before. I remember
they called that one uh cop, real police, Yeah, real police.
I can't remember her name. Yeah, they said a lot
(02:15):
on that show. Yeah, but they mostly talked about one
officer in particular, police trying to think of Yeah, right,
there you go, So let's start real podcasting is this
one gonna be a stinker. No, it's not. Actually, it's
actually really do you know why, because it has the
(02:38):
hallmarks of a good episode, And I'm gonna I'm gonna
peel the curtain back a little bit for everybody, Chuck.
One of the hallmarks of a good episode, at least
of stuff you should know, is that there is controversy
associated with something even where there doesn't seem to be,
and that there are people who are either getting drew
(03:00):
it over, suffering, being neglected, being abused. There is some
group of people who the rest of the world aren't
really thinking of, um, who are who are suffering at
the hands of other people. And this this actually, this
episode has all that, all right, Surprisingly, I'll let you
guys guess where that stuff comes in. Alright, So we're
(03:24):
talking about false positives, and here's what that is. If
you've ever been to the doctor, I've had a medical
test done generally, well, not generally always, you will get
one of four results. Yeah, good point. You can get
a true positive. And remember, when you're getting a medical
(03:45):
test back, positive is negative. Yeah, usually means bad news.
Positive is not good. They don't say I have news,
I have good news. For you. Your results are positive,
it's a little bit of a mind trick that you
need to reform. But positive is you have this condition. Right.
It means that the the test that that searches for
(04:09):
a condition found a result. It is confirmed as yes. Right,
so that's it should say that's a true positive. Right. Yeah,
then you've got a true negative, which means you don't
have this. However, I feel like me or probably you
and most people, you say that's good news, but I
should like to get a confirmation on that. Yeah, how
(04:30):
do you know? How do you know? Doc? Then you
can get a false positive, which is what we're talking
about here, which is they say you have this condition,
like let's say you have cancer. I'm sorry to tell you,
but you don't, as it turns out later on, which
is great. False positives are kind of they should call
it the new lease on life result, right, the Dabney
(04:50):
Coleman out of time result. And then the worst of
all probably is the negative. Agreed. Man, I'm glad you
said that, because this this article just walks right past
that fact. That means results say you're fine, but it
turns out that you're not. Your your toast, so whatever
the lead and not even good avocado toast. You're bad
(05:12):
burnt toast right, exactly terrible stuff with that really cheap
sliced cheese that nobody would want to eat. What's what's
the opposite of a lease on life to result um
early death? Sudden early death out of the blue, Although
there is something to be said about that, about just
not knowing right just out of nowhere, bay up, you
(05:34):
just fall over dead. That's not necessarily the worst way
to go. Yeah, I guess I was thinking more in
the play on words of instead of a new lease
on life, something to do with renting in your landlord,
so an old and uh, we'll figure this one later
and dub it in Wait, what's it called when you
(05:55):
get kicked out of your apartment? An old eviction death? God,
we did it, chuck man. So those are if you
take a test at the doctor, those are the four
possible results you can get. What's really interesting here, and
this is something that you're going to want to remember.
And after you hear the rest of what we have
(06:16):
to say, you're really gonna want to remember this. But
when you hear something like this test that I'm about
to give you is accurate It doesn't mean that if
it comes back with a positive result that says you
have this thing. It doesn't mean there's a nine chance
that you have that. It just means that when they
say a test is accurate, that if if you do
(06:39):
have that disease, there's a chance that this test will
catch it. Okay, huge, huge difference between those two things. Okay,
that's step one. So really what this is saying is
that this test doesn't let very many false negatives get through.
And if you look at the numbers, this is how
(07:00):
that works out. If you have ten thousand people chuck,
and they take a test that's accurate. Uh and and
this is so ten thousand people and the them don't
have this and it's a ninety nine percent accurate test,
there's going to be one hundred that come back positive
(07:21):
out of ten thousand. Okay, nine of those positive results
are going to be true. One is going to be
a false negative. Okay, Okay, are going to be negative.
They're gonna come back negative. One are going to be
true negatives, but are going to actually be false positives. Right.
(07:47):
I know this is really mind bending, but if you
if you take the numbers like this, that means that
only one out of nine thousand, eight hundred and two
people had a false negative. So that's a big deal.
As you said, that's the big daddy, that's the one
you've got to really watch out for. But nine out
of a hundred are false positives, which means that this
(08:10):
accurate test has a fifty percent chance of giving you
a false positive if you come back positive. Should I
just not even have said any of that stuff now?
I think it's just funny that after ten years it's
done on me that you have to true talents. One
is explaining extremely complex things in a very easily digestible way,
(08:33):
and the other is completely confusing me with words that
come out. Well, this is very confusing stuff. I mean,
it's not just me, this is BAYSI and statistics. Basically,
the point of all of this is is that, first
of all, if you're accurate test comes back that says
you have something, it doesn't mean you have a ninety
nine chance of that you have it. Very important number one.
(08:55):
Number two, if it does say you have it, there's
a fifty chance that a test is wrong even if
it's accurate test. That's a big thing to remember that
if your doctor doesn't explain that to you, you punch him,
him or her in the arm and you say you're
not doing your job fully because I'm scared, buddy. Yeah,
(09:17):
I just got a positive test result and I'm scared
out of my mind. So if your doctor is not
going to come for you, hopefully Baysian statistics, well, and
don't listen to me, go look it up yourself, because
I'm sure someone else on the internet can explain it
better than I can. Perhaps Mr Billy Bays in his
whole statistical model. Was he a character of Melrose Place?
(09:40):
I think so. He's a pool cleaner? Um. Alright, So
with medical testing period, like you said, if your doctor
is not telling me that, with with any test that
you take, not all medical tests are created equally. Some
are really accurate, some aren't as accurate as a well
that's about say, so they could be. There's accurate as
they can be, which is to say, maybe not as
(10:02):
accurate as you would like it to be sure, but
you really need to talk to your doctor and hopefully
they're offering this up anyway, like, Hey, what's the deal
with this test? How reliable is this? Do I need
to get a second test? Because the whole thing with
false positives and false negatives and even true positives and
negatives is there's a bunch of different reasons why uh
(10:26):
follow up testing is both good and bad. Like sometimes
these procedures, like the follow up isn't like a pen prick.
Sometimes it's an actual surgical procedure that you may not
need a lot of times, and we'll get into these
more specifically, but there's expense involved. Um, a lot of
times you don't you didn't need to spend that money,
(10:48):
but you know, it's hard to say, because you should
be your own medical advocate and spend whatever money you
can to ensure that uh, the testing is is reliable.
And then there are things like the time that it
takes between these things, like all right, we'll see you.
