0:02

A

0:02

few weeks ago, some new research made

0:05

a lot of noise. A new study

0:07

is raising some questions about colonoscopy

0:09

screenings and how much they actually reduced

0:11

deaths from colon cancer. In one

0:13

of the largest studies ever, European

0:16

researchers found colon ASKBE screenings

0:18

cut cancer risk by eighteen percent

0:21

and made no difference in death rates.

0:24

For

0:27

two decades, colonoscopy has

0:29

been a rite of passage for Americans over

0:31

fifty, though the starting age has

0:33

recently been lowered to forty five.

0:36

journalist Katie Kirk even televised

0:38

hers after her husband died

0:40

of colorectal cancer to emphasize

0:43

the importance of the procedure.

0:45

Physicians and public health experts have

0:47

long urged people to get screened

0:50

because the best available evidence suggested

0:53

not only could colonoscopy find

0:55

cancer, it could also prevent

0:57

it. Was everybody wrong?

1:01

Some doctors challenged the recent studies

1:03

findings, insisting that above all

1:05

else.

1:05

colonoscopy saves lives.

1:08

Does

1:08

it?

1:10

From

1:10

the Freakonomics Radio Network, this is

1:13

FreakonomicsMD. I'm Bob

1:15

Bugena. Today, I've got

1:17

a cold, so please forgive my voice.

1:19

It'll sound little different when I talk to

1:21

you than when you hear me in conversation with

1:24

our guests. First, Doctor

1:26

Michael Brett Howard, the lead author

1:28

of this new colonoscopy study, would

1:30

tell us what we should really take away

1:32

from his group's research on colorectal

1:35

cancer screening. So you could just say, well,

1:37

you have to close. There's no differences. It doesn't

1:39

work. I don't think it's that simple.

1:42

But first, doctor Osmotchcott will

1:44

explain why we rely so

1:46

much on colonoscopy in the US

1:48

compared to other countries and how

1:50

that can lead us astray.

1:52

Colonoscopy as effective

1:54

as it can be is heavily

1:56

heavily operator dependent.

2:11

Golent cancer is The third

2:13

most common cancer for both men and

2:16

women in the US accounts for

2:18

about a hundred and fifty thousand new cancer

2:20

cases in the US alone and

2:22

responsible for about ten percent

2:24

of all cancer related

2:25

deaths. So it truly is

2:27

a big It's common and it's

2:29

lethal.

2:30

Doctor Osmotchcott is a gastroenterologist

2:33

and a professor at New York University

2:35

School of Medicine. How I got into gastroenterology

2:38

was I wanted to do

2:40

something public health related and

2:43

I thought what are some of the large

2:45

public health questions that

2:47

we have some good evidence for, but

2:49

there's a lot of missing pieces where

2:51

we could truly make a big difference. has

2:54

tried to make a difference by focusing

2:56

on colorectal cancer screening. She's

2:59

published nearly two hundred articles on

3:01

this topic and other related ones.

3:03

And she was the lead author of the current

3:05

version of the College of

3:07

Gastroenterology's colorectal cancer

3:10

screening guidelines. In

3:11

writing guidelines, it's very

3:14

important to look at the evidence

3:16

We start with very specific

3:19

questions. For instance, one

3:21

of the questions might be at what

3:23

age should we start screening? When

3:25

does the benefit start to accrue?

3:27

A second question might be which modality

3:29

should we be using? A

3:31

third one might be how often we

3:33

should be screening and

3:35

what benefit can we expect. The

3:38

idea is then you take all the

3:40

evidence and kind of

3:42

weigh it to answer your questions and

3:45

come up with a recommendation. The

3:47

new guidelines, the ones Ospuka authored,

3:49

say that most people between forty

3:52

five and seventy five years old, should

3:54

get checked for colorectal cancer with

3:56

a colonoscopy every ten

3:58

years, or a stool sample

4:00

analysis once a year.

4:05

There's a good reason colorectal cancer

4:07

screening is so strongly recommended.

4:09

A

4:10

lot of colon cancers arise

4:12

in precursor lesions called polyps.

4:15

So the whole idea is

4:17

essentially to one, find cancers

4:19

at early stages before people are

4:21

symptomatic. Because when detected

4:23

at early stages, the prognosis

4:26

is excellent. In fact, it's one of the

4:28

cancers where we can actually use

4:30

the word cure. People can have a normal

4:32

life expectancy. if the cancer

4:34

is found and resected early.

