Ben Goldacre: Battling Bad Science

768,347 views ・ 2011-09-30

TED


Dvaput kliknite na engleske titlove ispod za reprodukciju videozapisa.

Prevoditelj: Zlatko Smetisko Recezent: Katarina Smetko
00:15
So I'm a doctor, but I kind of slipped sideways into research,
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Liječnik sam, ali sam malo skrenuo s puta i zašao u polje istraživanja
00:18
and now I'm an epidemiologist.
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tako da sam sada epidemiolog.
00:20
And nobody really knows what epidemiology is.
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Nitko ne zna što je zapravo epidemiologija.
00:22
Epidemiology is the science of how we know in the real world
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Epidemiologija je znanost o tome kako znamo
00:25
if something is good for you or bad for you.
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je li nešto dobro ili loše za nas.
00:27
And it's best understood through example
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Primjerom je to najbolje objasniti
00:29
as the science of those crazy, wacky newspaper headlines.
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kao znanost iza onih ludih, šašavih novinskih natpisa.
00:34
And these are just some of the examples.
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Ovo su samo neki od primjera.
00:36
These are from the Daily Mail.
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Ovo su novinski natpisi iz Daily Maila - svaka država na svijetu ima novine poput ovih.
00:38
Every country in the world has a newspaper like this.
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Imaju taj stalni bizarni filozofski projekt
00:40
It has this bizarre, ongoing philosophical project
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dijeljenja svih neživih stvari
00:43
of dividing all the inanimate objects in the world
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na one koje ili uzrokuju ili sprečavaju rak.
00:45
into the ones that either cause or prevent cancer.
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00:47
Here are some of the things they said cause cancer:
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Neke od stvari za koje tvrde da uzrokuju rak jesu:
razvod, Wi-Fi, toaletne potrepštine i kava.
00:50
divorce, Wi-Fi, toiletries and coffee.
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Neke od stvari za koje kažu da sprečavaju rak:
00:52
Some things they say prevent cancer:
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kora kruha, crvena paprika, slatkiši i kava.
00:54
crusts, red pepper, licorice and coffee.
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Već primjećujete proturječnosti.
00:56
So you can see there are contradictions.
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Kava i uzrokuje i sprečava rak.
00:58
Coffee both causes and prevents cancer.
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Kad nastavite čitati dalje, počinjete shvaćati
01:00
As you start to read on, you can see
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01:01
that maybe there's some political valence behind some of this.
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da iza ovakvih primjera stoji nekakva politička pozadina.
01:04
For women, housework prevents breast cancer,
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Kućanski poslovi sprečavaju rak dojke kod žena,
01:06
but for men, shopping could make you impotent.
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dok shopping može dovesti do impotencije kod muškaraca.
01:09
(Laughter)
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Vidimo kako moramo početi
01:10
So we know that we need to start unpicking the science behind this.
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odvajati znanstvene činjenice od svega toga.
01:15
And what I hope to show is that unpicking the evidence behind dodgy claims
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Nadam se da ću pokazati
kako odvajanje sumnjivih tvrdnji,
odvajanje dokaza iza takvih tvrdnji,
01:21
isn't a kind of nasty, carping activity;
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nije mukotrpna aktivnost,
01:24
it's socially useful.
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već je društveno korisno,
01:26
But it's also an extremely valuable explanatory tool,
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ali i iznimno vrijedno
kao sredstvo objašnjavanja.
01:30
because real science is about critically appraising the evidence
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Bit prave znanosti jest
kritičko procjenjivanje dokaza s drugog stajališta.
01:33
for somebody else's position.
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Na taj način funkcioniraju znanstveni časopisi.
01:35
That's what happens in academic journals,
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Tako funkcioniraju znanstvene konferencije.
01:37
it's what happens at academic conferences --
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Vrijeme pitanja i odgovora, nakon što su podaci izloženi,
01:39
the Q&A session after a postdoc presents data is often a bloodbath.
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postaje mjesto oštrih napada,
01:42
And nobody minds that; we actively welcome it.
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što nikome ne smeta. Aktivno se podržava.
01:44
It's like a consenting intellectual S&M activity.
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Nalikuje odobrenoj intelektualnoj sado mazo aktivnosti.
01:47
(Laughter)
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Ono što ću vam pokazati
01:49
So what I'm going to show you is all of the main things,
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jesu glavne stvari,
glavne karakteristike moje discipline --
01:52
all of the main features of my discipline, evidence-based medicine.
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medicine koja se temelji na dokazima.
01:55
And I will talk you through all of these and demonstrate how they work,
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Proći ću s vama kroz te karakteristike
i pokazati vam kako funkcioniraju,
01:59
exclusively using examples of people getting stuff wrong.
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koristeći isključivo primjere u kojima su ljudi nešto krivo shvatili.