We need to follow this up with another test, but
it's gonna take three months to get you in. And
in the meantime, in those three months, you're stressing out,
(11:11):
you're up all night, you can't sleep, your sex drive
is out the window. That sounds like a silly thing
to talk about, but it's a real thing, especially when
you're grown ups like us. Yeah, it's important, um, but
it's it's a here's a study from two thousand nine said,
granted this is a little old, but it's from the
Annals of Family Medicine, and when it came to test
(11:33):
for prostate long colorrectal and ovarian cancers, they found that
positive false positives. Uh, after four tests they did tests,
I think either four tests or fourteen test. After four tests,
you had about a thirty seven percent chance for men
(11:54):
in the chance for women for false positive. And then
the more test you got, the more that went up,
which is distressing. It is something like if you had
fourteen tests, all fourteen to the tests that they studied, um,
you had a sixty point four percent chance for men
and forty eight point eight percent chance for women of
coming back with a false positive. And again this isn't
(12:17):
just like it's yes, you have that new lease on
life on the other side, but studies have shown like these,
getting a false positive result from a test, it it
can be emotionally devastating and it can have an impact
on your finances if you're a Scrooge McDuck type who's
only moved by the idea of money, well and your
physical health because of stress. Yeah, because it's not like
(12:38):
you're not addicted demand which in the time just because
you're stress eating the whole time. So that's not good
for you. What was man? Which man? Which was a
canned sloppy joe starter. Okay, I know it's a meal,
and well it's more than a meal. A sandwich is
a sandwich, but a man which is a meal? Oh
that's right, I got it wrong. You're like, no, it's
(12:58):
more than a meal. Even it's even greater than the
ads per prophecies. Uh so the financial costs like you
were talking about Scrooge McDuck um forty. They did another
study of about a thousand people, and this was in
December of two thousand four and the issue of Cancer
(13:19):
Epidemiology bio Markers in Prevention that is a legit journal,
just by the title oh for sure, oh eight, and
then it says and and wakeboarding. More than participants had
at least one false positive. Of these people went on
to receive additional care at a cost of about a
(13:41):
thousand dollars for women and about eleven for men. So
that's not chump change. No, it's not um And a
lot of people say, well, who cares, I got insuredce, Well,
the health care spending is kind of a problem in
this country. There's apparently in two thousand five, the National
Academy of Sciences big shout out to them UM. They
(14:04):
found that there was thirty of healthcare spending was wasteful
in the United States in two thousand five, and the
idea of that gave rise to something. There's a campaign
called Choosing Wisely. Have you heard of that? Know? So
it's a campaign called Choosing Wisely. They have a site
called Choosing Wisely dot org. It's a joint effort between
(14:25):
the American Board of Internal Medicine, so it's physician based
and consumer reports, and they're basically saying, like, there are
a lot of unnecessary tests being performed out there that
are leading to these unnecessary surgeries, unnecessary expenses, unnecessary anxiety,
(14:45):
and we want to figure out what they are, and
we want to start advising people against them, or at
least advising doctors to advise their patients against them because
they might be unnecessary. And so this campaign UM has
really kind of had a big impact is we'll talk
about in a little bit. You know, the idea of
breast cancer screening has changed. The recommendations have changed from
(15:08):
what I understand from this Choosing Wisely campaign as UM
really kind of just shifted things from well, this over
abundance of caution can't be harmful to actually there are
some harms involved in an over abundance of caution. Let's
kind of UM streamline our caution and make it a
little more UM laser focused. Should we take a break? Yeah,
(15:31):
all right, we'll take a break, and I'll I'll hit
you with a stat right out of the gate when
we come back. All right, So before break, you were
(16:04):
talking about UM breast cancer and mammograms in particular, And
there was a study a few years ago in twenty
two zero about false positive mammograms and breast cancer over
diagnoses alone at four billion dollars a year billion. So
(16:27):
it's it's just such a fine line of uh, striking
the right note with preventative care and over diagnoses. Yeah,
and here's here's the problem. Like the tests, it's not
like they're not out there saving people's lives. Yeah, it's
not like the people like Dr Papa Nicolau who came
(16:50):
up with the pepsmere said, oh man, this is gonna
be like a cash register for Western medicine. That's not
what these tests were designed for. Unfortunately, they are used
in some circumstances like that, and probably more circumstances than that.
They're used again out of an over abundance of caution,
because no doctor wants to be responsible for missing something
and their patient um and and the leading to their
(17:13):
patient dying, so they're using this over abundance of caution.
The problem is that the tests aren't aren't infallible. They
do have um they do have accuracy problems, and some
tests are better than others, or another way to put it,
some tests are worse than others as far as false
positives go. And it takes the PEPs mirror in particular. UM.
(17:35):
With the PEPs mirror, it looks for pre cancerous cervical cells. Right,
three million, three million women in the United States get
a positive PEPs mirror result UM. From what I understand,
every year only three thousand of them have a deadly
cervical cancer and that of women will get a false
(17:57):
pepsmere in their lifetime. But is the thing. Four thousand
women who die in the US every year from cervical cancer,
most of them did not have a PEPs mirror or
hadn't gotten a PEPs mirror in the last five years.
So there's a really there's a there's a tough um
relationship between using the tests and and and overusing the tests.
(18:20):
And for every say, I think two thousand women who
undergo a mammogram, one woman's life is saved. Well, those
two thousand women, they didn't know whether it was gonna
be whether they were going to be the one whose
life was saved or not, so that to them or
to their doctor, it was worth it. Unfortunately, two hundred
of them will get false positives, and ten of them
(18:43):
will undergo unnecessary surgeries, painful, unnecessary surgeries to remove non
cancerous suspicious cells in their breasts. So there's this idea
where yes, we need to use these tests, and then
there's also this idea where we need to use these
tests better or come up with more accurate tests. Yeah,
(19:05):
I mean, in particular, mammograms UH and screening for colorectal
cancer are two of the big ones that can show
a lot of false positives, and they're sort of under
the microscope as to how we can correct this UH
moving forward. UM. For instance, mammograms UM correctly identifies breast
(19:26):
cancer of the time However, uh, if you're younger, if
you're a younger woman, or if you have very dense breast,
you're more likely to have a false positive. And so
because of this, over the past like even ten to
fifteen years, they've changed the recommended recommended age a few
times for who when when you should start getting these mammograms.
(19:51):
It's gone from I think in two thousand nine they
recommended between fifty and seventy four. Uh, then I think
it went down, but mean, um, I think it went
all the way down to forty. At one point, forty
was where it started, I think where it started, then
up to fifty and now I think this is the
latest as of a few years ago, the A c
(20:13):
American Cancer Society said if you are at average risk,
and this is probably how they should do it and
not just a sweeping age. But if you're an average risk,
you should start at forty five annually, but you could
begin as early as forty and I would guess that
means if it if it runs in your family, and
then after fifty five every other year, like Emily's mom
(20:38):
and my mom both went through breast cancer, so Emily
started getting mammograms. I think it maybe even at forty
because she was in the higher risk group. Yeah, and
they're no fun to go through, but she is. Uh.
I think Emily has a good head on her shoulders
as far as advocating for herself, but also um, not
(21:02):
going off the deep end. Yeah, that's simily like through
and through. Like she's not just gonna sit there and
be like, oh, whatever you say, doctor, and she's like
that actually doesn't sound quite right. She will stand up
for herself. Yea. Yeah, advocating for herself it's important. Um.
So with Mamma Graham's chuck, from what I've seen, nobody's saying, well,
this is a kind of X ray, so you don't
(21:24):
want to build up, you know, the radiation. That doesn't
seem to be the problem with overuse of mammograms. What
seems to be the problem is that they that well,
a Mamma Graham is an X ray, and the X
ray is handed off to a radiologist and they apparently
are like eight eighty four some high eighty percent effective
at finding cancerous tumors in breast. Just looking at an
(21:48):
image of a breast. This trained human being can say, yep,
there you go right there, circle it initially go follow
this up. The follow up UM is it results in
a a biopsy, usually a needle prick biopsy to remove
some of the cells. Those are examined, and if those
come back as suspicious, a doctor might say, we need
(22:10):
to get those cells out. Most of the time those
aren't actually cancer as cells, but they're still being removed surgically,
which is painful, costly, and can be a problem emotionally
to have to go through that surgical procedure to have
cells removed that you didn't need to have removed. That's
the that's the problem with with UM mammograms as far
(22:34):
as getting them frequently, and supposedly, between ages forty and fifty,
a woman has a fifty to sixty percent chance of
getting a false positive result from a mammogram. Yeah, man,
I mean a sixty chance. Yeah. And again, no one's saying, oh,
don't get mammograms. They're gonna just totally screw you up.
It's more like medical community, we need a better way
(22:55):
to to find to keep an eye on breast cancer.
I mean they're trying. I sure they are, of course
they are. In Colorectal cancer is a perfect example. UM.
It is the second leading cancer related death in the
US right now? Um was it? Say here? A hundred
thirty two thousand, seven hundred new diagnoses in two thousand fifteen.
(23:16):
And one of the big problems with colorectal cancer is
that not a lot of well, I'm saying a lot
of people, but I think about fifty of people don't
follow up on a recommendation to get a colonoscopy because
(23:37):
they don't want to get a colonoscopy. Yeah, so that's
a problem. Have you got one of those? Not yet?
You know not. I haven't either. I'm really really not
looking forward to it. And I was researching it today
and just almost fainted like three or four times while
I was reading the procedure. About the procedure, Yeah, it's hardcore, man.
There's like a finger with tube that they stick in
(24:01):
your anus, past your rectum up to your colon. The
c seesme I think it is, which is the top
of your colon, which is basically where the your rib
cage ends on your left side, that's your sesome. They
go all the way up there and it has like
a camera and a light on the end, and basically
(24:22):
what they're doing is visually inspecting the inside of your colon.
If they see something that they find suspicious, they can
put four steps through the tube and take a sample
of it and then just you know, come on back out.
