FINAL WEEK 8: EPIDEMIOLOGY
epidemiology6-6ans--
_______________6is6the6study6of6the6distribution6and6determinants6of6health-
related6states6or6events6(including6disease),6and6the6application6of6this6study6to6the6contr
ol6of6diseases6and6other6health6problems
epi6-6ans--upon
demos6-6ans--people
logos6-6ans--thought
Descriptive6epidemiology6-6ans--
§6Or6patterns6of6health6events6in6populations6in6order6to6characterize6health6outcomes6in
6terms6of6what,6who,6where,6when,6how6and6why:6What6is6the6outcome?6Who6is6affected
?6Where6are6they?6When6do6events6occur?6This6focus6isà6descriptive6epidemiology
person,6place,6time6-6ans--
Descriptive6epidemiology6looks6at6______,6_______,6and6______
person6-6ans--
Descriptive6epidemiology:6o6Gender,6age,6race,6education,6occupation,6socioeconomic6s
tatus,6marital6status
place6-6ans--Descriptive6epidemiology:
o6Chemical,6physical,6biological6environment6or6population6densities6or6behavioral/lifesty
le
time6-6ans--Descriptive6epidemiology:
o6Long6term6trends,6point6epidemic,6cyclical6patterns,6event-related6clusters
analytic6epidemiology6-6ans--
§6Reference6to6the6goal6of6understanding6the6etiology6(or6origins6and6causal6factors)6of6d
isease;6the6broad6consideration6of6many6levels6of6potential6determinants6if6called6the6ec
ological6approach
§6Search6for
·6Cause6and6effects
·6Why6and6how
·6Epidemiologists6use6analytic6epidemiology6to6quantify6the6association6between6exposu
res6and6outcomes6and6to6test6hypotheses6about6casual6relationships
, o6Observational6studies,6cohort,6case6control,6cross6sectional
analytic6-6ans--__________6epidemiology6looks6at6descriptive6comparisons
descriptive6-6ans--__________6epidemiology6sheds6light6on6determinants
hippocrates6-6ans--
§6On6airs,6waters,6and6places,6suggests6environmental6and6host6factors6such6as6behavio
rs6might6influence6the6development6of6disease
john6snow6-6ans--§6Father6of6Epidemiology,6cholera6epidemic
Florence6Nightingale6-6ans--
§6Statistician,6social6reformer6and6founder6of6modern6nursing
§6Improved6outcomes6for6soldiers
Lillian6Wald6-6ans--§6New6York,6TB
agent,6host,6environment6-6ans--
What6are6the6three6components6of6the6epidemiological6triangle?
agent6-6ans--
·6Agent6originally6referred6to6an6infectious6agent:6a6virus,6bacterium,6parasite,6or6other6mi
crobe.6Generally,6the6agent6must6be6present6for6disease6to6occur;6however,6presence6of6
that6agent6alone6is6not6always6sufficient6to6cause6disease.6
·6A6variety6of6factors6influence6whether6exposure6to6an6organism6will6result6in6disease,6in
cluding6the6organism's6pathogenicity6(ability6to6cause6disease)6and6dose.
·6Over6time,6the6concept6of6agent6has6been6broadened6to6include6chemical6and6physical6
causes6of6disease6or6injury.
Environment6-6ans--
·6Environment6refers6to6extrinsic6factors6that6affect6the6agent6and6the6opportunity6for6exp
osure.
·6Environmental6factors6include:6
o6Physical6factors:6geology6and6climate,6
o6Plant6and6animal6life:6agents,6reservoirs6or6habitats
o6Human6population6distribution:6crowding,6social6supports
o6Socioeconomic6factors:6resources,6education,6access6to6care
Working6conditions:6noise,6stress,6satisfaction
host6-6ans--·6A6variety6of6factors6intrinsic6to6the6host,6
·6sometimes6called6risk6factors,6can6influence6an6individual's6exposure,6susceptibility,6or6
response6to6a6causative6agent
·6Susceptibility6and6response6to6an6agent6are6influenced6by6factors6such6as6genetic6com
position,6age6or6sex,6and6immunologic6status,6presence6of6disease6or6medications,6and6
psychological6makeup.