02:02
We'll start with the absolute weakest form of evidence known to man,
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Počet ćemo s najslabijim mogućim oblikom dokaza poznatim čovjeku:
autoritetom.
02:06
and that is authority.
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Nas u znanosti ne zanima koliko titula imate uz ime.
02:08
In science, we don't care how many letters you have after your name --
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Zanimaju nas razlozi zbog kojih vjerujete u nešto.
02:11
we want to know what your reasons are for believing something.
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Kako znate je li nešto dobro
02:14
How do you know that something is good for us or bad for us?
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ili loše za nas?
02:17
But we're also unimpressed by authority because it's so easy to contrive.
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Autoritet nas ne impresionira
jer ga je lako izmisliti.
02:21
This is somebody called Dr. Gillian McKeith, PhD,
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Ovo je netko tko se zove Dr. Gillian McKeith, dr.sc.,
ili punom liječničkom titulom - Gillian McKeith.
02:24
or, to give her full medical title, Gillian McKeith.
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(Smijeh)
02:27
(Laughter)
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Svaka zemlja ima nekoga poput nje.
02:30
Again, every country has somebody like this.
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Ona je naš televizijski prehrambeni guru.
02:32
She is our TV diet guru.
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02:33
She has five series of prime-time television,
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Ima nevjerojatnih 5 sezona televizijskog serijala u udarnom terminu
02:36
giving out very lavish and exotic health advice.
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u kojem daje ekstravagantne i egzotične zdravstvene savjete.
02:39
She, it turns out, has a non-accredited correspondence course PhD
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Ispostavilo se da ima doktorat s nepriznatog dopisnog tečaja
odnekud iz Amerike.
02:43
from somewhere in America.
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02:44
She also boasts that she's a certified professional member
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Hvali se, također, kako je i akreditirani stručni član
Američkog udruženja nutricionističkih savjetnika,
02:47
of the American Association of Nutritional Consultants,
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što zvuči nadasve glamurozno i uzbudljivo.
02:49
which sounds very glamorous; you get a certificate.
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Od njih dobijete potvrdu i sve.
02:52
This one belongs to my dead cat, Hettie. She was a horrible cat.
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Ova pripada mojoj mrtvoj mački Hetti. Bila je to grozna mačka.
Samo otiđete na njihovu web stranicu, ispunite formular
02:55
You go to the website, fill out the form,
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i uplatite 60 dolara, a oni vam pošalju potvrdu poštom.
02:57
give them $60, it arrives in the post.
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No, to nije jedini razlog zbog kojeg ovu osobu smatramo idiotom.
02:59
That's not the only reason we think this person is an idiot.
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Ona tvrdi stvari poput --
03:01
She also says things like eat lots of dark green leaves,
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trebate jesti mnogo tamnozelenog lišća
03:04
they contain chlorophyll and really oxygenate your blood.
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jer ono sadrži mnogo klorofila, što će dovesti mnogo kisika u vašu krv.
Svatko tko je imao biologiju u školi sjetit će se
03:07
And anybody who's done school biology remembers
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da klorofil i kloroplasti
03:09
that chlorophyll and chloroplasts only make oxygen in sunlight,
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stvaraju kisik samo na sunčevom svjetlu,
03:12
and it's quite dark in your bowels after you've eaten spinach.
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a u našim je crijevima posve mračno nakon što se pojeli špinat.
Potrebna nam je prava znanost, sa stvarnim dokazima.
03:16
Next, we need proper science, proper evidence.
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03:18
So: "Red wine can help prevent breast cancer."
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„Crno vino pomaže u sprečavanju raka dojke“.
Ovo je naslov članka iz britanskog Daily Telegrapha.
03:21
This is a headline from The Daily Telegraph in the UK.
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„Čaša crnog vina dnevno može pomoći u sprečavanju raka dojke“.
03:23
"A glass of red wine a day could help prevent breast cancer."
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Otiđete i nađete taj članak, i otkrit ćete
03:26
So you find this paper, and find that it is a real piece of science.
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kako se radi o pravom znanstvenom radu.
03:29
It's a description of the changes in the behavior of one enzyme
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Radi se o opisu promjena kod jednog enzima
03:32
when you drip a chemical extracted from some red grape skin
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kad nakapate kemijski ekstrakt iz kože crnog grožđa
na stanice raka,
03:36
onto some cancer cells
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03:37
in a dish on a bench in a laboratory somewhere.
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koje se nalaze u nekoj petrijevoj posudi na nekom stolu u nekom laboratoriju.
03:40
And that's a really useful thing to describe in a scientific paper.
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Ovo je stvarno korisno opisana stvar
u znanstvenom časopisu,
03:44
But on the question of your own personal risk of getting breast cancer
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ali po pitanju osobnog rizika
i dobivanju raka dojke, ukoliko pijete crno vino,
03:48
if you drink red wine,
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kaže vam frišku figu.