Normally they'll they'll give you a sedative for this. UM.
They also give you I can't remember the name of
the drugs um, but it basically makes you forget that
(24:44):
it ever happened. Like you can prevent you from forming
memories during the procedure. But most people don't want to
go through this, even though it's extremely effective. It finds
like of um coal erectal cancer from what I understand, Yeah,
it's amazing, what like all the advances of medical science,
they're they're literally saying, like the best way is to
(25:06):
really just get on up in there and take a look.
Just jamming up there, you know, get up there. However,
they do have some because like we said about people
won't even get a colonoscopy when recommended. Uh, they have
other tests. Now they aren't as accurate, but at least
they're at least they're trying to get another test on
(25:29):
the table for people that are reticent to have the
two stuck up their butt, and some of them work.
There's this one called colon Guard from Germany. Yeah. They
they have accuracy rate of um no, no, no, this
(25:49):
one is oh well yeah, yeah, yeah, colon Guard. That's high.
Because I'm sorry, I'm miss spoke earlier. The the colonoscopy catches.
So this stuff that you just poop into a cup
and mail it in and some Porschemo tests it. Right,
that's that's really great. Well it's not not quite. It
(26:13):
showed of the cancers that a colonoscopy would uncover. Okay,
so that's not overall. Oh okay, I got it. But
it's still pretty good, right, But it has a high
high false positive rate, of which I mean if you
think a tube up your butt will make your rectum pucker,
so will a false positive of colorectal cancer. Yeah, the
(26:37):
German one, although that might be German two. But there's
another German. Uh actually this is a German study about
stool tests, and that's when you literally are just looking
at it trace amounts of blood in the stool. Well,
some do that had accuracy all over the place. That
was from which I mean, that's such a wild swing,
(26:59):
right that I don't know if I would opt for
that one of them. So one of them. Some of them,
I should say, probably most look for blood in the stool,
some some look for DNA or genetic material of cancer
in your stool, and another one looks for chemical changes
of a certain gene that's that could be present in
your stool. And by stool, of course, I mean poop
(27:20):
by the way, everybody um and they analyze them for this,
and again they're pretty good at catching the stuff, but
they're also pretty good at giving false positives. So I mean,
that's just a great the idea that we can catch
like colorectal cancers with colonoscopy, But people who need one
don't go get it because it's such an awful procedure that,
(27:40):
like you were saying at the outset, like that begs
for something new. You want to take another break, Yeah,
let's go prepare the finger with tubes. We'll talk about
drug testing right for this. Okay, all right, So we've
(28:20):
honed in on mostly medical testing up into this point.
But if anyone's ever taking a drug test, there is
always the risk of a weird false positive. You can
be a clean liver and still get a test that said, hey,
it says here that you smoked marijuana and you can
be like, dude, I don't and have never smoked marijuana,
(28:43):
and then you have to plead. Like basically every athlete
ever this test of positive for anything says I didn't
do it, man, this false positive. They're like whatever, stoner,
but it does. That's like the same thing with up
my Twitter account was hacked alright, Like really every time
some thing awful came out on your Twitter speed someone
hacked it. Yeah, but Twitter hacking does happen, and true
(29:06):
false positives and drug tests definitely happen. Yeah, it depends
on on what you've been doing. Like if you are
using a prescription medicine or even some over the counter medicines,
you can come up with the false positive on a
drug test. It says between seven and fifteen million people
a year in the United States get a false positive
(29:28):
drug test. That's a lot because think about it. When
you know, if you're applying for a job and you
go do the drug tests and you go home and
you hear that you got passed over for the job,
I don't know if they tell you that it was
because you failed your drug tests. And even if they do,
they're not going to be like, well, we want to
hear your side of the story. Mr Candidate number nine
(29:49):
twenty seven. You know they like you, just you just
lost out on a job because of a false positive.
You lost out on a sports scholarship, you lost out on,
UM don't know, getting to deliver meals on wheels, who knows,
But you're gonna miss out on something because of a
failed drug test when you didn't do anything. You've been
(30:09):
a straight air of your whole life. But again, you
did you You made the mistake of um not keeping
up with what prescription medicines can give you false positives. Yeah,
and here's the thing parents, if you drug test your kids,
I'm not weighing in on that one way or the other.
But if you drug test your kids and they return
a positive test from marijuana and they say, Mom, that's
(30:30):
because I was in the car with some people who
are getting stoned. That's how it showed up. Uh, it's
not true. I hate to break it to you, but
that is not You will not I don't think you
can ever get a false positive for a marijuana from
second hand smoke. Right. That's not your cue to burst
into tears and grab Todd and go oh Todd, I
(30:52):
knew you would never use drugs, And Todd's winking at
the camera and breaks the fourth while and winks at
the camera Ferris Bueller style. Yeah, stoked. It did kind
of remind me though, because it said here that cocaine
is one of the drugs that routinely do not come
back with a false positive or a false negative. Yeah,
it's kind of on the money. That means they have
a good test for it. Well yeah, but I kind
(31:14):
of that made me remember that old thing. I used
to hear that like whatever percentage of dollar bills has
cocaine on it, and I thought that's totally not true
and one of those things that you just here in school.
But I looked it up and apparently that is totally true. Uh.
There was a study just a few years ago in
New York City by n y U and they found
(31:35):
of dollar bills had trace amounts of cocaine. Yes, some
ridiculous amount of euros to too. Yeah, and not just cocaine,
It's like there was some morphine, heroin and meth and
lower quantities and then all manner of disgusting gross things
on on paper money, right, which apparently people were using
to roll into a tube and sticking into their nose
(31:59):
to ingest draw ugs with not were but kind of
always have. So so the idea that, um, you can
find drugs on money? Have you heard that? They're They're
like local laws around the country in the United States
that say that police can confiscate money as drug money
if they test it and it turns out that there's
(32:20):
drug residue on it. But it sounds like it's of money.
Yeah wow, yeah, not too cool. What are some of
the other things that can give you a false positive
aside from just jamming dollar bills in your nose? So
remember that Seinfeld where I think Elaine was supposed to
go on a j. Peterman trip but she got she
(32:41):
got disinvited because she turned up positive for heroin. But
it turns out that she was eating lemon poppy seed
muffins every day. That apparently is true, although this article
or how stuff Works article gets it wrong. So the
poppy seeds don't actually contain opium, but when you're harvesting
(33:02):
the seeds, opium can rub off onto the seeds and
depending from people, they were doing opium no no, no
from so like they're harvesting opium from the poppy and
then they're harvesting seeds later, and the seeds can come
in contact with opium residue from the poppy plant. And
then however, well they're processed or not processed by the
(33:23):
time you eat them, they they have they might have
a substantial amount of opium on the outside of the shell,
which will show up in a drug test. Seinfeld was
correct because I felt was correct. Apparently, ibprofen um can
come back with a positive from marijuana, barbiturates or Benny's
(33:44):
m Benny's and that was Jack Carouac's drug of choice,
one of several. Yeah, but he really, I mean I
remember him writing about the Bennies a lot. That's how
we wrote that book in like forty eight hours. He
write on like one long scrolling piece of paper. That's
what I've always heard. But last time I heard that,
(34:05):
I was like twenty years old, so I know it
looked into it since I think it's true, Well, I
think I've seen it. Jack Caroway clad us no, uh uh.
Some some OTC colden allergy medications apparently can result in
result in positive tests for like emphetamines. It's crazy. Yeah,
well you know that, like like if you're making bathtub crank.
(34:28):
You can use suda fed as like a precursor or
an ingredient in just crank. And that's why you're only
allowed to buy like one box at a time with
a driver's license. It such a seventies. Well yeah, if
you're using over the counter suda fed to make your
your meth, that's cranky. It's crank. Uh. And then tonic water. Surprisingly, um,
(34:50):
apparently quinine contains a little bit of the real quinine,
which is a drug. So here's the thing I looked
into this. I could not figure out why quinine would
result in the positive test for heroin. Here's why, Chuck,
you ready for this. I'm ready because you know gin
(35:10):
and tonics are my jam. Okay, well, just be careful
because gin or tonic water does contain sometimes like eighty
three milligrams of quinine in it, which was a malaria
drug right well back in the thirties, Supposedly heroin dealers
started adding quinnine to their heroin to combat malaria. That
(35:30):
was the urban legend. It turns out that's not the
case at all, but quinine actually interacts with heroin in
a way that kind of boosts it and it also,
more to the point, mimics heroin's bitter taste. So somebody
would taste the heroin and what they were tasting was quinine,
but they thought they had like some dynamite s gag
(35:51):
on their hands. So it was really just kind of
to take terrible junk and make it seem like it
was much better by adding quinine. Apparently this has been
going on for so many years that they that drug
tests test for quinnine because they consider that an indicator
of the presence of heroin. I think my big takeaway
(36:11):
is here, is it quinnine and not quinine? I've heard both. Okay,
that's your big takeaway. I was laying down gold. Well
here's my deal. As lately, I don't have been buying um.
