Causation And Study Design Flashcards
Case control?
Condition present in group so look back at risk factors
Cohort study used to calculate?
Incidence/ and identify exposures
Split participants to who have had exposure and who haven’t
Difference between cohort and case control?
Cohort- they have exposure and check for outcome
Case control- selected by outcome status then check for exposures
What is RCT used for?
Test safety and efficacy of interventions
Groups should be identical before intervention is provided
Case study?
One patient and descriptive in terms of experience of disease and treatment
Which study design has greatest evidence for causal association?
RCT
Analytic studies?
Providing evidence between cause and association e.g RCT, case control and cohort
Difference between observational and experimental studies?
Experimental provides intervention, but in observational you never affect anything, natural occurring circumstances
Cofounder?
Third variable exerting influence, possibly causing a and b, both dependent and independent variable causing a spurious association
Bradford hill criteria?
Linking cause and outcome
Bradford hill criteria includes?
Strength of association Consistency Specificity Temporality Plausibility Coherence Biological gradient Experimental evidence Analogy
Only RCT design can do all of this
What is temporality?
Exposure proceding disease
Biological gradient?
Increased exposure corresponds to increased disease
Coherence?
Association consistent with other knowledge of the topic
Plausibility?
Rational scientific basis for exposure disease association
What is a cross sectional study?
A defined population is surveyed to simultaneously measure disease and exposure
With inclusion and exclusion criteria
In a case control the sample is selected based on?
Outcome status
And then you try to identify relevant exposures
Always retrospective- past exposures
In a cohort study sample based on?
Exposure
Used to calculate incidence of the disease
Can be retrospective and prospective
An RCT is used to?
Tests safety, efficacy of interventions