4:35

And the second goal

4:37

is to detect these precursor lesions

4:40

so that by removing them,

4:42

we could derail that cancer. So we

4:44

can actually talk about cancer prevention in

4:47

that context. The

4:48

kind of screening asthma describes where

4:51

precancerous polyps are definitely

4:53

found and removed is colonoscopy.

4:55

She says colorectal cancer

4:58

stands alone across all of

5:00

oncology in terms of how precisely

5:02

we can look for it. Colon cancer

5:04

is unique compared

5:05

to other cancers where we can actually

5:08

detect it in these phenoplastic conditions.

5:11

that makes it very different from other

5:13

cancer where we actually look for the cancer

5:15

itself. So in that regard, it's

5:17

one of the more optimistic cancers

5:19

to screen for. Colonoscopy

5:22

has been recommended to screen

5:24

for colorectal cancer since

5:26

the mid nineteen nineties. Uptake

5:28

struggled initially and two thousand,

5:31

only around twenty percent of adults

5:33

over age fifty, then the

5:35

recommended starting age, said they'd

5:37

undergone the procedure. But by

5:39

twenty twenty, that number was

5:41

closer to seventy percent Despite

5:43

its popularity among gastroenterologists, and

5:46

its perceived value in terms of

5:48

finding and even preventing cancer.

5:50

It turns out there are still a lot

5:52

of remaining questions about

5:54

colonoscopy. Starting with

5:56

how beneficial is it compared to

5:58

other less invasive

5:59

screening methods like

6:01

say the fecal immunochemical test

6:04

or fit, which analyzes a

6:06

stool sample.

6:08

That is a million dollar question because

6:10

we don't know the answer. the two

6:12

modalities have never been compared

6:14

head to head in what we consider

6:17

a randomized clinical trial Having

6:19

said that, there are two trials

6:22

ongoing, and one of them

6:24

is actually in the US. I happen to

6:26

be a part of it. It's all across the

6:28

Veterans Affairs hospitals across

6:30

the country. We've enrolled fifty

6:32

thousand veterans and

6:35

randomized them to yearly

6:37

fit or the stool test versus

6:40

a colonoscopy every ten years.

6:42

And as you know, these studies take

6:44

a long time to get

6:45

done, And then the

6:47

outcome is going to be

6:49

risk of dying from colon cancer,

6:51

and we're looking to see if, say,

6:53

colon loss reduces

6:55

it more than fit screening. We

6:57

have to wait ten years before the results

6:59

are available. The last patient was

7:01

recruited in twenty seventeen. So

7:04

in about five years, we'll hopefully

7:06

have some results of which test

7:08

is best. So

7:09

you've been involved in devising guidelines

7:12

for colorectal cancer screening? What's

7:14

the evidence base for them?

7:16

Are we talking about randomized controlled trials?

7:18

Are we talking about observational studies? what

7:21

we look for is randomized controlled

7:23

clinical

7:23

trials because those are

7:25

considered gold standard of research

7:28

studies And in the realm of colon cancer

7:30

screening, fortunately, there have been

7:32

several since the nineteen

7:34

seventies, the largest being

7:37

one in the U. S. that I work with closely

7:39

called the Minnesota fecal alkyl blood trial,

7:41

which truly put screening on the map.

7:44

And then there have been trials

7:46

in Europe with stool testing

7:48

because it was the original

7:50

and the first modality. a

7:52

lot of evidence has gathered

7:54

around stool testing.

7:56

How do guidelines for colon cancer

7:58

screening differ between

7:59

the US and Europe?

8:01

The US tends to be an outlier for

8:04

pretty much the entire world

8:06

in that we use colonoscopy preferentially

8:09

as our colon cancer screening modality.

8:13

There are about fifteen million

8:15

colonoscopies done in the U. S. every

8:17

year everywhere else

8:19

Europe, Canada and other

8:22

places that have organized screening programs

8:24

such as Australia, parts of South

8:26

America, the predominant colon

8:29

cancer testing modality is

8:31

the stool test or the newer

8:33

version of that called fit. And

8:36

only because it's readily available,

8:38

it's affordable, it has great

8:40

evidence behind it, and it lends

8:42

itself nicely to programmatic

8:44

screening. So in Europe,

8:46

the predominant modality is the

8:49

fecal canal blood, and they actually do

8:51

it every other year. whereas in

8:53

the US,

8:54

our recommendations are every year.