I've been buying the real deal tonics. Yeah, like Feverit Tree.
I hate to use the word artisan tonics. You should,
(36:35):
but I've been buying the artisan tonics because they're delicious,
and I've really embraced bitter as a as a taste
that I can enjoy. Now Here in my late forties,
I've never liked bitter at all, but I'm kind of
have come around to it a little bit. Yeah. It
is like the definition of an acquired taste, isn't it. Yeah?
(36:56):
But now I really like it. And you know, these
these tonics that they make her like they're made from
the real Uh, what's the root the chincha? What is
it chinchilla? It's not chinchilla, chin shona? Is it chinchona?
I believe so. Yeah, And that's like the key ingredient, right, Yeah,
(37:17):
from what I understand it is the key ingredient tonic.
I'm not an artisan tonic making cinchona bark so as I. Yeah,
I don't know if that's the key ingredient or if
it's one of them. There's also like in white willow
or something in that like an ingredient, and aspirin is
also in to water. Yeah, I don't know. I enjoy
it though, And it's it's the thing is, you don't
(37:37):
use a ton of it. You just use like an
ounce and then some club soda or whatever. If you
have artisan soda water. Oh, I see what you're saying.
So you're using artisan like tonic, not with any kind
of fizz. You're using like the tonic tonic. Yes, oh wow, man,
that is that's hardcore. It's you know, it's like dark brown.
I got you, and then you pour that in. It's
(37:59):
like a couple blounces a gin an ounce of that
and then top it off with some soda water. Give
it a good shake. Man, that sounds great. It's really
good and it has a nice come over, come on over.
I think I started gin and tonic season early this year.
That's great, which is not good. No, it's great as well. Okay, yeah,
it's not good. It's great artisan tonic made from doomed goats.
(38:22):
They have some down They have a one kind downstairs
at the eighteen. Yeah, the bitterest place. Yeah, And I like,
there's okay. But then there's another one in Evandale, States
that I think. I like there's a little more so
is there like a specific tonic or just like the
general tonic that they have? Well, the one uh in Evandale,
(38:43):
States is one called dry Tonic and one called robust Tonic,
And I think the robust just has a little more
limp lime citrus. But they're they're both delicious this stuff, man,
Nice work, Chuck trying, yes, deer clear of the drug tests.
I'm pretty sure they're going to start instituting them at
stuff media any day. Now. You know, the only drug
(39:05):
test I ever had to take my entire life was
when I went through, uh the adoption process. Oh yeah,
I remember that. I never had to take one for
for work or anything. Uh, nor have I now that
you mentioned it. I think we're in the minority. You
never had to drive a Bobcat for work. I did,
but the guy I worked for couldn't have cared less.
(39:26):
Who's insured to the teeth? Before we go, Chuck, you
got anything else? You got nothing else? All right? So
before we go? I found um one test that is
just supposed to be. It just seems to me like
it's the gold standard for test. It's an HIV screen
and it's called the Enzyme linked immunos Orbit Essay or ELSA.
(39:46):
I think we talked about it in our HIV two
parter um. This is how this test is performed. So
you you get this one screen, the ELISIA screen. If
it comes back positive, a second ELISA screen is performed
if that's positive, of a separate test that uses an
entirely different technique is performed. All this is in the
(40:06):
lab before you ever hear your results. And that means
that one in the United States, one out of two
hundred and fifty thousand tests show a false positive. That
means that has a point zero zero zero zero zero
four percent chance of returning a false positive. That is
a bomb test. Yeah that's all I got. I got
(40:30):
nothing else. Go check out choosing wisely dot org. It
seems pretty interesting to me. Uh And in the meantime,
how about some listener mail. Yeah, I'm gonna call this
email from Mr Sweedman's class. All right, this is actually
from Mr Sweedman and on his class, but we're gonna
shout out his class and helps that he starts incorporating
(40:51):
this into his class. Hey, guys, love the show on
Walrus is wanted to chime in regarding reproductive isolation or
reasons why different species don't mate. I have taught biology
for several years and evolutionary biology is always my favorite unit.
Remember when we talked about reproductive isolation and yeah, what
other different types of like how that? How that would
(41:13):
manifest itself? I remember? So he says there are several
types of reproductive isolation, and geographic isolation is one of them.
And here's a little breakdown geographic isolation when species live
in different geographic reasons, sorry, regions, ecological like isolation, same region,
different habitat, Okay, okay. So so they're in the same
(41:37):
they're in the same big city, they just don't hang
out the same clubs, different neighborhoods, different neighborhoods. Behavioral behavioral.
I always have a trouble with that word isolation. One
species mating behavior won't work on another. For instance, a
peacock won't attract a chicken, right because the peacock can't
do chaw cockaw? No, what is the peacock say? Help?
(42:01):
That's right. Uh. Temporal isolation, same area, but breed at
different times, and that could be everything from the season
to literally the time of day. That's called two ships
passing in the night reproductive isolation. And that's like I
like morning sex and the other one's like, shut up,
I only like depth sex at night when I'm drunk.
(42:22):
Then there's gametic isolation. Mating can occur, but sperm and
egg won't mix. No, not you again, And he says
in this case it is usually the egg releases a
toxin that kills the sperm. Quid. That's right. Uh, And
finally has said, my student's favorite type of reproductive reproductive isolation,
(42:42):
mechanical isolation. That's when the parts don't fit, like just wait,
just hold, like, just give me a second. Wait, I
can do this and then nothing, he says, think square, peg, round, whole. Sure,
that's a really good way to put it, way better
than what I was. So there you have a guy's
all the types of reproductive isolation. Now you know, and
(43:04):
knowing is half the battle. G I, Joe, nice job.
Don't stop believing or whatever journey lyric guide your life.
That is from Mr Baird Swedman. Thank you, Mr schwed Man.
I's goot that you added at a h What is
it Swedman? It's just Swedman, but I like Mr Mr Schwedman.
I have to call him Schwedman. You know Mr Swedman
(43:27):
from PS right exactly. That's how I'm doing well. Thank
you very much, Mr Swedman. I'm sorry I got it
wrong in the first time, but Chuck said behavioral wrong,
so we're even. I could never say that right. If
you want to get in touch with us, especially if
you are one of the fine teachers instructing America's youth
or any youth of any country around the world, because
(43:48):
we think everybody's great. You can tweet to us where
s y s K podcast I'm at Josh Ouam Clark
Chuck's at Facebook dot com slash Charles W. Chuck Bryant.
He's also on Twitter at movie Crush. You can send
us all an email to Stuff Podcast at how stuff
works dot com and it's always Join us at our
home on the web stuffy sho dot com. For more
(44:14):
on this and thousands of other topics, is it how
stuff works dot com.
Welcome to stuff you should know from how Stuff Works
dot com. Hey, and welcome to the podcast. I'm Josh Clark,
and there's Charles W. Chuck Bryant. It's just us. There's
no producer, there's no guest producer, there's no nothing, just
(00:22):
a ghost in the chair. Why is it whenever we're
in this room, just the two of us, I go
back to like elementary school or middle school and feel
like we should just start drinking whiskey or something. Isn't
that weird? Uh? Yeah, well, I guess Jerry kind of
provides like a teacher like presence, and I guess Nol
(00:44):
is kind of like a substitute teacher like presidents. So
I didn't ever have the urge to drink whiskey in
elementary school. But I can see where you're coming from.
It was eighth grade before that started from me. I
did drink to college. But I don't know. It's just
and neither one of the Jerry. No one would care.
