association and causation Flashcards
define a Cause
an event, condition or characteristic (or a combo of these) that plays an essential role in producing an occurrence of disease
whats the whole pie in causal pie model
whole pie is a sufficient cause of the outcome
what is a segment of sufficient cause called
its a component cause
whats a necessary cause
a compontent cause which is necessary for the outcome to occur. it must be a part of every sufficient cause
how do we determine if something is causal
we first consider if the association is valid and isn’t internally biased, then we use judgement according to BESTCDS
whats BESTCDS
the bradford hill guidelines in determing if causation has occurred.
biological plausibility, experimental evidence, specificity, temporal sequence, consistency, dose response relationship, strength of association
define biological plausability
is there a plausible biological mechanism for association to cause the outcome. we may not know sometimes as epidemiological findings can proceed biological knowledge
define experimental evidence
is there evidence for the association from RCt or animal studies, animal studies may not always be applicable
define specificty
is the exposure associated only with this outcome and not others, vice versa. often exposures relate to many outcomes
define temporal sequence
does the exposure come before the association
define consistency
are the findings of this study comparible, similar, consistent with findings of other studies
define dose response relationship
does the risk of outcome change with varying levels of the exposure. this is not applicable for binary exposures. also not all exposure relationships are linear
define strength of association
how large is the value of the MoA, so the stronger the found association the less likely it is due to confounding or bias