8:56

And why is it that we rely more heavily on

8:58

colonoscopy in the US compared to

9:00

other countries? we're

9:01

a resource, wealth nation, and

9:04

we like to use the best and

9:06

the strongest resources we

9:08

have. And in two

9:10

thousand one, Medicare agreed to

9:12

pay for colonoscopy as a screening

9:14

tool, and truly that's

9:16

when the use soared.

9:18

Is

9:18

there variation in the

9:20

quality of colonoscopies or

9:23

in the people who perform them?

9:25

And useful for telling us something about whether

9:27

or not the identification and

9:30

removal of polyps may have

9:32

a causal effect on

9:33

outcomes. Yes. And that's a

9:36

very, very crucial point. So colonoscopy

9:38

as effective as it can

9:40

be is heavily, heavily

9:42

operator dependent. And as a

9:44

result, about twenty years

9:46

ago, we developed a set of quality

9:49

indicators for colonoscopy. One

9:51

of those indicators is, for

9:53

instance, completion of the colonoscopy

9:55

So we've set a bar that the completion rate

9:57

for screening colonoscopy needs to be

9:59

ninety five percent or higher for

10:02

an endoscopist. Another bar

10:04

is the number of precancerous

10:06

polyps detected by an

10:08

endoscopist needs to be

10:10

at the minimum. twenty five percent

10:12

or more. So those are all indicators

10:14

that tell us if the

10:17

exam was able to

10:19

detect the kinds of things that we want

10:21

to use the exam for.

10:23

Prior to the last month, what was the

10:25

evidence based for the

10:27

benefits of colonoscopy? there

10:29

was great observational data

10:31

from pretty large studies

10:33

that suggested the benefit

10:35

of screening

10:36

using colonoscopy

10:38

could reduce cancer

10:41

incidents by about eighty five

10:43

percent and the risk

10:45

of

10:45

dying from colon cancer by somewhere

10:47

between

10:47

sixty percent to eighty percent But

10:50

as, you know, observational studies

10:53

inherently have design issues,

10:56

and they have a lot of biases because

10:58

the comparison groups aren't

11:01

balanced. So therefore, some

11:03

of the results you're getting with the group

11:05

undergoing colonoscopy, maybe

11:07

not just the colonoscopy, but other

11:09

factors that make them healthier

11:12

or less like you develop cancer or

11:14

die from it. And the field

11:16

has been looking for randomized

11:18

controlled trial evidence on

11:20

colonoscopy.

11:23

And we've been waiting for a trial on

11:25

colonoscopy and asking for

11:27

one and our wish was answered.

11:29

and it's one of those be careful what you ask

11:31

or because you may or may

11:33

not wanna know what it says. What

11:35

does it say? After the break,

11:38

we'll talk with the lead author of this long

11:40

wish for randomized control

11:42

trial on colonoscopy that

11:44

has stirred strong emotions on

11:46

both sides of the debate. People

11:49

start doing things because they've are

11:51

convinced for some reason

11:53

with limited data that this is the right

11:55

thing to do. I'm about Pugena,

11:57

and this is freaking Abbott's MD.

12:03

Preeconomic

12:07

MD is sponsored by indeed

12:09

ambitious hiring goals for the last quarter

12:11

of twenty twenty two with

12:13

powerful hiring partner, big goals are

12:15

no big deal. You need indeed.

12:18

Indeed. Indeed is the hiring platform

12:20

where you can attract interview,

12:22

and hire all in one place.

12:25

Don't spend hours on

12:27

multiple job sites looking for

12:29

candidates with the right skills, when

12:31

you can do it all with indeed.

12:33

Find top talent fast with indeed

12:35

suite of powerful hiring tools,

12:37

like indeed instant match,

12:39

assessments, and virtual interviews.

12:41

Kate waiting,

12:42

Indeed's US data shows

12:45

over eighty percent of Indeed employers,

12:48

find quality candidates whose

12:50

resume on Indeed matches their job

12:52

description the moment they

12:54

sponsor a job. In

12:55

Star App can shine before the

12:57

interview with over one hundred and

12:59

thirty five, indeed, rated

13:01

assessment tests they can take.

13:03

From cooking, to coding,

13:06

joined over three million businesses

13:08

worldwide using indeed

13:10

to hire great talent

13:12

fast. Start hiring now with a

13:14

seventy five dollars sponsored job

13:16

credit to sponsor your job

13:18

post at indeed dot com slash

13:20

economics. offer good for a

13:22

limited time. Claim your

13:24

seventy five dollar credit now at

13:26

indeed dot com slash economics.

13:29

Indeed

13:29

dot com com slash beeconomics.