Even it's just some weird thing about the teacher leaving
the room. After all these years, I'm still like, all right,
(01:07):
I need to act up right. My thing went more
towards paper airplanes than breaking out the pint bottle whiskey
I have in my sock. Again, I didn't even drink
until college, so of course I wasn't doing that. I
just probably started joking around. No, I know what you mean,
but today's Chuck, but hit the bottle right. Actually, today's
(01:28):
Chuck is all business. Because I hate to tell you this, buddy,
but you're doing your job right now. That's true. We
both are because this is our job to podcast. It's
funny during the the Emily and Chuck pre Oscar's Mini
Crush show, it was kind of dragging on. She's like,
this starting to feel like a job, and I was like,
this is my job. This is the job. The job
(01:52):
we we say. We talked about it like cops talk
about their jobs, good jobs. We're real, real podcasters that job.
Remember that show The Wire. Have you ever heard of it?
I'm just kidding. We've talked about it before. I remember
they called that one uh cop, real police, Yeah, real police.
I can't remember her name. Yeah, they said a lot
(02:15):
on that show. Yeah, but they mostly talked about one
officer in particular, police trying to think of Yeah, right,
there you go, So let's start real podcasting is this
one gonna be a stinker. No, it's not. Actually, it's
actually really do you know why, because it has the
(02:38):
hallmarks of a good episode, And I'm gonna I'm gonna
peel the curtain back a little bit for everybody, Chuck.
One of the hallmarks of a good episode, at least
of stuff you should know, is that there is controversy
associated with something even where there doesn't seem to be,
and that there are people who are either getting drew
(03:00):
it over, suffering, being neglected, being abused. There is some
group of people who the rest of the world aren't
really thinking of, um, who are who are suffering at
the hands of other people. And this this actually, this
episode has all that, all right, Surprisingly, I'll let you
guys guess where that stuff comes in. Alright, So we're
(03:24):
talking about false positives, and here's what that is. If
you've ever been to the doctor, I've had a medical
test done generally, well, not generally always, you will get
one of four results. Yeah, good point. You can get
a true positive. And remember, when you're getting a medical
(03:45):
test back, positive is negative. Yeah, usually means bad news.
Positive is not good. They don't say I have news,
I have good news. For you. Your results are positive,
it's a little bit of a mind trick that you
need to reform. But positive is you have this condition. Right.
It means that the the test that that searches for
(04:09):
a condition found a result. It is confirmed as yes. Right,
so that's it should say that's a true positive. Right. Yeah,
then you've got a true negative, which means you don't
have this. However, I feel like me or probably you
and most people, you say that's good news, but I
should like to get a confirmation on that. Yeah, how
(04:30):
do you know? How do you know? Doc? Then you
can get a false positive, which is what we're talking
about here, which is they say you have this condition,
like let's say you have cancer. I'm sorry to tell you,
but you don't, as it turns out later on, which
is great. False positives are kind of they should call
it the new lease on life result, right, the Dabney
(04:50):
Coleman out of time result. And then the worst of
all probably is the negative. Agreed. Man, I'm glad you
said that, because this this article just walks right past
that fact. That means results say you're fine, but it
turns out that you're not. Your your toast, so whatever
the lead and not even good avocado toast. You're bad
(05:12):
burnt toast right, exactly terrible stuff with that really cheap
sliced cheese that nobody would want to eat. What's what's
the opposite of a lease on life to result um
early death? Sudden early death out of the blue, Although
there is something to be said about that, about just
not knowing right just out of nowhere, bay up, you
(05:34):
just fall over dead. That's not necessarily the worst way
to go. Yeah, I guess I was thinking more in
the play on words of instead of a new lease
on life, something to do with renting in your landlord,
so an old and uh, we'll figure this one later
and dub it in Wait, what's it called when you
(05:55):
get kicked out of your apartment? An old eviction death? God,
we did it, chuck man. So those are if you
take a test at the doctor, those are the four
possible results you can get. What's really interesting here, and
this is something that you're going to want to remember.
And after you hear the rest of what we have
(06:16):
to say, you're really gonna want to remember this. But
when you hear something like this test that I'm about
to give you is accurate It doesn't mean that if
it comes back with a positive result that says you
have this thing. It doesn't mean there's a nine chance
that you have that. It just means that when they
say a test is accurate, that if if you do
(06:39):
have that disease, there's a chance that this test will
catch it. Okay, huge, huge difference between those two things. Okay,
that's step one. So really what this is saying is
that this test doesn't let very many false negatives get through.
And if you look at the numbers, this is how
(07:00):
that works out. If you have ten thousand people chuck,
and they take a test that's accurate. Uh and and
this is so ten thousand people and the them don't
have this and it's a ninety nine percent accurate test,
there's going to be one hundred that come back positive
(07:21):
out of ten thousand. Okay, nine of those positive results
are going to be true. One is going to be
a false negative. Okay, Okay, are going to be negative.
They're gonna come back negative. One are going to be
true negatives, but are going to actually be false positives. Right.
(07:47):
I know this is really mind bending, but if you
if you take the numbers like this, that means that
only one out of nine thousand, eight hundred and two
people had a false negative. So that's a big deal.
As you said, that's the big daddy, that's the one
you've got to really watch out for. But nine out
of a hundred are false positives, which means that this
(08:10):
accurate test has a fifty percent chance of giving you
a false positive if you come back positive. Should I
just not even have said any of that stuff now?
I think it's just funny that after ten years it's
done on me that you have to true talents. One
is explaining extremely complex things in a very easily digestible way,
(08:33):
and the other is completely confusing me with words that
come out. Well, this is very confusing stuff. I mean,
it's not just me, this is BAYSI and statistics. Basically,
the point of all of this is is that, first
of all, if you're accurate test comes back that says
you have something, it doesn't mean you have a ninety
nine chance of that you have it. Very important number one.
(08:55):
Number two, if it does say you have it, there's
a fifty chance that a test is wrong even if
it's accurate test. That's a big thing to remember that
if your doctor doesn't explain that to you, you punch him,
him or her in the arm and you say you're
not doing your job fully because I'm scared, buddy. Yeah,
(09:17):
I just got a positive test result and I'm scared
out of my mind. So if your doctor is not
going to come for you, hopefully Baysian statistics, well, and
don't listen to me, go look it up yourself, because
I'm sure someone else on the internet can explain it
better than I can. Perhaps Mr Billy Bays in his
whole statistical model. Was he a character of Melrose Place?
(09:40):
I think so. He's a pool cleaner? Um. Alright, So
with medical testing period, like you said, if your doctor
is not telling me that, with with any test that
you take, not all medical tests are created equally. Some
are really accurate, some aren't as accurate as a well
that's about say, so they could be. There's accurate as
they can be, which is to say, maybe not as
(10:02):
accurate as you would like it to be sure, but
you really need to talk to your doctor and hopefully
they're offering this up anyway, like, Hey, what's the deal
with this test? How reliable is this? Do I need
to get a second test? Because the whole thing with
false positives and false negatives and even true positives and
negatives is there's a bunch of different reasons why uh
(10:26):
follow up testing is both good and bad. Like sometimes
these procedures, like the follow up isn't like a pen prick.
Sometimes it's an actual surgical procedure that you may not
need a lot of times, and we'll get into these
more specifically, but there's expense involved. Um, a lot of
times you don't you didn't need to spend that money,
(10:48):
but you know, it's hard to say, because you should
be your own medical advocate and spend whatever money you
can to ensure that uh, the testing is is reliable.
And then there are things like the time that it
takes between these things, like all right, we'll see you.
