Lecture 1 Flashcards
Evidence-based medicine is
Use of mathematical estimates of risk of benefit & harm, derived from high-quality research on population samples, to inform clinical decision-making in the diagnosis, investigation, or management of individual patients
EBM practice emphasizes
best evidence, clinical expertise, patient values & circumstances
Basic steps
- Ask answerable questions
- Search for best evidence
- Critical appraisal for validity & relevance
- Integrate evidence, clinical expertise, & patient values/preferences & apply
- Evaluate results
Answerable questions consist of:
PICO Patient or problem Intervention Comparison intervention Outcomes
Best medicine should be
patient-centered
What is the best source for evidence
Electronic online sources
Current, recently updated, & evidence-based
Most reliable studies are
Systematic Reviews (or meta-analyses) of RCTs (followed by Randomized, controlled trials)
Least reliable studies are
Case reports
Hierarchy of study reliability:
- Systematic Reviews (or meta-analyses) of RCTs
- Randomized, controlled trials
- Prospective studies
- Retrospective studies
- Cross-sectional surveys
- Case series
- Case reports
Are prospective or retrospective studies more reliable?
Prospective studies
Systematic reviews present
evaluations of groups of studies relating to diagnosis & screening, therapy, prognosis, & Harm/risk/etiology
Descriptive statistics
Involves collecting data, presenting data, & characterizing data in order to describe data
Inferential statistics
Involves estimation & hypothesis testing in order to make decisions about population characteristics
Experimental units (elements)
Object upon which we collect data
Sometimes called units of analyses
Population
All items of interest
Statistic coming from whole population is called a parameter
Sample
Subset of units of a population
Statistics come from samples
Variable
Characteristic of an individual experimental unit
Symbol of event, act, trait, or attribute that can be measured & we assign some values
Categorical Variable
Some numeric or character codes that represent either the presence or absence of something that is of interest OR
the relative weight or rank of the thing that is of interest
Quantitative variable
Variable that holds the numerical result of some measurement usually taken using some standard unit
Process
Series of actions or operations that transforms inputs to outputs; produces output over time
Nominal Scale
Simplest level of measurement - categories without order
i.e. hair color