13:32

Terms and conditions apply. Need

13:34

to hire. You need indeed.

13:39

Take

13:40

charge of your purchases with a cash

13:42

back rewards credit card from Pathway's

13:44

Financial Credit Union. Make purchases

13:46

anywhere anytime. and

13:48

get one point five percent cash back

13:50

for each dollar you spend. That's

13:52

right. One

13:53

point five percent cash back for each

13:55

dollar you spend. Visit pathway

13:57

c

13:57

u dot com. That's pathway c u

13:59

dot

13:59

com to find out more about the

14:02

cashback

14:02

rewards credit card from Pathways. Pathway's

14:04

Financial Credit Union. Your true

14:06

financial

14:06

partner, member NCA, Equal

14:09

Housing Lender.

14:11

My

14:15

name is Michael Brett Hauraur.

14:17

I am a professor of medicine

14:19

here at University of Oslo and

14:21

the Oslo University Hospital where

14:23

I am also a gastroenterologist. Doctor

14:26

Michael Brett Howard, lives in Norway,

14:28

which is different from the US in

14:30

a lot of ways. But for the

14:33

purposes of this discussion, there's

14:35

one

14:35

difference that stands out. Most

14:37

countries here in Europe do not

14:40

actively recommend colonoscopy as

14:42

a primary screening test for the general

14:44

population because people think it's too

14:46

invasive It's too costly

14:49

and there was a lack of

14:51

randomized trials that can

14:53

quantify the

14:54

benefit of that screening test colonoscopy until

14:57

we published our study. That

14:59

study is titled, Effect of

15:01

colonoscopy screening, on

15:03

risks of colorectal cancer and

15:05

related death, and it was published in

15:07

October in the New England Journal

15:09

of Medicine. It's findings

15:11

rattle gastroenterology, especially

15:13

in the US because they suggest

15:15

colonoscopy may not be

15:17

as effective as previously

15:19

believed when it comes to detecting

15:21

colorectal cancers and

15:23

also reducing deaths from the disease.

15:26

On its face, This one's countered

15:28

to what previous research has shown.

15:31

Is this study a game changer?

15:34

As Osmo Shotcut told us earlier,

15:36

To do a proper randomized controlled

15:39

trial of colorectal cancer screening

15:41

methods, you'd need a lot of time.

15:43

Which Michael and his team had?

15:46

We

15:46

started to plan this trial fifteen

15:48

years ago. We had our first meeting in

15:50

two thousand five. And

15:52

already then, we

15:55

had a strong interest in

15:57

finding out what the benefits and

15:59

the harms are

15:59

of colonoscopy screening for

16:02

the general population to be used as

16:04

a collateral cancer screening tool. So we

16:06

wanted to find out because we thought,

16:08

well, we would like to know with the

16:10

best methodology available, which

16:12

are randomized trials. how large

16:14

is the benefit as compared to the

16:16

harms? And then we set

16:18

out to plan this trial, which happened to

16:20

be very, very large and needed

16:22

to run for a long, long time.

16:24

Tell me about the study design, where the

16:26

patients were, how they were

16:28

recruited, what was done,

16:30

all that. The

16:30

research question we ask is,

16:33

what are the benefits of

16:35

introducing a screening program for

16:37

a general population of people

16:39

around sixty years of age, which is usually

16:41

a good screening age for colorectal cancer.

16:44

What is the effect of such a

16:46

population screening program? we looked

16:48

for cities and

16:50

regions in Europe where

16:52

such screening was not yet introduced

16:54

because we wanted a control group

16:56

of people who did not get that

16:58

test. And we found four

17:00

regions in Europe, one region

17:02

in Norway and the south of the country and

17:04

one region in Sweden in the middle of Sweden.

17:07

One region in Poland and

17:09

two regions in the Netherlands. We

17:11

set up colonoscopy centers.

17:13

And we built an infrastructure

17:15

and then we randomized

17:18

all the people to either

17:20

get an offer for a colonoscopy

17:22

or no offer at all. And

17:24

there were about ninety five thousand

17:26

people living in these cities where we

17:28

were with the trial. and

17:30

one third got an invitation for a colonoscopy and

17:33

the other two thirds did not get an

17:35

invitation. And then, of

17:36

course, We did the examinations,

17:38

which took us about four years.

17:40

And then we

17:41

followed everybody in both groups, the people

17:43

who got the invitation and the people who

17:45

didn't get an patient followed them for

17:47

ten years with regard to the risk

17:49

of getting colorectal cancer and the risk

17:51

of dying from colorectal cancer.

