FIRST PARTIAL
Purpose of the EBM
EBM is a system for acquiring and evaluating evidence to generate knowledge that changes clinical behavior
EBM takes us from the clinical problem to its answer.
The EBM process: I find the problem → I ask a question → I search for literature → I evaluate the literature →
I evaluate the applicability of the literature → I act on my patient
Evaluating the literature implies 2 things: to see if it is reliable (biases) and the degree of impact (measures of
association)
When evaluating the applicability of the literature, I must also determine 2 things: if there is similarity with the
population studied and if the outcome is relevant for my patient
EBM Basics
EBM has 3 fundamentals: (1) know and find the best evidence (2) evaluate the evidence (3) go beyond the
evidence
The 0, fundamental, basal principle of EBM is to have good clinical foundations because I will NOT find the
correct answer if I ask the question wrong, and the question depends on my diagnosis.
Knowing the best evidence requires being up-to-date
The type of evidence that constitutes the “best” evidence depends on the question
For therapeutic/harm: RTC, observational, basic science experiments, clinical experience
Prognosis: prospective cohort is TOP
Risk factors: cases and controls
Disease burden and resource allocation: Cross-sectional (measure prevalence at a point in time)
Information Gaps: Systematic Review
Incidence in a given time: Longitudinal descriptive. (Well, for the cohorts, the main one is the relationship
between them)
There are elements that can change the level of "best" evidence, this hierarchy. GRADE has some criteria
They increase the quality: dose response, magnitude of the effect
They lower the quality: indirect, imprecise, inconsistent, biased
For EBM it is essential to know all the evidence, not just the one that favors me, which is why systematic
reviews are considered very TOP.
The question
The design of the question depends on its objective.
Treatment or harm question: PICO (Population, intervention, comparator, outcome)
Dx question: IOP (Population, intervention, gold standard)
Prognosis Question: IOP (Population, Intervention (time), outcome
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