ebm or cases or both? - tom jefferson

EBM or cases or both?

Tom JeffersonCochrane Ari Group , Cochrane Vaccines Field etc

Jefferson.tomail.comThanks to Dr Massimo Arlotti, Sebastiano Leone, Fabio

Franzetti, Evangelo Boumis, Angelo Pan

Celebrating case reports and stories in health care

EBM

• Mainly based on comparative studies (esp. their synthesis)

• Randomised Controlled Trial/tightly controlled experimental paradigm

• Non-randomised (comparative) studies


Problems

• Inductive methods• Uniformity of nature• Abstraction and generalisation• Patients in front of you not quite the same as

those in trials



Repeated observation across different contexts

Induction

Theories and general principles

Deduction

Conclusions andexplanations

The arch of knowledge

When do we need case knowledge?

• Heavy contextualisation• Rare diseases• Harm monitoring• When controls are not available or not ethical• When other evidence is tainted


Guidelines for treating Serious Gram-Positive infections (Italian GISIG project)

• Systematic reviews of cases of:

• Endocarditis• Brain abscesses• Joint / prostheses infections


Infective endocarditis(Dr Boumis)

Reporting variable No missing / 19 reports

Age 1

Comorbidities/risk factors 1

Symptom duration 3

Symptom descr 4

Physical examination findings 7

Imaging data 3

Lab data 13

Which valve involved 1

Agente sensitivity (MIC) 2

Antibiotic dosage 11

Antibiotic tx duration 6

Outcome description 4

Follow up duration 5Celebrating case reports and stories in health care

Standardisation

• Demographic/contextual variables• Prognostic profile• Diagnostic variables• Treatement• Harms• Outcome• Sufficient information to allow follow through

by singles or groups of all these variables


Tom Jefferson Beware of red herringsHow to read and listen to scientific items - Bufala spotting

Case report quick assessment

NOIs the topic of interest?

YES

Is presentation clear?

YES

NO

Is the narrative logical? NO

YES

Is there a a declarationof conflicts?

NO

YESIs the sponsoridentifiable?

NO

YES

Can you reproduce the pathway?

YES NO

Are off-lables used

Are there ethical Problems?

No Yes

Warning

• Standardisation required (“tell the story”)• Coordination desperately needed• Web 2.0 to Web 3.0• Huge numbers• Always interpret case evidence in the context

of the current body of evidence


ebm or cases or both? - tom jefferson

Business