17:53

And

17:53

what was the standard of care for patients in

17:56

those regions before the trial was

17:58

conducted? The

17:59

standard of

17:59

care was no screening which

18:02

was important for us. There was no

18:04

screening program set up by the

18:06

government or the local authorities, and

18:08

there were no private endoscopy

18:10

clinics. as you would have in the US. This

18:12

is different. This is Europe. So it's a public

18:14

healthcare system, and so there will be no

18:17

availability for people in the control group

18:19

to get

18:19

screening. Obviously, there were services if

18:21

they were referred by their JP

18:24

for some complaints that was available

18:26

but not colonoscopy is for screening in the

18:28

usual care group. So

18:29

in the usual care group, no access

18:31

to colonoscopy really unless they had

18:33

symptoms like bleeding from below or

18:35

something like Correct. Were they doing stool testing

18:37

or any other form of non invasive

18:40

testing? No. No.

18:41

No testing at all. No.

18:43

Nothing. many

18:44

people got colonoscopies in the

18:47

invitation group. The participation

18:48

rate of the people who got an invitation

18:50

was different in the four different countries.

18:52

So here in Norway, where I'm sitting right now,

18:54

sixty percent, six zero of

18:56

all the people who we invited

18:59

said yes, and underwent a colonoscopy, which

19:01

is a very high number. In the

19:03

other countries, it was lower. In Poland, it

19:05

was thirty three percent of

19:08

the people in Sweden, it was about forty two percent

19:10

and in the Netherlands, which is not part of

19:12

the current paper. It was down to

19:15

twenty two. So

19:15

between twenty two and sixty percent of the

19:17

people showed up for their colonoscopy. And

19:20

then what did you find?

19:21

We did all these

19:23

colonoscopies, about thirteen thousand

19:26

colonoscopies. We removed a lot of

19:28

polyps. We found some cancers, obviously,

19:30

some early cancers. over

19:32

here, we have all these registries

19:34

that follow people over time. So

19:36

it was easy for us to check

19:39

if people got cancer or if

19:41

they died of cancer. We found

19:43

that after ten years, the

19:45

people in the Sweden group the

19:47

folks who did not get an offer for screening

19:49

one point two two percent got colorectal

19:51

cancer as

19:52

compared to zero point nine eight percent

19:54

in the screening group, which is

19:56

a relative risk reduction of eighteen

19:58

percent, one eight

19:59

percent. That's the main outcome. So

20:03

that of course includes all the people

20:05

who were randomized to screening

20:07

but did not show up.

20:09

We also did so called pair

20:11

protocol analysis, where you only look at

20:13

the people basically got the

20:15

colonoscopy as compared to the people in the

20:17

control group. Now that is a

20:19

tricky analysis to do because

20:21

you always have election bias of the people

20:23

who show up versus the control

20:25

group. There is more uncertainty to these

20:27

estimates. However, the results were,

20:29

of course, more favorable for screening.

20:31

So for risk of colorectal cancer,

20:33

the effect was thirty one

20:35

percent reduction. Then we look at

20:37

death of colorectal cancer there, the risk

20:40

of all dying of colic cancer

20:42

was low. Even in the

20:44

control group, it was not higher

20:46

than zero point three percent,

20:48

which is

20:48

a very low risk. and the

20:50

reduction in the screening group was not

20:53

different and it

20:54

was zero point one five.

20:57

percent in

20:57

the per protocol analysis, which is

20:59

a fifty percent five-zero decrease,

21:02

but all on very low levels. The

21:04

risk of dying from molecules, it was

21:06

very low. in both groups.

21:08

And then what did you find for the

21:10

overall or all cause mortality?

21:12

The all cause mortality was not

21:14

different between the groups. About eleven percent

21:17

of people died of any cause

21:19

in both groups, so there

21:21

was no difference.

21:23

So how would you

21:24

then put together the findings? You

21:27

found an eighteen percent reduction

21:29

in colorectal cancer for

21:32

those people who invited, but you didn't

21:34

find a statistically significant reduction

21:36

in colon cancer mortality for

21:38

that group. What I would say for colon cancer

21:40

risk is that the real effect

21:42

is somewhere between eighteen percent and

21:44

thirty one percent risk reduction. And

21:47

then, I think it's very important to talk about the

21:49

absolute risks and the absolute risk

21:51

reductions. But I want to know, okay,

21:53

should I do this? I would like

21:55

to know, so what is my risk to start

21:57

with? What is my risk of getting this

22:00

disease? if I buy a car, for

22:02

example, when I walk into the shop

22:04

and the car dealer says, hey, you can buy this car

22:06

for fifty percent off, I would still like

22:08

to know the price of the car.