03:49
it tells you absolutely bugger all.
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Zapravo, čini se da se rizik od raka dojke
03:51
Actually, it turns out that your risk of breast cancer
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neznatno povećava
03:53
increases slightly with every amount of alcohol you drink.
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pri svakoj količini popijenog alkohola..
03:56
So what we want are studies in real human people.
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Ono što zahtijevamo jesu studije na stvarnim ljudima.
04:00
And here's another example.
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Evo još jednog primjera.
04:02
This is from Britain's "leading" diet nutritionist in the Daily Mirror,
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Ovaj dolazi od glavnog britanskog prehrambenog i nutricionističkog savjetnika u Daily Mirroru,
drugim najprodavanijim britanskim novinama.
04:06
our second-biggest selling newspaper.
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„Istraživanje provedeno u Australiji 2001. godine
04:08
"An Australian study in 2001 found that olive oil,
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otkriva kako maslinovo ulje u kombinaciji s voćem, povrćem i mahunarkama
04:10
in combination with fruits, vegetables and pulses,
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vidljvo štiti kožu od bora“.
04:12
offers measurable protection against skin wrinklings,"
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Zatim slijedi savjet:
04:15
and give the advice:
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„Ako jedete maslinovo ulje i povrće, imat ćete manje bora“.
04:16
"If you eat olive oil and vegetables, you'll have fewer wrinkles."
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Još vam vrlo susretljivo kažu kako doći do tog istraživanja.
04:19
They helpfully tell you how to find the paper,
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Kad pronađete to istraživanje, vidjet ćete kako se radi o opservacijskom istraživanju.
04:22
and what you find is an observational study.
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Očito je da se nitko nije vratio
04:24
Obviously, nobody has been able to go back to 1930,
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u 1930. godinu,
sakupio sve ljude rođene u jednom rodilištu,
04:27
get all the people born in one maternity unit,
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04:29
and half of them eat lots of fruit and veg and olive oil,
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polovici dao da jede puno voća i povrća i maslinovog ulja,
a drugoj polovici hranu iz McDonald'sa,
04:32
half of them eat McDonald's,
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04:33
and then we see how many wrinkles you've got later.
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a zatim kasnije ustanovio koliko bora imaju.
Ono što morate napraviti jest uzeti ljude u sadašnjem trenutku.
04:36
You have to take a snapshot of how people are now.
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I otkrit ćete, naravno,
04:38
And what you find is, of course:
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kako ljudi koji jedu povrće i maslinovo ulje imaju manje bora.
04:40
people who eat veg and olive oil have fewer wrinkles.
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04:42
But that's because people who eat fruit and veg and olive oil are freaks --
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No, to je zato što su ljudi koji jedu voće i povrće i maslinovo ulje
čudaci, oni nisu normalni, oni su poput vas;
04:46
they're not normal, they're like you; they come to events like this.
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dolaze na događaje poput ovog.
04:50
(Laughter)
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Radi se o dotjeranim i bogatim ljudima, s manje mogućnosti da rade posao na otvorenom,
04:51
They're posh, they're wealthy, less likely to have outdoor jobs,
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ili fizički posao,
04:54
less likely to do manual labor,
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04:55
they have better social support, are less likely to smoke;
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imaju bolju društvenu podršku, manje su mogućnosti da puše --
već se sada radi o nizu fascinantnih, međusobno povezanih
04:58
for a host of fascinating, interlocking
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društvenih, političkih i kulturalnih razloga
05:00
social, political and cultural reasons,
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zbog kojih su manje vjerojatnosti da imaju bore.
05:02
they're less likely to have wrinkles.
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Ne radi se, dakle, samo o povrću i maslinovom ulju.
05:04
That doesn't mean it's the vegetables or olive oil.
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(Smijeh)
05:06
(Laughter)
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Idealno, ono što želite napraviti jest ispitivanje.
05:08
So ideally, what you want to do is a trial.
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05:10
People think they're familiar with the idea of a trial.
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Svi misle da su dobro upoznati s pojmom ispitivanje.
Ispitivanja su vrlo stara. Prvo se dogodilo u Bibliji – Danijel 1:12.
05:13
Trials are old; the first one was in the Bible, Daniel 1:12.
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Vrlo je jednostavno -- uzmete hrpu ljudi, podijelite ih u dvije jednake grupe,
05:16
It's straightforward: take a bunch of people, split them in half,
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jednu grupu tretirate na jedan način, drugu na drugi način,
05:19
treat one group one way, the other group, the other way.
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vratite im se nešto kasnije
05:21
A while later, you see what happened to each of them.
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i vidite što se dogodilo sa svakom od njih.
