Evidence Based Medicine Flashcards
When is EBM used?
it is only a tool in clinical decision making, clinicians should use critically appraised information for optimal patient care
not used as the ultimate reason behind clinical decisions
What should not be considered to assess causality?
disease prevalence
What is critical for a causal pathway between exposure and outcome?
temporal relationship
What does bias lead to?
incorrect estimate of association
How can this bias best be addressed?
considering potential bias in study
What is most important when deciding whether to prescribe homeopathic medicine?
systematic review
Why does EBM matter to clinicians?
BETTER SERVICE FOR PATIENTS patient care and safety medical knowledge professionalism revalidation - to be up to date practice based learning and improvement
What are some criticisms of EBM?
academic exercise - no relevance to clinical practice
time consuming
EBM jargon used to justify decisions is not appropriate
What is the role of EBM in clinical medicine?
CLINICAL FINDINGS - how to gather/interpret findings from history/physical examination properly
AETIOLOGY - identify disease causes (iatrogenic forms)
CLINICAL MANIFESTATIONS - knowing how often/when disease manifests clinically
DIFFERENTIAL DIAGNOSIS - select patients serious/responsive to treatment
DIAGNOSTIC TESTS - how to select /interpret diagnostic tests, confirm exclude diagnosis based on precision, accuracy, expense, safety
PROGNOSIS - how to estimate patients likely clinical course, anticipate complications
THERAPY - how to select treatments to offer, weigh up risks and benefits
PREVENTION - reduce chance of disease by identifying risk factors, how to diagnose early via screening
Hierarchy of studies
Systematic review/meta analysis
- avoid large sample size/cost of RCTs
- use series of smaller studies to select upon quality and then do analysis
- pool results to give results for larger study
RCTs
- gold standard for CTs, surgical interventions
- treatment effect demonstrated needs to be large
- expensive
Cohort
- group of people before condition then observe exposures/risk factors
- better for common conditions
- less prone to bias
Case control
- better for rare conditions
Ecological studies
- descriptive study using correlations between populations with different exposures
Descriptive/cross sectional study
- surveys/analysis on routinely taken data
- hard to show causal relationship
- surveys, census
Case report/series
- not evidence used to support practice
- describes a/some cases
- useful to pick out new syndromes/conditions
What principle is homeopathy based on?
like causes like
ultra-diluted so no longer harmful
NHS spends 4 million/year treating 54,000 patients in 4 homeopathic hospitals
Only 2 NHS funded as there is no evidence to support homeopathic treatments
How do RCTs work?
comparison against placebos (controls)
people allocated randomnly
What are negatives to RCTs?
inappropriate controls missing trials (hidden trials to make results bias)
What is the MMR vaccine?
combines 3 vaccines
given 2 stages - 12/15 months, 3/5 yrs
death of children catching disease dropped since introduced in 1988
What did mumps cause?
viral meningitis