22:10

Right? I

22:10

don't buy the car just with that piece

22:12

of information that it's fifty percent reduced.

22:15

So I think we should start at saying, well,

22:17

look, the risk

22:18

of getting

22:19

this disease over ten years

22:21

is one point two percent. If you find

22:23

this risk interesting enough to do something about

22:25

it, if you go to colonoscopy, you can probably

22:27

reduce it to let's say, zero point

22:30

eight or zero point nine, somewhere around

22:32

there. And that

22:32

I think is the information we need to give

22:34

to patients or to people. conscious decision

22:37

about if they want to do this

22:39

or not. It's a hallmark of a

22:41

clinical study when I see

22:44

economists tweeting about a

22:46

study. And one of

22:48

the points that I saw a lot of my

22:50

colleagues making that,

22:52

so forty two percent of those people

22:54

ended up getting a colonoscopy. If

22:56

you look at that group on average and you compare

22:58

it to the usual care group on average,

23:01

and you don't find

23:03

a statistically significant reduction

23:05

in colon cancer mortality

23:08

is it because the intervention, in this

23:10

case, the colonoscopy wasn't effective,

23:12

or because only forty two

23:14

percent of people in the group got it.

23:16

And in economics, the way we deal with

23:18

that is we view that randomization as

23:21

an instrument or an instrumental

23:23

variable. It's not perfect. But you

23:26

basically are randomizing people to a higher

23:28

probability of getting the

23:30

treatment. And if you do that,

23:32

the quote unquote effect of

23:34

colonoscopy screening is

23:36

actually quite large. I

23:37

understand that economists think

23:39

mostly about death mortality, and we

23:41

have no difference there. So you could just say,

23:43

well, except to close, there's no differences, doesn't

23:46

work. I don't think it's that

23:48

simple. Here in this study,

23:50

The most interesting endpoint I think

23:52

is incidence. So the risk

23:54

of disease. And why do I think that? Where?

23:56

Two reasons. Number one, I

23:59

think it may be a little early to

24:01

see the full effect of

24:03

colonoscopy on death because it takes time from

24:05

people getting the disease until

24:07

dying from it. everybody thought when we designed

24:09

the trial that ten years would be enough,

24:11

we were probably wrong, not just

24:13

we making the study, but everybody in the

24:15

field, it probably takes longer. we

24:17

will see that because we will follow these

24:19

people longer. The other argument, however, is

24:21

that colonoscopy screening

24:23

is intended to

24:26

prevent colorectal cancer.

24:28

So

24:28

it's intended to reduce the risk

24:30

of getting the disease.

24:33

Therefore,

24:33

the death endpoint is only a logical

24:36

consequence of reducing the

24:38

incidents. So

24:38

incidence is for me the

24:40

more interesting endpoint for this

24:43

study at this time with this

24:45

screening instrument. I would guess that if you follow these patients over

24:47

five years or ten years, you might

24:49

actually find in that case that

24:51

there is a statistically significant

24:54

reduction in death from colorectal

24:56

cancer. And I'm curious, what's your

24:58

prediction? My

24:58

prediction also would be for colorectal cancer

25:01

death that the effect will

25:03

get larger. Until a certain point in time,

25:05

I don't know where that time point is. If it's twelve

25:07

years or fifteen years or twenty years, nobody

25:09

knows. But my guess would

25:11

be that We

25:12

may see one in two years time,

25:14

one in five years time. That will be

25:16

my prediction, although I'm far

25:19

from certain. And how large that will be? I have

25:21

no idea. What has been the

25:23

feedback

25:23

that you've gotten about the work?

25:25

Like, what are people saying? And how would you

25:27

respond? There

25:28

were some heated discussions the first days after

25:30

the publication, especially in the

25:32

United States, but things have calmed down and we

25:34

have had some nice conversations. What

25:37

everybody says and I certainly appreciate is

25:40

that this is a good

25:42

study and

25:43

we did it well and it was well designed and

25:46

executed which we like

25:48

obviously because we put a lot of

25:50

thinking and emphasis into

25:52

that and that it moves the

25:54

field forward because this is the first randomized trial

25:56

with this screening tool. I think

25:58

in the GI

25:59

community, there was disappointment. was disappointment

26:02

Because

26:03

especially in the US, everybody

26:06

thought at least in the field that

26:08

colonoscopy would have a

26:10

far higher benefit.