Ispričat ću vam o jednom ispitivanju
05:24
I'm going to tell you about one trial,
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koje je u posljednjem desteljeću vjerojatno medijski najpraćenije
05:26
which is probably the most well-reported trial
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u Britaniji.
05:28
in the UK news media over the past decade.
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Radi se o ispitivanju kapsula ribljeg ulja.
05:30
This is the trial of fish oil pills.
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Tvrdilo se da kapsule ribljeg ulja poboljšavaju rezultate u školi i ponašanje
05:32
The claim: fish oil pills improve school performance and behavior
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prosječne djece.
05:35
in mainstream children.
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Rekli su, „Napravili smo ispitivanje.
05:36
They said, "We did a trial.
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05:37
All the previous ones were positive, this one will be too."
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Sva su prijašnja ispitivanja bila pozitivna, tako da znamo da će i ovo biti takvo“.
Takva bi izjava odmah trebala biti znak za uzbunu.
05:40
That should ring alarm bells:
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Ako već znate ishod svog ispitivanja, onda ga ne biste trebali raditi.
05:42
if you know the answer to your trial, you shouldn't be doing one.
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Ili ste ga unaprijed namjestili
05:45
Either you've rigged it by design,
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05:46
or you've got enough data so there's no need to randomize people anymore.
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ili imate dovoljno podataka pa nema potrebe za istraživanjem prema slučajnom odabiru.
Ispitivanje je bilo ovako organizirano.
05:50
So this is what they were going to do in their trial:
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05:52
They were taking 3,000 children,
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Uzeli su 3 000 djece
05:54
they were going to give them these huge fish oil pills, six of them a day,
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i svima su davali velike kapsule ribljeg ulja,
šest na dan,
05:58
and then, a year later, measure their school exam performance
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a zatim su, godinu dana kasnije, izmjerili njihove razultate na školskom ispitu
06:01
and compare their performance
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i usporedili ih
06:03
against what they predicted their exam performance would have been
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s onime što su pretpostavili da bi bili rezultati
da ta djeca nisu uzimala kapsule.
06:06
if they hadn't had the pills.
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06:08
Now, can anybody spot a flaw in this design?
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Primjećuje li netko rupu u tom ispitivanju?
06:11
(Laughter)
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Profesori metodologije kliničkog ispitivanja
06:12
And no professors of clinical trial methodology
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06:14
are allowed to answer this question.
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ne smiju odgovoriti na ovo pitanje.
06:16
So there's no control group.
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Nema kontrolne skupine; kontrolna skupina ne postoji.
06:18
But that sounds really techie, right? That's a technical term.
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Ali to zvuči previše stručno.
To je stručnan termin.
06:21
The kids got the pills, and their performance improved.
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Djeca su dobila kapsule i njihov se rezultat poboljšao.
06:24
What else could it possibly be if it wasn't the pills?
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Što bi drugo uopće moglo biti objašnjenje ako nisu pilule?
Odrasla su. Svi se s vremenom razvijamo.
06:28
They got older; we all develop over time.
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06:30
And of course, there's the placebo effect,
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Naravno, postoji i placebo efekt.
06:32
one of the most fascinating things in the whole of medicine.
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Placebo efekt jedna je od najfascinantnijih stvari u cijeloj medicini.
Ne radi se samo o uzimanju tablete, vašem poboljšanju i smanjenju boli.
06:35
It's not just taking a pill and performance or pain improving;
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Radi se o našim vjerovanjima i očekivanjima.
06:38
it's about our beliefs and expectations, the cultural meaning of a treatment.
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Radi se o kulturalnom značenju liječenja.
Ovo je dokazano na cijelom nizu fascinantnih istraživanja
06:42
And this has been demonstrated in a whole raft of fascinating studies
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u kojima se jedna vrsta placebo efekta upoređivala s drugom.
06:45
comparing one kind of placebo against another.
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06:47
So we know, for example,
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Znamo, primjerice, da su dvije šećerne tablete na dan
06:48
that two sugar pills a day are a more effective treatment
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učinkovitije u liječenju želučanih čireva
06:51
for gastric ulcers
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od jedne šećerne tablete.
06:52
than one sugar pill.
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Dvije su šećerne tablete bolje od jedne.
06:54
Two sugar pills a day beats one a day.
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Ovo je nečuveno i apsurdno otkriće, ali je istinito.
06:56
That's an outrageous and ridiculous finding, but it's true.
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06:58
We know from three different studies on three different types of pain
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Iz triju različitih istraživanja o tri različite vrste boli znamo
da je injekcija slane vode učinkovitiji način liječenja boli
07:02
that a saltwater injection is a more effective treatment
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od uzimanja šećerne tablete, uzimanja placebo tablete --
07:04
than a sugar pill, a dummy pill with no medicine in it,
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07:07
not because the injection or pills do anything physically to the body,
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ne zbog nekog fizičkog učinka injekcije ili tablete na tijelo,
07:10
but because an injection feels like a much more dramatic intervention.
