cullen: why most published research is wrong

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Why most published research is wrong.” Louise Cullen (Clinician researcher)

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Question everything! Louise cullen examines the minefield of published research and importance of reading around topics, not articles.

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Page 1: Cullen: Why most published research is wrong

“Why most published

research is wrong.”

Louise Cullen(Clinician researcher)

Page 2: Cullen: Why most published research is wrong

Disclosure Information

Page 3: Cullen: Why most published research is wrong

“It is everyone’s responsibility to find out how to

ask questions systematically, find answers from searching the

literature, critically appraise the literature

and apply the results to practice.”

Rinaldo Bellomo

Page 4: Cullen: Why most published research is wrong

“It is everyone’s responsibility to find out how to

ask questions systematically, find answers from searching the

literature, critically appraise the literature

and apply the results to practice.”

Rinaldo Bellomo

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Page 7: Cullen: Why most published research is wrong

40 ingredients associate with cancer

Most single studies showed implausibly large effects.

Page 8: Cullen: Why most published research is wrong

The p value

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The p value

Observed size of Effect

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p=0.01

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p=0.01

There is a 1% chance of results as extreme as these would occur when there is really no difference occurring in the experiment.

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1000 hypotheses

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Replication of studies

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Replication of studies

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Problems with the study itself.

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Wrong question

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Wrong Theory

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Wrong population studied

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2

ACS: Trial and community populations

Circulation. 115(19):2549-69, 2007 May 15.

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n=2

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Wrong design

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• Greater the flexibility in– designs – definitions – outcomes– analytical modes

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• Greater the flexibility in– designs – definitions – outcomes– analytical modes

• Hotter a scientific field with more teams involved.

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Wrong Endpoints

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Ad and high dose Ad

Ca++ in cardiac arrest

COX-2 inhibitors

Milrinone

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Methodology

Statistical hypothesis inference testing

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Problems with reporting

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Interpretation

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• “a little significance”

• “a definite trend is evident”

• “a clear tendency”

• “almost achieved significance”

Page 40: Cullen: Why most published research is wrong

• “a little significance”

• “a definite trend is evident”

• “a clear tendency”

• “almost achieved significance”

The data is practically

meaningless

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• “In my experience”• “In case after case”• “In a series of cases”

• “It is generally believed that..”

• “A highly significant area for exploratory study”

• Once• Twice• Three times

• A couple of others think so too

• A totally useless topic in my underpowered study…….

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Omitting facts deliberately

….!

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Why?

Incentives

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Pharma

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Pharma

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Why?

Ethical practice of researchers

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Problems with publishing

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Don’t believe in the review process

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Journal publishing practices

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• 2004 “original articles” in NEJM– 363 tested an established therapy– 146 (40%) reversed that practice– 138 (38%) reaffirmed it

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What can you do about it?

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Read more than the title!

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Reporting Framework

CONSORT (http://bit.ly/14qUNEF)– Standards for reporting of trials

STARD– Standards for the Reporting of diagnostic accuracy

studies

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Biases

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Be sceptical!

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Thank you

@louiseacullen