We need to follow this up with another test, but
it's gonna take three months to get you in. And
in the meantime, in those three months, you're stressing out,
(11:11):
you're up all night, you can't sleep, your sex drive
is out the window. That sounds like a silly thing
to talk about, but it's a real thing, especially when
you're grown ups like us. Yeah, it's important, um, but
it's it's a here's a study from two thousand nine said,
granted this is a little old, but it's from the
Annals of Family Medicine, and when it came to test
(11:33):
for prostate long colorrectal and ovarian cancers, they found that
positive false positives. Uh, after four tests they did tests,
I think either four tests or fourteen test. After four tests,
you had about a thirty seven percent chance for men
(11:54):
in the chance for women for false positive. And then
the more test you got, the more that went up,
which is distressing. It is something like if you had
fourteen tests, all fourteen to the tests that they studied, um,
you had a sixty point four percent chance for men
and forty eight point eight percent chance for women of
coming back with a false positive. And again this isn't
(12:17):
just like it's yes, you have that new lease on
life on the other side, but studies have shown like these,
getting a false positive result from a test, it it
can be emotionally devastating and it can have an impact
on your finances if you're a Scrooge McDuck type who's
only moved by the idea of money, well and your
physical health because of stress. Yeah, because it's not like
(12:38):
you're not addicted demand which in the time just because
you're stress eating the whole time. So that's not good
for you. What was man? Which man? Which was a
canned sloppy joe starter. Okay, I know it's a meal,
and well it's more than a meal. A sandwich is
a sandwich, but a man which is a meal? Oh
that's right, I got it wrong. You're like, no, it's
(12:58):
more than a meal. Even it's even greater than the
ads per prophecies. Uh so the financial costs like you
were talking about Scrooge McDuck um forty. They did another
study of about a thousand people, and this was in
December of two thousand four and the issue of Cancer
(13:19):
Epidemiology bio Markers in Prevention that is a legit journal,
just by the title oh for sure, oh eight, and
then it says and and wakeboarding. More than participants had
at least one false positive. Of these people went on
to receive additional care at a cost of about a
(13:41):
thousand dollars for women and about eleven for men. So
that's not chump change. No, it's not um And a
lot of people say, well, who cares, I got insuredce, Well,
the health care spending is kind of a problem in
this country. There's apparently in two thousand five, the National
Academy of Sciences big shout out to them UM. They
(14:04):
found that there was thirty of healthcare spending was wasteful
in the United States in two thousand five, and the
idea of that gave rise to something. There's a campaign
called Choosing Wisely. Have you heard of that? Know? So
it's a campaign called Choosing Wisely. They have a site
called Choosing Wisely dot org. It's a joint effort between
(14:25):
the American Board of Internal Medicine, so it's physician based
and consumer reports, and they're basically saying, like, there are
a lot of unnecessary tests being performed out there that
are leading to these unnecessary surgeries, unnecessary expenses, unnecessary anxiety,
(14:45):
and we want to figure out what they are, and
we want to start advising people against them, or at
least advising doctors to advise their patients against them because
they might be unnecessary. And so this campaign UM has
really kind of had a big impact is we'll talk
about in a little bit. You know, the idea of
breast cancer screening has changed. The recommendations have changed from
(15:08):
what I understand from this Choosing Wisely campaign as UM
really kind of just shifted things from well, this over
abundance of caution can't be harmful to actually there are
some harms involved in an over abundance of caution. Let's
kind of UM streamline our caution and make it a
little more UM laser focused. Should we take a break? Yeah,
(15:31):
all right, we'll take a break, and I'll I'll hit
you with a stat right out of the gate when
we come back. All right, So before break, you were
(16:04):
talking about UM breast cancer and mammograms in particular, And
there was a study a few years ago in twenty
two zero about false positive mammograms and breast cancer over
diagnoses alone at four billion dollars a year billion. So
(16:27):
it's it's just such a fine line of uh, striking
the right note with preventative care and over diagnoses. Yeah,
and here's here's the problem. Like the tests, it's not
like they're not out there saving people's lives. Yeah, it's
not like the people like Dr Papa Nicolau who came
(16:50):
up with the pepsmere said, oh man, this is gonna
be like a cash register for Western medicine. That's not
what these tests were designed for. Unfortunately, they are used
in some circumstances like that, and probably more circumstances than that.
They're used again out of an over abundance of caution,
because no doctor wants to be responsible for missing something
and their patient um and and the leading to their
(17:13):
patient dying, so they're using this over abundance of caution.
The problem is that the tests aren't aren't infallible. They
do have um they do have accuracy problems, and some
tests are better than others, or another way to put it,
some tests are worse than others as far as false
positives go. And it takes the PEPs mirror in particular. UM.
(17:35):
With the PEPs mirror, it looks for pre cancerous cervical cells. Right,
three million, three million women in the United States get
a positive PEPs mirror result UM. From what I understand,
every year only three thousand of them have a deadly
cervical cancer and that of women will get a false
(17:57):
pepsmere in their lifetime. But is the thing. Four thousand
women who die in the US every year from cervical cancer,
most of them did not have a PEPs mirror or
hadn't gotten a PEPs mirror in the last five years.
So there's a really there's a there's a tough um
relationship between using the tests and and and overusing the tests.
(18:20):
And for every say, I think two thousand women who
undergo a mammogram, one woman's life is saved. Well, those
two thousand women, they didn't know whether it was gonna
be whether they were going to be the one whose
life was saved or not, so that to them or
to their doctor, it was worth it. Unfortunately, two hundred
of them will get false positives, and ten of them
(18:43):
will undergo unnecessary surgeries, painful, unnecessary surgeries to remove non
cancerous suspicious cells in their breasts. So there's this idea
where yes, we need to use these tests, and then
there's also this idea where we need to use these
tests better or come up with more accurate tests. Yeah,
(19:05):
I mean, in particular, mammograms UH and screening for colorectal
cancer are two of the big ones that can show
a lot of false positives, and they're sort of under
the microscope as to how we can correct this UH
moving forward. UM. For instance, mammograms UM correctly identifies breast
(19:26):
cancer of the time However, uh, if you're younger, if
you're a younger woman, or if you have very dense breast,
you're more likely to have a false positive. And so
because of this, over the past like even ten to
fifteen years, they've changed the recommended recommended age a few
times for who when when you should start getting these mammograms.
(19:51):
It's gone from I think in two thousand nine they
recommended between fifty and seventy four. Uh, then I think
it went down, but mean, um, I think it went
all the way down to forty. At one point, forty
was where it started, I think where it started, then
up to fifty and now I think this is the
latest as of a few years ago, the A c
(20:13):
American Cancer Society said if you are at average risk,
and this is probably how they should do it and
not just a sweeping age. But if you're an average risk,
you should start at forty five annually, but you could
begin as early as forty and I would guess that
means if it if it runs in your family, and
then after fifty five every other year, like Emily's mom
(20:38):
and my mom both went through breast cancer, so Emily
started getting mammograms. I think it maybe even at forty
because she was in the higher risk group. Yeah, and
they're no fun to go through, but she is. Uh.
I think Emily has a good head on her shoulders
as far as advocating for herself, but also um, not
(21:02):
going off the deep end. Yeah, that's simily like through
and through. Like she's not just gonna sit there and
be like, oh, whatever you say, doctor, and she's like
that actually doesn't sound quite right. She will stand up
for herself. Yea. Yeah, advocating for herself it's important. Um.
So with Mamma Graham's chuck, from what I've seen, nobody's saying, well,
this is a kind of X ray, so you don't
(21:24):
want to build up, you know, the radiation. That doesn't
seem to be the problem with overuse of mammograms. What
seems to be the problem is that they that well,
a Mamma Graham is an X ray, and the X
ray is handed off to a radiologist and they apparently
are like eight eighty four some high eighty percent effective
at finding cancerous tumors in breast. Just looking at an
(21:48):
image of a breast. This trained human being can say, yep,
there you go right there, circle it initially go follow
this up. The follow up UM is it results in
a a biopsy, usually a needle prick biopsy to remove
some of the cells. Those are examined, and if those
come back as suspicious, a doctor might say, we need
(22:10):
to get those cells out. Most of the time those
aren't actually cancer as cells, but they're still being removed surgically,
which is painful, costly, and can be a problem emotionally
to have to go through that surgical procedure to have
cells removed that you didn't need to have removed. That's
the that's the problem with with UM mammograms as far
(22:34):
as getting them frequently, and supposedly, between ages forty and fifty,
a woman has a fifty to sixty percent chance of
getting a false positive result from a mammogram. Yeah, man,
I mean a sixty chance. Yeah. And again, no one's saying, oh,
don't get mammograms. They're gonna just totally screw you up.
It's more like medical community, we need a better way
(22:55):
to to find to keep an eye on breast cancer.
I mean they're trying. I sure they are, of course
they are. In Colorectal cancer is a perfect example. UM.
It is the second leading cancer related death in the
US right now? Um was it? Say here? A hundred
thirty two thousand, seven hundred new diagnoses in two thousand fifteen.