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već zbog toga što injekcija predstavlja dramatičniju intervenciju.
Znamo da se našim vjerovanjima i očekivanjima
07:14
So we know that our beliefs and expectations can be manipulated,
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može manipulirati
07:17
which is why we do trials where we control against a placebo,
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zbog čega se i provode istraživanja
u kojima se ispituje placebo efekt --
07:21
where one half of the people get the real treatment,
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u kojima polovica ljudi dobiva pravi lijek,
07:23
and the other half get placebo.
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a druga polovica placebo.
07:25
But that's not enough.
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No to nije dovoljno.
07:28
What I've just shown you are examples
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Pokazao sam vam primjere jednostavnih i laganih načina
07:30
of the very simple and straightforward ways
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na koje novinari, trgovci dodacima prehrani
07:32
that journalists and food supplement pill peddlers and naturopaths
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i naturopati
07:35
can distort evidence for their own purposes.
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iskrivljuju dokaze sebi u korist.
07:38
What I find really fascinating
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Ono što mene fascinira
07:40
is that the pharmaceutical industry uses exactly the same kinds
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jest da farmaceutska industrija
koristi iste smicalice i načine,
07:43
of tricks and devices,
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ali malo sofisticiranije oblike istih,
07:45
but slightly more sophisticated versions of them,
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07:47
in order to distort the evidence they give to doctors and patients,
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kako bi iskrivila dokaze koje podnosi doktorima i pacijentima,
a koje koristimo kako bismo donijeli vrlo važne odluke.
07:51
and which we use to make vitally important decisions.
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07:53
So firstly, trials against placebo:
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Prvo, ispitivanja protiv placebo efekta:
svi misle kako bi se istraživanje trebalo temeljiti
07:56
everybody thinks a trial should be a comparison
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na usporedbi novog lijeka i placeba.
07:58
of your new drug against placebo.
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U mnogim je slučajevima takav pristup pogrešan.
08:00
But in a lot of situations that's wrong;
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Često već imamo vrlo dobar lijek koji je trenutno dostupan,
08:02
often, we already have a good treatment currently available.
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pa ne želimo znati kako je vaš nov alternativan lijek
08:05
So we don't want to know that your alternative new treatment
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bolje od ničega.
08:08
is better than nothing,
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Želimo znati da je bolji od trenutno najboljeg dostupnog lijeka.
08:09
but that it's better than the best available treatment we have.
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Ali neprestano vidimo kako ljudi rade ispitivanja
08:12
And yet, repeatedly, you consistently see people doing trials
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uspoređujući ih s placebom.
08:15
still against placebo.
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1306
08:16
And you can get licensed to bring your drug to market
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I možete dobiti dozvolu za plasiranje lijeka na tržište
08:18
with only data showing that it's better than nothing,
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samo na temelju podataka koji pokazuju da je vaš lijek bolji od ničega,
što je meni kao liječniku beskorisno kad pokušavam donijeti odluku.
08:21
which is useless for a doctor like me trying to make a decision.
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Nije ovo jedini način kako namjestiti podatke.
08:24
But that's not the only way you can rig your data.
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2365
Podatke možete namjestiti
08:26
You can also rig your data
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tako da ono s čime uspoređujete svoj novi lijek
08:28
by making the thing you compare your new drug against
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izgleda kao sranje.
08:30
really rubbish.
195
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1157
08:31
You can give the competing drug in too low a dose,
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Konkurentni lijek možete davati u premalenim količinama,
pa ljudi ne dobivaju prikladno liječenje.
08:34
so people aren't properly treated.
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Ili ga možete davati u prevelikim količinama,
08:36
You can give the competing drug in too high a dose,
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tako da uzrokuje nuspojave.
08:38
so people get side effects.
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08:39
And this is exactly what happened
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Upravo se to dogodilo
08:41
with antipsychotic medication for schizophrenia.
201
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2465
s antipsihoticima za shizofreniju.
08:43
Twenty years ago, a new generation of antipsychotic drugs were brought in;
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3532
Prije 20 godina tržištu je predstavljena nova generacija antipsihotika
s obećanjem da uzrokuju manje nuspojava.
08:47
the promise was they would have fewer side effects.
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2557
Počela su se raditi ispitivanja, usporedbe novih lijekova
08:50
So people set about doing trials of the new drugs against the old drugs.
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3454
i starih,
08:53
But they gave the old drugs in ridiculously high doses:
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2685
ali stari su lijekovi bili davani u nevjerojatno visokim dozama --
20 miligrama haloperidola dnevno.
08:56
20 milligrams a day of haloperidol.
