CH LM 9
Epidemiology
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Epidemiology
Purpose
Pasteur Lister Koch John Snow Nightingale
Basic Concepts
Diagnostic Descriptive Investigative Experimental Analytical
Intervention Decision-Making Monitoring
Sources of data Rate Adjustment Comparison Groups
Study of the distribution & factors that determine health-related states/events in a population; use of this info to control
health problems.
Det. causes of health
& dz in population
Monitor health in the
pop.
ID determinates of
health & dz in comm.
Investigate/eval.
interventions to prevent dz
& maintain health
History - 19th
Century
Proved spontaneous
generation wrong;
germ theory;
pasteurization
(heating just enough
to kill microbes);
rabies vaccine
Established sterilization
techniques/antiseptics;
transformed surgery.
Discovered causal
agents for anthrax, TB
& cholera; dev. causal
criteria
"Father of epidemiology"
Showed association btw
cholera & water supply;
conducted a "natural
experiment"
Using rates of
illness per 1,000
soldiers, was able to
show that improving
environ. conditions
& nursing care
decreased mortality
rates.
Measures morbidity & mortality - rates, proportions, risk, ratio, incidence, prevalence (proportion, attack rates, mortality
rates)
Stagesof the
epidemiologic
process
Presence of dz
confirmed
Describes pop. @ risk &
distribution of dz
Hyothesis may be
formed ab. poss.
determinants of the dz
Involves implementing
a series of field studies
to test hypothesis
Experiments performed
under controlled
conditions
Results are
analyzed, combined
with attempts to
model epidemiology
of the dz
Methods for control
of the dz examined
(experiment
conditions or in the
field)
Explore options for
control of dz. Model
effects of options on dz
incidence. Examine cost
& control measures to
compare with benefits
During implementation
of the control measures
to ensure they're
properly applied &
having the desired
effect
Basic methods in
epidemiology
Routinely collected data (census)
Data collected for other purposes (med records)
Original data (specifically collected for
epidemiology)
Age-adjusted
Direct-adjusted
Indirect-adjusted
To decide if dz is a result
of suspected risk factor.
Compare exposed group
with unexposed group.