(23:16):
And one of the big problems with colorectal cancer is
that not a lot of well, I'm saying a lot
of people, but I think about fifty of people don't
follow up on a recommendation to get a colonoscopy because
(23:37):
they don't want to get a colonoscopy. Yeah, so that's
a problem. Have you got one of those? Not yet?
You know not. I haven't either. I'm really really not
looking forward to it. And I was researching it today
and just almost fainted like three or four times while
I was reading the procedure. About the procedure, Yeah, it's hardcore, man.
There's like a finger with tube that they stick in
(24:01):
your anus, past your rectum up to your colon. The
c seesme I think it is, which is the top
of your colon, which is basically where the your rib
cage ends on your left side, that's your sesome. They
go all the way up there and it has like
a camera and a light on the end, and basically
(24:22):
what they're doing is visually inspecting the inside of your colon.
If they see something that they find suspicious, they can
put four steps through the tube and take a sample
of it and then just you know, come on back out.
Normally they'll they'll give you a sedative for this. UM.
They also give you I can't remember the name of
the drugs um, but it basically makes you forget that
(24:44):
it ever happened. Like you can prevent you from forming
memories during the procedure. But most people don't want to
go through this, even though it's extremely effective. It finds
like of um coal erectal cancer from what I understand, Yeah,
it's amazing, what like all the advances of medical science,
they're they're literally saying, like the best way is to
(25:06):
really just get on up in there and take a look.
Just jamming up there, you know, get up there. However,
they do have some because like we said about people
won't even get a colonoscopy when recommended. Uh, they have
other tests. Now they aren't as accurate, but at least
they're at least they're trying to get another test on
(25:29):
the table for people that are reticent to have the
two stuck up their butt, and some of them work.
There's this one called colon Guard from Germany. Yeah. They
they have accuracy rate of um no, no, no, this
(25:49):
one is oh well yeah, yeah, yeah, colon Guard. That's high.
Because I'm sorry, I'm miss spoke earlier. The the colonoscopy catches.
So this stuff that you just poop into a cup
and mail it in and some Porschemo tests it. Right,
that's that's really great. Well it's not not quite. It
(26:13):
showed of the cancers that a colonoscopy would uncover. Okay,
so that's not overall. Oh okay, I got it. But
it's still pretty good, right, But it has a high
high false positive rate, of which I mean if you
think a tube up your butt will make your rectum pucker,
so will a false positive of colorectal cancer. Yeah, the
(26:37):
German one, although that might be German two. But there's
another German. Uh actually this is a German study about
stool tests, and that's when you literally are just looking
at it trace amounts of blood in the stool. Well,
some do that had accuracy all over the place. That
was from which I mean, that's such a wild swing,
(26:59):
right that I don't know if I would opt for
that one of them. So one of them. Some of them,
I should say, probably most look for blood in the stool,
some some look for DNA or genetic material of cancer
in your stool, and another one looks for chemical changes
of a certain gene that's that could be present in
your stool. And by stool, of course, I mean poop
(27:20):
by the way, everybody um and they analyze them for this,
and again they're pretty good at catching the stuff, but
they're also pretty good at giving false positives. So I mean,
that's just a great the idea that we can catch
like colorectal cancers with colonoscopy, But people who need one
don't go get it because it's such an awful procedure that,
(27:40):
like you were saying at the outset, like that begs
for something new. You want to take another break, Yeah,
let's go prepare the finger with tubes. We'll talk about
drug testing right for this. Okay, all right, So we've
(28:20):
honed in on mostly medical testing up into this point.
But if anyone's ever taking a drug test, there is
always the risk of a weird false positive. You can
be a clean liver and still get a test that said, hey,
it says here that you smoked marijuana and you can
be like, dude, I don't and have never smoked marijuana,
(28:43):
and then you have to plead. Like basically every athlete
ever this test of positive for anything says I didn't
do it, man, this false positive. They're like whatever, stoner,
but it does. That's like the same thing with up
my Twitter account was hacked alright, Like really every time
some thing awful came out on your Twitter speed someone
hacked it. Yeah, but Twitter hacking does happen, and true
(29:06):
false positives and drug tests definitely happen. Yeah, it depends
on on what you've been doing. Like if you are
using a prescription medicine or even some over the counter medicines,
you can come up with the false positive on a
drug test. It says between seven and fifteen million people
a year in the United States get a false positive
(29:28):
drug test. That's a lot because think about it. When
you know, if you're applying for a job and you
go do the drug tests and you go home and
you hear that you got passed over for the job,
I don't know if they tell you that it was
because you failed your drug tests. And even if they do,
they're not going to be like, well, we want to
hear your side of the story. Mr Candidate number nine
(29:49):
twenty seven. You know they like you, just you just
lost out on a job because of a false positive.
You lost out on a sports scholarship, you lost out on,
UM don't know, getting to deliver meals on wheels, who knows,
But you're gonna miss out on something because of a
failed drug test when you didn't do anything. You've been
(30:09):
a straight air of your whole life. But again, you
did you You made the mistake of um not keeping
up with what prescription medicines can give you false positives. Yeah,
and here's the thing parents, if you drug test your kids,
I'm not weighing in on that one way or the other.
But if you drug test your kids and they return
a positive test from marijuana and they say, Mom, that's
(30:30):
because I was in the car with some people who
are getting stoned. That's how it showed up. Uh, it's
not true. I hate to break it to you, but
that is not You will not I don't think you
can ever get a false positive for a marijuana from
second hand smoke. Right. That's not your cue to burst
into tears and grab Todd and go oh Todd, I
(30:52):
knew you would never use drugs, And Todd's winking at
the camera and breaks the fourth while and winks at
the camera Ferris Bueller style. Yeah, stoked. It did kind
of remind me though, because it said here that cocaine
is one of the drugs that routinely do not come
back with a false positive or a false negative. Yeah,
it's kind of on the money. That means they have
a good test for it. Well yeah, but I kind
(31:14):
of that made me remember that old thing. I used
to hear that like whatever percentage of dollar bills has
cocaine on it, and I thought that's totally not true
and one of those things that you just here in school.
But I looked it up and apparently that is totally true. Uh.
There was a study just a few years ago in
New York City by n y U and they found
(31:35):
of dollar bills had trace amounts of cocaine. Yes, some
ridiculous amount of euros to too. Yeah, and not just cocaine,
It's like there was some morphine, heroin and meth and
lower quantities and then all manner of disgusting gross things
on on paper money, right, which apparently people were using
to roll into a tube and sticking into their nose
(31:59):
to ingest draw ugs with not were but kind of
always have. So so the idea that, um, you can
find drugs on money? Have you heard that? They're They're
like local laws around the country in the United States
that say that police can confiscate money as drug money
if they test it and it turns out that there's
(32:20):
drug residue on it. But it sounds like it's of money.
Yeah wow, yeah, not too cool. What are some of
the other things that can give you a false positive
aside from just jamming dollar bills in your nose? So
remember that Seinfeld where I think Elaine was supposed to
go on a j. Peterman trip but she got she
(32:41):
got disinvited because she turned up positive for heroin. But
it turns out that she was eating lemon poppy seed
muffins every day. That apparently is true, although this article
or how stuff Works article gets it wrong. So the
poppy seeds don't actually contain opium, but when you're harvesting
(33:02):
the seeds, opium can rub off onto the seeds and
depending from people, they were doing opium no no, no
from so like they're harvesting opium from the poppy and
then they're harvesting seeds later, and the seeds can come
in contact with opium residue from the poppy plant. And
then however, well they're processed or not processed by the
(33:23):
time you eat them, they they have they might have
a substantial amount of opium on the outside of the shell,
which will show up in a drug test. Seinfeld was
correct because I felt was correct. Apparently, ibprofen um can
come back with a positive from marijuana, barbiturates or Benny's
(33:44):
m Benny's and that was Jack Carouac's drug of choice,
one of several. Yeah, but he really, I mean I
remember him writing about the Bennies a lot. That's how
we wrote that book in like forty eight hours. He
write on like one long scrolling piece of paper. That's
what I've always heard. But last time I heard that,
(34:05):
I was like twenty years old, so I know it
looked into it since I think it's true, Well, I
think I've seen it. Jack Caroway clad us no, uh uh.
Some some OTC colden allergy medications apparently can result in
result in positive tests for like emphetamines. It's crazy. Yeah,
well you know that, like like if you're making bathtub crank.
