tutorial 2 Flashcards
epidimiology
Study of the occurrence and distribution of the health-related diseases and events in specified populations, including the study of determinants influencing such states, and the application of this knowledge to control the health problem.
purpose of epidimiology
to investigate nature/ extent of health-related phenomena in the community
to study natural history and prognosis of health-related problems
to identify causes and risk factors
to recommend in application of best interventions
to provide foundation for public policy
Broad types of epidimiology
descriptive and analytic
Descriptive
testing a specific hypothesis about the relationship of a disease to a specific cause, by conducting an epidemiologic study that relates the exposure of interest to the outcome of interest.
typical study designs: cohort, case-control, experimental design.
analytic
examining the distribution of a disease and a observing the basic features of its distribution in terms of time
typical study design: corss-sectional study, descriptive study
5w’s of descriptive epidimiology
what=health issue of concern who= person where- place when= time why/how= causes, risk factors, modes of transmission
epidimiology explained in 7 steps
define population of interest
conceptualize and create measures of exposure and health indicators
take a sample of the population
estimate measures of association between exposures and health inidcatorsof interest
rigorously evaluate whether the association observed suggest a casual association
assess the evidence for causes working together
assess the extent to which the results matters, is externally valid, to other populations
epidimiologist
cases or health event and describes them in terms of time, place and person
divides the number of cases by an appropriate denominator to calculate rates
compares these rates over time
cahian of infection
infectious agent reservior portal of exit mode ofg transmission portal of entry susceptible host
incubation
the time interval from exposure to an infectious agent to the onset of symptoms of an infectious disease
induction
time interval between exposure and pathological onset
latency
time from exposure to a casual agent to onset of symptoms of a disease
sojourn
inerval between disease detectable and onset of symptoms
endemic
refers to the constant resence and/ or usual prevelance of a disease or infectious agent in a population within a geographic area,
epidemic
refers to the increase, often sudden, in the number of cases of a disease above what is normally expected in that population
pandemic
refers to an epidemic that has spread over several countries or continents, usually affecting a large number of people
prevalence
the number of proportion of cases or events or attributes among a given population
incidence
a measure of the frequency with, which, new cases of illness, injury, or other health conditionsoccurs among a population duringa specified period
pathogenecity
the ability of an agent to cause disease after infection, measured as the proportion of persons by an agent who then experience clinical disease
virulence
the ability of an infectious agent to cause severe disease, measured as the proprtion of persons with the disease who become severely ill or die
infectivity
the ability of an infectious agent to cause infection, measured as the proportion of persons exposed to an infectious agent who become infected
outbreak
the occurence of more cases of disease, injury or other health conditions than expected in a given area or among a specific group of persons during a specific period
line listing
type of epidemiologic databas, organised similar to a spreadsheet with rows and columns in which information from cases or patients are listed. each column represents a variable and each row represents an individual case or patient
reproductive rate
the number of people infected by a case or how many one infected person will transmit the disease to.
r0 >
1 disease will become epidemic
r0=
1 disease will become endemic
r0
1 disease will disappear
