history of epidemiology Flashcards
Why were John Snow’s investigations of the Broad Street cholera epidemic considered innovative (select all that apply)?
One of the first observational studies where he tested the hypothesis by collecting data systematically & comparing groups of people
He argued for an intervention to prevent more cases (removing the pump handle)
He proposed a new hypothesis that contaminate water was the cause of cholera
who was james lind?
person to first conduct research on scurvy
who was william farr?
assessed births, marriages and deaths while using census data in the denominator
who was john graunt
he summarized patterns of mortality in 17th century london
what is a cause?
is can be many things where a causes b
b causes b
something else, x, causes both a and b
or systematic bias of the observations
or even by chance
what are the Bradford hill (BH) guidelines
guidelines to help determine if associations are causal
what are the 9 guidelines to Bradford hill?
strength of association, consistency, specificity, temporality, biological gradient, plausibility, coherence, experiment, analogy
describe BH guideline 1 strength of association
the large the association the more likely the exposure is causing the disease
describe BH guideline 2 consistency
the association is observed repeatedly in different persons, places, times, and circumstances
describe BH guideline 3 specificty
a single exposure should cause a single disease
describe BH guideline 4 temporality
the causal factor must preced the disease in time
describe BH gudleine 5 bilogical gradient
a ‘dose response’ relationship b/w exposure and disease. Persons who have increasingly higher exposure levels have increasingly higher risk of disease
describe BH guideline 6/7 plasuability/coherence
biological or social model exists to ecplain the association
associations do not conflict w current knowledge of natural history and biology of disease
describe BH guideline 8 experiment
investigator-intiate intervention that mdofies the exposure through prevention, treatment or removal should result in less disease
describe Bh guidline 9 analogy
has a similar relationship been observed w another exposure and or disease?
