Evidence-Based Medicine

Vocabulary flashcards covering key terms, definitions, and concepts from the Evidence-Based Medicine lecture.

Evidence-Based Medicine

A philosophy and practice of medicine based on knowledge and understanding of medical literature and research; supports and directs clinical decision making

Lewis Thomas

criticized human experimentation

Frederick II

human trials

Jan Baptista van Helmont

randomized control trials

Pierre Charles Alexandre Louis

retrospective statistical analysis

The Fundamentals of EBM

awareness of the best evidence to optimize clinical decision making

guidance on whether evidence can be trusted

evidence alone is not enough for decision making

Clinical Trial Steps

Convert

Find

Appraise

Implement

Evaluate

Clinical Trial: Appraise

assess validity and applicability of information gathered

Clinical Trial: Find

find best evidence to answer question

Clinical Trial: Convert

make sure information is in form of an answerable question

EBM Process Steps

Search

Interpret

Evaluate

Apply

Goal of EBM

To use the BEST evidence to IMPROVE care of individual patients

EBM Aids

computer decision support

restricted pharmaceutical formularies

clinical practice guidelines

decision aids

Benefits of EBM

Cochrane Collaboration

Publication Standards

Clinical Practice Guidelines

Education for Critical Appraisal

Increase Knowledge Base

Cochrane Collaboration

where evidence from clinical trials is summated

Challenges of EBM

Quality Mark

Too Much Evidence

Marginal Gains

Overemphasis on Rules

Changing Patient Population

Study Design Determinants

therapy

harm

diagnosis

progno

Primary Research: Definition

basic research, clinical trials, epidemiological traits

Primary Research: Types

randomized controlled trials

controlled clinical trials

observational studies

Randomized Controlled Trial

Experimental study where participants are randomly allocated to treatment or control.

Pros of Randomized Trials

evaluate a single variable

prospective design

allows meta-analysis

unbiased distribution

Cons of Randomized Trials

expensive

time consuming

surrogate endpoints

hidden bias

Observational Studies

Experimental study where participants are naturally exposed to potential harm or not exposed

Pros of Observational Studies

feasible when you can’t randomize

smaller sample size

can be prospective or retrospective

Cons of Observational Studies

susceptible to bias

low relevance

can take many years

Subclassifications of Observational Studies

cohort studies

case control studies

cross-sectional studies

Cohort study

Follow exposed vs unexposed groups over time

Prospective analysis

Cross-sectional study

analyzing data from a population at a single point in time

Retrospective analysis

Case-control study

Compare patients with condition to those without

Can be prospective or retrospective

Experimental Primary Research

randomized controlled trials

non-randomized controlled trials

involve treatment and/or exposure to therapy

Observational Primary Research

descriptive or analytical

exposure and outcome relationship

may or may not involve comparison group

Assigned Exposure, Random Allocation

randomized controlled trial

Assigned Exposure, No Random Allocation

non-randomized controlled trial

No Assigned Exposure, No Comparison Group

descriptive study

No Assigned Exposure, Has Comparison Group, Exposure then Outcome

cohort study

No Assigned Exposure, Has Comparison Group, Outcome then Exposure

case-control study

No Assigned Exposure, Has Comparison Group, Exposure & Outcome Simultaneously

cross-sectional study

Structure: Studies of Differential Diagnoses

clinical presentation →

diagnostic evaluation →

diagnosis

Structure: Studies of Diagnostic Test Properties

patients possibly having target condition →

diagnostic tests →

gold standard test →

condition present or absent

Structure: Studies of Prognosis

patients at risk of experiencing target event →

prognostic factor →

time →

experience or not experience target event

Secondary Research

systematic reviews and meta-anlysis

Systematic Review

focuses on clinical topic or question

identifies relevant studies

assess/review all studies

summarizes results

Meta-analysis

examines multiple studies

combines results

provides singular result

Hierarchy of Evidence (weakest to strongest)

Case Reports, Opinion Papers, Letters →

Animal Trials & In Vitro Studies →

Cross Sectional Studies →

Case Control Studies →

Cohort Studies →

RCTs →

Meta Analyses & Systematic Reviews

Case Series & Case Reports

detailed description of 1 patient or small group

hypothesis generating

Expert Opinion & Background Information

based on experience, consensus, or unsystematic review of evidence

GRADE

rank by study quality and context

GRADE: Systematic Reviews & Meta-Analysis

evidence graded on quality, not just study type; start as high quality, can be downgraded

GRADE: RCTs

start as high quality; can be downgraded for bias risk, inconsistency, indirectness, imprecision, publication bias

GRADE: Cohort Studies

start as low quality; can be upgraded if strong effect or dose-response

GRADE: Case Control Studies

start at low quality; can be upgraded if strong effect or dose response

GRADE: Case Reports/Series

start as very low quality; rarely upgraded

GRADE: Expert Opinion

very low quality; may guide practice if no other evidence