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1845
Unaprijed je određeno
08:58
And it's a foregone conclusion if you give a drug at that high a dose,
207
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3554
da ako ljudima dajete lijek u tako visokim dozama
09:01
it will have more side effects, and your new drug will look better.
208
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imat će više nuspojava, a vaš će novi lijek izgledati bolje.
Prije 10 godina, povijest se ponovila
09:05
Ten years ago, history repeated itself,
209
545063
1988
sa, začuđujuće, risperidonom, prvim lijekom nove generacije antipsihotika
09:07
when risperidone, the first of the new-generation antipsychotic drugs,
210
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3325
čije je autorsko pravo isteklo pa se mogao kopirati.
09:10
came off copyright, so anybody could make copies.
211
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2342
09:12
Everybody wanted to show their drug was better than risperidone,
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3032
Svi su htjeli pokazati kako je njihov lijek bolji od risperidona
pa ste mogli pronaći hrpu istraživanja u kojima su se novi antipsihotici
09:15
so you see trials comparing new antipsychotic drugs
213
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2401
uspoređivali sa risperidonom u dozi od osam miligrama dnevno.
09:18
against risperidone at eight milligrams a day.
214
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2167
Ne radi se tu o nekoj ludoj ili ilegalnoj dozi,
09:20
Again, not an insane dose, not an illegal dose,
215
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2214
ali o dozi koja je na gornjoj granici normalne.
09:22
but very much at the high end of normal.
216
562700
1918
Tako da će vaš lijek zasigurno izgledati bolje.
09:24
So you're bound to make your new drug look better.
217
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2517
Nije začuđujuće, gledano sveukupno,
09:27
And so it's no surprise that overall,
218
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2597
09:29
industry-funded trials are four times more likely
219
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2769
da će istraživanja financirana od strane farmaceutske industrije
četiri puta vjerojatnije dati pozitivan rezultat
09:32
to give a positive result
220
572597
1329
09:33
than independently sponsored trials.
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2053
nego nezavisno financirana istraživanja.
09:36
But -- and it's a big but --
222
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2644
Ali -- i to je veliko ali --
09:39
(Laughter)
223
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2521
(Smijeh)
ispada da
09:42
it turns out,
224
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1281
09:43
when you look at the methods used by industry-funded trials,
225
583507
3641
kad usporedite metode korištene u istraživanjima farmaceutskih industrija,
da su ta istraživanja zapravo bolja
09:47
that they're actually better than independently sponsored trials.
226
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3686
od nezavisno financiranih ispitivanja.
09:50
And yet, they always manage to get the result that they want.
227
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2892
Ali svejedno uspiju dobiti rezultat koji žele.
09:53
So how does this work?
228
593798
1150
Kako to funkcionira?
09:54
(Laughter)
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1013
Kako možemo objasniti ovaj čudan fenomen?
09:56
How can we explain this strange phenomenon?
230
596009
2767
09:58
Well, it turns out that what happens
231
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1798
Ispada da se to događa
10:00
is the negative data goes missing in action;
232
600622
2233
zbog toga što negativni podaci nestanu;
10:02
it's withheld from doctors and patients.
233
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1937
podaci se uskrate doktorima i pacijentima.
10:04
And this is the most important aspect of the whole story.
234
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2698
Ovo je najvažniji dio cijele priče.
Nalazi se na vrhu piramide dokaza.
10:07
It's at the top of the pyramid of evidence.
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2034
Potrebni su nam svi podaci o određenom lijeku
10:09
We need to have all of the data on a particular treatment
236
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kako bismo znali je li učinkovit ili nije.
10:12
to know whether or not it really is effective.
237
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2160
Postoje dva različita načina na koje možete primijetiti
10:14
There are two different ways you can spot whether some data has gone missing.
238
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3667
jesu li neki podaci nestali.
Možete koristiti statistiku ili priče.
10:18
You can use statistics or you can use stories.
239
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2199
10:20
I prefer statistics, so that's what I'll do first.
240
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2389
Osobno, više volim statistiku, pa ću se prvo pozabaviti njome.
10:22
This is a funnel plot.
241
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1322
Postoji nešto što se zove ljevkasti grafikon.
10:24
A funnel plot is a very clever way of spotting
242
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2191
On predstavlja pametan načim zamjećivanja
10:26
if small negative trials have disappeared, have gone missing in action.
243
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3365
jesu li maleni negativni pokusi nestali, je li ih pojela noć.
10:29
This is a graph of all of the trials done on a particular treatment.
244
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3478
Ovo je grafikon svih ispitivanja
učinjenih za određeni lijek.
10:33
As you go up towards the top of the graph,
245
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2255
Kako se primičete vrhu grafikona
10:35
what you see is each dot is a trial.
246
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1929
vidite da svaka točka predstavlja jedno ispitivanje.