epidemiology6-6ans--
_______________6is6the6study6of6the6distribution6and6determinants6of6health-
related6states6or6events6(including6disease),6and6the6application6of6this6study6to6the6contr
ol6of6diseases6and6other6health6problems
epi6-6ans--upon
demos6-6ans--people
logos6-6ans--thought
Descriptive6epidemiology6-6ans--
§6Or6patterns6of6health6events6in6populations6in6order6to6characterize6health6outcomes6in
6terms6of6what,6who,6where,6when,6how6and6why:6What6is6the6outcome?6Who6is6affected
?6Where6are6they?6When6do6events6occur?6This6focus6isà6descriptive6epidemiology
person,6place,6time6-6ans--
Descriptive6epidemiology6looks6at6______,6_______,6and6______
person6-6ans--
Descriptive6epidemiology:6o6Gender,6age,6race,6education,6occupation,6socioeconomic6s
tatus,6marital6status
place6-6ans--Descriptive6epidemiology:
o6Chemical,6physical,6biological6environment6or6population6densities6or6behavioral/lifesty
le
time6-6ans--Descriptive6epidemiology:
o6Long6term6trends,6point6epidemic,6cyclical6patterns,6event-related6clusters
analytic6epidemiology6-6ans--
§6Reference6to6the6goal6of6understanding6the6etiology6(or6origins6and6causal6factors)6of6d
isease;6the6broad6consideration6of6many6levels6of6potential6determinants6if6called6the6ec
ological6approach
§6Search6for
·6Cause6and6effects
·6Why6and6how
·6Epidemiologists6use6analytic6epidemiology6to6quantify6the6association6between6exposu
res6and6outcomes6and6to6test6hypotheses6about6casual6relationships
, o6Observational6studies,6cohort,6case6control,6cross6sectional
analytic6-6ans--__________6epidemiology6looks6at6descriptive6comparisons
descriptive6-6ans--__________6epidemiology6sheds6light6on6determinants
hippocrates6-6ans--
§6On6airs,6waters,6and6places,6suggests6environmental6and6host6factors6such6as6behavio
rs6might6influence6the6development6of6disease
john6snow6-6ans--§6Father6of6Epidemiology,6cholera6epidemic
Florence6Nightingale6-6ans--
§6Statistician,6social6reformer6and6founder6of6modern6nursing
§6Improved6outcomes6for6soldiers
Lillian6Wald6-6ans--§6New6York,6TB
agent,6host,6environment6-6ans--
What6are6the6three6components6of6the6epidemiological6triangle?
agent6-6ans--
·6Agent6originally6referred6to6an6infectious6agent:6a6virus,6bacterium,6parasite,6or6other6mi
crobe.6Generally,6the6agent6must6be6present6for6disease6to6occur;6however,6presence6of6
that6agent6alone6is6not6always6sufficient6to6cause6disease.6
·6A6variety6of6factors6influence6whether6exposure6to6an6organism6will6result6in6disease,6in
cluding6the6organism's6pathogenicity6(ability6to6cause6disease)6and6dose.
·6Over6time,6the6concept6of6agent6has6been6broadened6to6include6chemical6and6physical6
causes6of6disease6or6injury.
Environment6-6ans--
·6Environment6refers6to6extrinsic6factors6that6affect6the6agent6and6the6opportunity6for6exp
osure.
·6Environmental6factors6include:6
o6Physical6factors:6geology6and6climate,6
o6Plant6and6animal6life:6agents,6reservoirs6or6habitats
o6Human6population6distribution:6crowding,6social6supports
o6Socioeconomic6factors:6resources,6education,6access6to6care
Working6conditions:6noise,6stress,6satisfaction
host6-6ans--·6A6variety6of6factors6intrinsic6to6the6host,6
·6sometimes6called6risk6factors,6can6influence6an6individual's6exposure,6susceptibility,6or6
response6to6a6causative6agent
·6Susceptibility6and6response6to6an6agent6are6influenced6by6factors6such6as6genetic6com
position,6age6or6sex,6and6immunologic6status,6presence6of6disease6or6medications,6and6
psychological6makeup.