(34:28):
You can use suda fed as like a precursor or
an ingredient in just crank. And that's why you're only
allowed to buy like one box at a time with
a driver's license. It such a seventies. Well yeah, if
you're using over the counter suda fed to make your
your meth, that's cranky. It's crank. Uh. And then tonic water. Surprisingly, um,
(34:50):
apparently quinine contains a little bit of the real quinine,
which is a drug. So here's the thing I looked
into this. I could not figure out why quinine would
result in the positive test for heroin. Here's why, Chuck,
you ready for this. I'm ready because you know gin
(35:10):
and tonics are my jam. Okay, well, just be careful
because gin or tonic water does contain sometimes like eighty
three milligrams of quinine in it, which was a malaria
drug right well back in the thirties, Supposedly heroin dealers
started adding quinnine to their heroin to combat malaria. That
(35:30):
was the urban legend. It turns out that's not the
case at all, but quinine actually interacts with heroin in
a way that kind of boosts it and it also,
more to the point, mimics heroin's bitter taste. So somebody
would taste the heroin and what they were tasting was quinine,
but they thought they had like some dynamite s gag
(35:51):
on their hands. So it was really just kind of
to take terrible junk and make it seem like it
was much better by adding quinine. Apparently this has been
going on for so many years that they that drug
tests test for quinnine because they consider that an indicator
of the presence of heroin. I think my big takeaway
(36:11):
is here, is it quinnine and not quinine? I've heard both. Okay,
that's your big takeaway. I was laying down gold. Well
here's my deal. As lately, I don't have been buying um.
I've been buying the real deal tonics. Yeah, like Feverit Tree.
I hate to use the word artisan tonics. You should,
(36:35):
but I've been buying the artisan tonics because they're delicious,
and I've really embraced bitter as a as a taste
that I can enjoy. Now Here in my late forties,
I've never liked bitter at all, but I'm kind of
have come around to it a little bit. Yeah. It
is like the definition of an acquired taste, isn't it. Yeah?
(36:56):
But now I really like it. And you know, these
these tonics that they make her like they're made from
the real Uh, what's the root the chincha? What is
it chinchilla? It's not chinchilla, chin shona? Is it chinchona?
I believe so. Yeah, And that's like the key ingredient, right, Yeah,
(37:17):
from what I understand it is the key ingredient tonic.
I'm not an artisan tonic making cinchona bark so as I. Yeah,
I don't know if that's the key ingredient or if
it's one of them. There's also like in white willow
or something in that like an ingredient, and aspirin is
also in to water. Yeah, I don't know. I enjoy
it though, And it's it's the thing is, you don't
(37:37):
use a ton of it. You just use like an
ounce and then some club soda or whatever. If you
have artisan soda water. Oh, I see what you're saying.
So you're using artisan like tonic, not with any kind
of fizz. You're using like the tonic tonic. Yes, oh wow, man,
that is that's hardcore. It's you know, it's like dark brown.
I got you, and then you pour that in. It's
(37:59):
like a couple blounces a gin an ounce of that
and then top it off with some soda water. Give
it a good shake. Man, that sounds great. It's really
good and it has a nice come over, come on over.
I think I started gin and tonic season early this year.
That's great, which is not good. No, it's great as well. Okay, yeah,
it's not good. It's great artisan tonic made from doomed goats.
(38:22):
They have some down They have a one kind downstairs
at the eighteen. Yeah, the bitterest place. Yeah, And I like,
there's okay. But then there's another one in Evandale, States
that I think. I like there's a little more so
is there like a specific tonic or just like the
general tonic that they have? Well, the one uh in Evandale,
(38:43):
States is one called dry Tonic and one called robust Tonic,
And I think the robust just has a little more
limp lime citrus. But they're they're both delicious this stuff, man,
Nice work, Chuck trying, yes, deer clear of the drug tests.
I'm pretty sure they're going to start instituting them at
stuff media any day. Now. You know, the only drug
(39:05):
test I ever had to take my entire life was
when I went through, uh the adoption process. Oh yeah,
I remember that. I never had to take one for
for work or anything. Uh, nor have I now that
you mentioned it. I think we're in the minority. You
never had to drive a Bobcat for work. I did,
but the guy I worked for couldn't have cared less.
(39:26):
Who's insured to the teeth? Before we go, Chuck, you
got anything else? You got nothing else? All right? So
before we go? I found um one test that is
just supposed to be. It just seems to me like
it's the gold standard for test. It's an HIV screen
and it's called the Enzyme linked immunos Orbit Essay or ELSA.
(39:46):
I think we talked about it in our HIV two
parter um. This is how this test is performed. So
you you get this one screen, the ELISIA screen. If
it comes back positive, a second ELISA screen is performed
if that's positive, of a separate test that uses an
entirely different technique is performed. All this is in the
(40:06):
lab before you ever hear your results. And that means
that one in the United States, one out of two
hundred and fifty thousand tests show a false positive. That
means that has a point zero zero zero zero zero
four percent chance of returning a false positive. That is
a bomb test. Yeah that's all I got. I got
(40:30):
nothing else. Go check out choosing wisely dot org. It
seems pretty interesting to me. Uh And in the meantime,
how about some listener mail. Yeah, I'm gonna call this
email from Mr Sweedman's class. All right, this is actually
from Mr Sweedman and on his class, but we're gonna
shout out his class and helps that he starts incorporating
(40:51):
this into his class. Hey, guys, love the show on
Walrus is wanted to chime in regarding reproductive isolation or
reasons why different species don't mate. I have taught biology
for several years and evolutionary biology is always my favorite unit.
Remember when we talked about reproductive isolation and yeah, what
other different types of like how that? How that would
(41:13):
manifest itself? I remember? So he says there are several
types of reproductive isolation, and geographic isolation is one of them.
And here's a little breakdown geographic isolation when species live
in different geographic reasons, sorry, regions, ecological like isolation, same region,
different habitat, Okay, okay. So so they're in the same
(41:37):
they're in the same big city, they just don't hang
out the same clubs, different neighborhoods, different neighborhoods. Behavioral behavioral.
I always have a trouble with that word isolation. One
species mating behavior won't work on another. For instance, a
peacock won't attract a chicken, right because the peacock can't
do chaw cockaw? No, what is the peacock say? Help?
(42:01):
That's right. Uh. Temporal isolation, same area, but breed at
different times, and that could be everything from the season
to literally the time of day. That's called two ships
passing in the night reproductive isolation. And that's like I
like morning sex and the other one's like, shut up,
I only like depth sex at night when I'm drunk.
(42:22):
Then there's gametic isolation. Mating can occur, but sperm and
egg won't mix. No, not you again, And he says
in this case it is usually the egg releases a
toxin that kills the sperm. Quid. That's right. Uh, And
finally has said, my student's favorite type of reproductive reproductive isolation,
(42:42):
mechanical isolation. That's when the parts don't fit, like just wait,
just hold, like, just give me a second. Wait, I
can do this and then nothing, he says, think square, peg, round, whole. Sure,
that's a really good way to put it, way better
than what I was. So there you have a guy's
all the types of reproductive isolation. Now you know, and
(43:04):
knowing is half the battle. G I, Joe, nice job.
Don't stop believing or whatever journey lyric guide your life.
That is from Mr Baird Swedman. Thank you, Mr schwed Man.
I's goot that you added at a h What is
it Swedman? It's just Swedman, but I like Mr Mr Schwedman.
I have to call him Schwedman. You know Mr Swedman
(43:27):
from PS right exactly. That's how I'm doing well. Thank
you very much, Mr Swedman. I'm sorry I got it
wrong in the first time, but Chuck said behavioral wrong,
so we're even. I could never say that right. If
you want to get in touch with us, especially if
you are one of the fine teachers instructing America's youth
or any youth of any country around the world, because
(43:48):
we think everybody's great. You can tweet to us where
s y s K podcast I'm at Josh Ouam Clark
Chuck's at Facebook dot com slash Charles W. Chuck Bryant.
He's also on Twitter at movie Crush. You can send
us all an email to Stuff Podcast at how stuff
works dot com and it's always Join us at our
home on the web stuffy sho dot com. For more
(44:14):
on this and thousands of other topics, is it how
stuff works dot com.
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