10:37
As you go up, those are bigger trials, so they've got less error;
247
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3126
Kako idete prema vrhu, ispitivanja su sve veća pa imaju manje pogrešaka.
10:40
they're less likely to be randomly false positives or negatives.
248
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3146
Manja je vjerojatnost da će biti nasumični lažni pozitivi ili lažni negativi.
10:43
So they all cluster together.
249
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1392
Svi su zajedno skupljeni.
10:45
The big trials are closer to the true answer.
250
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2507
Veća su ispitivanja bliža točnom odgovoru.
10:47
Then as you go further down at the bottom,
251
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2016
Kako se spuštate prema dnu grafikona,
10:49
what you can see is, on this side, spurious false negatives,
252
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2919
ono što vidite na ovoj strani jesu patvoreni lažni negativi,
10:52
and over on this side, spurious false positives.
253
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2246
a na ovoj strani patvoreni lažni pozitivi.
Ako postoje sustavne greške objavljivanja,
10:55
If there is publication bias,
254
655045
2076
ako su mali negativni pokusi nestali,
10:57
if small negative trials have gone missing in action,
255
657145
2530
10:59
you can see it on one of these graphs.
256
659699
1815
možete to primijetiti na jednom od ovih grafikona.
11:01
So you see here that the small negative trials
257
661538
2151
Ovdje vidite kako su mali negativni pokusi,
11:03
that should be on the bottom left have disappeared.
258
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2453
koji su se trebali nalaziti dolje lijevo, nestali.
Ovo je grafikon koji pokazuje prisutnost sustavne pogreške objavljivanja
11:06
This is a graph demonstrating the presence of publication bias
259
666190
2935
u istraživanjima sustavnih progrešaka objavljivanja.
11:09
in studies of publication bias.
260
669149
1920
Mislim da je ovo najsmješniji epidemiološki vic
11:11
And I think that's the funniest epidemiology joke you will ever hear.
261
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3302
koji ćete ikad čuti.
11:14
(Laughter)
262
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1011
Ovako to dokazujete statistički,
11:15
That's how you can prove it statistically.
263
675454
2024
ali što je s pričama?
11:17
But what about stories?
264
677502
1151
11:18
Well, they're heinous, they really are.
265
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1915
One su gnusne, stvarno jesu.
11:20
This is a drug called reboxetine.
266
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1589
Ovo je lijek reboksetin.
11:22
This is a drug which I, myself, have prescribed to patients.
267
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2939
Ovaj sam lijek osobno prepisivao pacijentima.
Ja sam stvarno štreberski liječnik.
11:25
And I'm a very nerdy doctor.
268
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1336
11:26
I hope I go out of my way
269
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1312
Svim se silama trudim pročitati i razumjeti svu literaturu.
11:27
to try and read and understand all the literature.
270
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2359
Čitao sam ispitivanja o ovom lijeku. Sva su bila pozitivna. Sva su bila dobro provedena.
11:30
I read the trials on this.
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1308
11:31
They were all positive, all well-conducted.
272
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2267
Nisam našao zamjerku.
11:33
I found no flaw.
273
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1151
Nažalost, na kraju se ispostavilo
11:35
Unfortunately, it turned out, that many of these trials were withheld.
274
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3581
da su mnoga ispitivanja bila zatajena.
11:38
In fact, 76 percent of all of the trials that were done on this drug
275
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4545
Točnije, 76 posto
svih ispitivanja napravljenih na ovom lijeku
bilo je zatajeno liječnicima i pacijentima.
11:43
were withheld from doctors and patients.
276
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1951
Kad razmislite o tome,
11:45
Now if you think about it,
277
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1253
11:46
if I tossed a coin a hundred times,
278
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2297
ako bacim novčić stotinu puta
11:48
and I'm allowed to withhold from you the answers half the times,
279
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3536
i dozvoljeno mi je zatajiiti vam
rezultate polovice tih bacanja,
11:52
then I can convince you that I have a coin with two heads.
280
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4089
mogu vas uvjeriti
da imam novčić s dvije glave.
11:56
If we remove half of the data,
281
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1913
Ako polovicu podataka uklonimo
11:58
we can never know what the true effect size of these medicines is.
282
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3738
nikad ne možemo znati kakav točno učinak ima ovaj lijek.
Ovo nije jedina takva priča.
12:02
And this is not an isolated story.
283
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2071
Zatajeno je oko polovice svih rezultata ispitivanja o antidepresivima.
12:04
Around half of all of the trial data on antidepressants has been withheld,
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3794
ali tu priča ne staje.
12:08
but it goes way beyond that.
285
728101
1436
12:09
The Nordic Cochrane Group were trying to get ahold of the data on that
286
729561
3346
Grupa Nordic Cochrane pokušala je prikupiti podatke o tome,
u želji da ih ujedini.
12:12
to bring it all together.