26:12

People

26:12

start doing things because they are

26:14

convinced for some reason with

26:17

limited data that this is the right thing

26:19

to do. The

26:21

study

26:22

was what we have been

26:24

waiting for and asking for

26:26

the biggest criticism about colonoscopy

26:29

screening is that we did not

26:31

have randomized clinical trials

26:34

showing the benefit or how

26:36

effective it was. Dr. Asma Shahcott

26:38

again. Observation studies are

26:40

always optimistic and more

26:42

rosy than real life. And we've

26:44

seen this time and time again. So

26:46

that's why we do randomized trials. We

26:48

do expect the differences from

26:51

observational studies to shrink, but nobody

26:53

quite expected it to be as low

26:55

as twenty percent

26:57

The lack of reduction

26:59

in colon cancer mortality, I think,

27:01

is

27:01

somewhat premature

27:03

and

27:03

perhaps shouldn't

27:06

have been included in the main study

27:08

because for colon

27:10

cancer mortality, the study is growsly

27:13

underpowered. So just

27:15

because we don't see a difference doesn't mean

27:17

there isn't one, but

27:19

that's lost

27:19

when you read the results.

27:21

Do you think people are going

27:24

to shun colonoscopy now or

27:26

could it even have, like, the opposite effect because

27:28

of all the attention they got? So

27:29

there was a large

27:32

public health outcry and also from the

27:34

medical community. What I'm seeing

27:36

is exactly what you alluded to

27:38

is such a strong

27:40

reaction that it might put screening

27:42

on the forefront of people's minds

27:44

and invoke a discussion

27:46

with their providers, give them that extra

27:49

nudge to think about it and then perhaps

27:51

even schedule it. So we might

27:53

see some unanticipated benefits

27:55

of this. And how

27:56

would doctor Michael Brett Hauer

27:59

advise his

27:59

patients, I would start

28:02

with explaining

28:03

them their risk. And

28:06

they're very good calculators online where

28:08

you can actually calculate your risk

28:10

of getting colorectal cancer when they would

28:12

come up with the risk of, let's say, one

28:14

percent over the next ten years. If

28:17

the same, tell me what I can do and how much

28:19

I can reduce, then I would say, okay, you can go

28:21

from one percent to let's say,

28:23

a zero point eight percent which is a twenty percent

28:25

risk reduction if you come to me next week in

28:27

the office and we do a colonoscopy. And

28:29

then I will explain to them,

28:31

the harms they need to take into

28:34

consideration, so perforation and

28:36

bleeding. And then finally, I would explain

28:38

to them what a colonoscopy entails.

28:40

all the things that are involved with it.

28:42

And then I think at the end, I will

28:44

tell them now you make your decision.

28:47

And some people would say yes, and some

28:49

people would say no. And

28:50

that is really what is called

28:53

shared decision making between a

28:55

doctor and patient. They need to understand the harms and the

28:57

burdens, and then they need to make a decision. And

28:59

that's not my decision. If that's

29:01

theirs.

29:03

So what happened when it was

29:05

his decision?

29:06

I had a colonoscopy. I

29:09

thought for me personally

29:11

it was a

29:11

deal that I was comfortable with with the

29:13

numbers that we just talked about, it was

29:16

negative. So if if I'm gonna do another one in

29:18

ten years, I'm not sure I will look

29:20

up the numbers

29:21

then and decide. As

29:24

doctor Michael Brett Howard said,

29:26

once you start doing something like

29:28

colonoscopy based on limited

29:30

data, it can be hard to slow

29:32

that momentum. Colonoscopy is

29:34

pretty safe overall, but it

29:36

does come with risks. both

29:38

from the test itself and from the anesthesia.

29:41

There's also the preparation which can

29:43

be unpleasant. We should hone

29:45

invasive tests like colonoscopies

29:48

to the same standard we hold drugs.