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1195
Grupa Cochrane internacionalna je neprofitna udruga
12:14
The Cochrane Groups are an international nonprofit collaboration
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3019
koja objavljuje sustavne preglede svih podataka ikada prikazanih.
12:17
that produce systematic reviews
289
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1490
12:18
of all of the data that has ever been shown.
290
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2097
Potreban im je pristup svim podacima ispitivanja.
12:20
And they need to have access to all of the trial data.
291
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2534
No, tvrtke im uskraćuju podatke,
12:23
But the companies withheld that data from them.
292
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2443
12:25
So did the European Medicines Agency --
293
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2195
kao i Europska agencija za lijekove,
i to zadnje tri godine.
12:28
for three years.
294
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1586
12:29
This is a problem that is currently lacking a solution.
295
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3032
Problem je to kojem trenutno nedostaje rješenje.
12:32
And to show how big it goes, this is a drug called Tamiflu,
296
752738
2899
Da vam pokažem koliko daleko to ide: ovo je lijek Tamiflu,
12:35
which governments around the world
297
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1662
na koji su vlade diljem svijeta
12:37
have spent billions and billions of dollars on.
298
757347
2843
potrošile milijarde i milijarde dolara.
Potrošile su taj novac jer su se povodile za obećanjem
12:40
And they spend that money on the promise that this is a drug
299
760214
2867
kako će ovaj lijek smanjiti stopu komplikacija
12:43
which will reduce the rate of complications with flu.
300
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2972
vezanih uz gripu.
Već imamo podatke
12:46
We already have the data
301
766101
1151
12:47
showing it reduces the duration of your flu by a few hours.
302
767276
2794
koji pokazuju da smanjuje trajanje gripe za par sati.
No, to mene ne zanima. Vlade to ne zanima.
12:50
But I don't care about that, governments don't care.
303
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2454
Žao mi je ako imate gripu, znam da je to grozno,
12:52
I'm sorry if you have the flu, I know it's horrible,
304
772572
2454
ali ne ćemo potrošiti milijarde dolara
12:55
but we're not going to spend billions of dollars
305
775050
2244
kako bismo smanjili trajanje simptoma vaše gripe
12:57
trying to reduce the duration of your flu symptoms by half a day.
306
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3162
za pola dana.
13:00
We prescribe these drugs.
307
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1325
Prepisujemo ovakve lijekove, gomilamo rezerve za hitne slučajeve
13:01
We stockpile them for emergencies
308
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1803
pod uvjetom da će smanjiti broj komplikacija,
13:03
on the understanding they'll reduce the number of complications,
309
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3089
što znači sprečavanje upale pluća i smrti.
13:06
which means pneumonia and death.
310
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1534
Grupa Cochrane koja se bavi zaraznim bolestima, sa sjedištem u Italiji,
13:08
The infectious diseases Cochrane Group, which are based in Italy,
311
788351
3459
pokušava dobiti
13:11
has been trying to get the full data in a usable form
312
791834
3177
sve podatke od farmaceutskih tvrtki, u razumljivom obliku,
13:15
out of the drug companies,
313
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1268
kako bi mogla donijeti odluku
13:16
so they can make a full decision
314
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2091
13:18
about whether this drug is effective or not,
315
798442
2097
je li taj lijek djelotvoran ili nije.
13:20
and they've not been able to get that information.
316
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2966
Do sada nisu uspjeli dobiti te informacije.
13:23
This is undoubtedly the single biggest ethical problem
317
803553
5206
Ovo je, bez sumnje,
najveći etički problem
13:28
facing medicine today.
318
808783
1976
s kojim se suočava današnja medicina.
Ne možemo donositi odluke
13:31
We cannot make decisions in the absence of all of the information.
319
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5333
ako nemamo sve informacije.
13:37
So it's a little bit difficult from there
320
817789
2977
Teško je završiti
13:40
to spin in some kind of positive conclusion.
321
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3446
nekim pozitivnim zaključkom.
Ali rekao bih ovo:
13:45
But I would say this:
322
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1631
13:48
I think that sunlight
323
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2796
mislim da je sunčeva svjetlost
13:51
is the best disinfectant.
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najbolji dezinficijens.
Sve se ovo događa nama pred nosom,
13:54
All of these things are happening in plain sight,
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13:56
and they're all protected by a force field of tediousness.
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a oni su svi zaštićeni
zaštitnim poljem sporosti.
14:01
And I think, with all of the problems in science,
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Smatram, sa svim problemima u znanosti,
da najbolje što možemo napraviti
14:04
one of the best things that we can do
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14:05
is to lift up the lid, finger around at the mechanics
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jest podići pokolopac,
počeprkati po mehanici i zaviriti unutra.
14:08
and peer in.
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Hvala vam najljepša.
14:10
Thank you very much.
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14:11
(Applause)
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(Pljesak)
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