29:51

Randomized controlled trials. Studies

29:53

like Michaels and the research

29:56

Ospuma is doing, bring us

29:58

closer. For that, we owe them

29:59

and their colleagues a dead of

30:02

gratitude. That's it for

30:04

today's show. I'd like to thank my guests, Ospo

30:07

Shawcutt and Michael Brett Howard. And

30:09

here's an idea for you based on my conversations

30:11

with them. If you wanna study

30:13

the effectiveness of this chronoscopy, you

30:16

need randomization, either in a

30:18

trial like Michael did or

30:20

natural randomization, like we talk

30:22

about all the time on this

30:24

show. So what about this? We

30:26

know doctors are affected when their patients

30:28

have a bad outcome. In

30:30

reaction, they might change how they

30:32

practice. When a patient is diagnosed with

30:35

colon cancer, their physician

30:37

might start encouraging colon

30:39

cancer screening more often

30:41

to other patients. of the saliance

30:43

of that recent diagnosis. You

30:46

might then see higher

30:48

colonoscopy rates in these

30:50

compared to eligible patients the doctors

30:52

saw before the colon cancer

30:55

case. If that happens, you'd have a

30:57

natural experiment to

30:59

study if that greater screening led

31:01

to lower cancer related mortality.

31:03

You'd need lots of data over lots

31:05

of years, but it's doable.

31:08

what ideas do you have? Did you hear about the colonoscopy

31:11

study in the news? Did it change

31:13

the way you thought about screening?

31:15

Email me your thoughts because I'd love to hear them.

31:17

I'm at boppu at freakonomix

31:19

dot com. That's BAPU

31:22

at freakonomix dot

31:24

com. In speaking of research,

31:26

we know that people typically take

31:28

advice on which podcasts to

31:30

listen to based on recommendations from

31:33

people they know and trust.

31:35

So go find someone who knows

31:37

you and trust you and tell them to

31:39

subscribe to FreakonomicsMD. coming

31:42

up next week. We had been caught flat footed.

31:45

We had missed a window of opportunity to

31:47

really get this virus under control. If

31:49

that voice

31:49

sounds familiar, it's probably because you've

31:52

heard doctor Ashishja before.

31:54

First, as a public health

31:56

expert on TV and Twitter, and

31:58

now as the White House's COVID

32:00

nineteen response

32:02

coordinator. He's been

32:04

sending pandemic for a long time.

32:06

And next week, he'll tell us what

32:08

it's really like to try to manage

32:10

one from the front lines.

32:12

One of the things that you realize is you can have

32:14

app absolutely brilliant ideas

32:16

that just cannot be implemented. That's

32:18

all coming up next week on FreakonomicsMD.

32:20

Thanks again for listening.

32:22

Fri

32:24

reopenomics MD is part of

32:26

the Freakonomics Radio Network, which

32:28

also includes freak Economics Radio, no

32:31

stupid questions, and

32:33

people I mostly admire. All

32:35

our shows are produced by Stitcher

32:37

and run by radio. You can find us on Twitter

32:39

at doctor BabuPod. This

32:42

episode was produced by Julie

32:44

offer and mixed by Jasmine Klinger, with help

32:46

from Jeremy Johnston. Our staff

32:48

also includes

32:49

Neil Carruth, Gabriel Rob,

32:51

Greg Ripon, Leark

32:52

Foutage, Rebecca Lee Douglas, Morgan

32:55

Levy, Zach LaPinski, Ryan

32:57

Kelly, Catherine Mancurr, Eleanor

32:59

Osbourne, Daria Klineert, Emma

33:01

Terrell, Alina Coleman and

33:03

Steven Dubner, original

33:05

music composed by Louise Gara. If

33:07

you like this show or any

33:09

other show in the Freakonomics Radio

33:11

Network, please recommend it to your family

33:13

and friends. That's the best way

33:15

to support the podcast you love.

33:18

As always, thanks for

33:20

listening. The

33:24

actor Ryan

33:24

Reynolds got a colonoscopy. And I

33:26

was thinking, I'm gonna look at what happens

33:28

the colonoscopy rates after Ryan

33:31

Reynolds got his broadcast

33:33

at colonoscopy. His experience

33:35

went

33:35

really well and there were no

33:37

complications that we know of

33:38

then for what it's worth. He's protected

33:41

for a large number of years

33:43

to come. The

33:47

Freakonomics Radio Network,

33:48

the hidden

33:49

side of everything.

33:52

stitcher.

33:56

What

33:59

will it take

33:59

to

33:59

conserve ten billion acres

34:02

of ocean one point six billion

34:04

acres of land and over six

34:06

hundred thousand miles of river. What will it

34:08

take to protect and restore

34:10

natural habitats in over

34:12

seventy countries around the world and in

34:14

all fifty states here at home.

34:16

What will it take?

34:17

You. Together,

34:18

the dinner We will

34:19

make it happen. It's in our nature.

34:22

See how your gift can help. At

34:24

nature dot org, the

34:25

nature conservancy. protecting nature,

34:30

preserving life.