2023 NR 503 Final Study Guide (Version-2), Final Exam
NR 503 Population Health, Epidemiology & Statistical
Principles, Chamberlain.
1. Objectivesof
... [Show More] epidemiology
a. Understand the aetiologyor cause of adisease (risk factors)
b. Find outthe extentthat a disease or health problemaffects a community or
population
c. Determine the natural history orprognosis
d. Evaluateexisting and newlydevelopedpreventativetherapeuticmeasures and
modes of healthcare delivery
2. Define, compare, calculate, and interpret Measures ofMorbidity
a. Incidence rate: measurement ofthe number of new individuals who contract a
disease during a particular period of time
i. Calculation:Number of new cases of disease orinjury during specified
period DIVIDED BY Size of population at start of period
b. Attack rate: Same asrisk,proportion ofindividualsin apopulation (initially freeof
disease) who develop the disease within a specified time interval.
i. Calculation: Totalnumber of new casesDIVIDEDBY The total population
c. Prevalence: measurement of all individuals affected by the disease at aparticular
time
i. Calculation:Number of new cases of disease orinjury during specified
period DIVIDED BY Time each person was observed, totaled for all
persons
d. These rates are used to measure disease occurrence and make comparisons
between population groups. They are commonlyusedmeasuresthat help our
understanding of the distribution of disease in a given population.
3. Understand why incidence data are importantformeasuring risk.
a. Incidence isimportantformeasuring risk because ittells you the rate at which
new people are contracting the disease
4. Define, compare, calculate, andinterpret Measures ofMortality
a. Mortality: a measure of the frequency of occurrence of death in a defined
population during a specified interval. Morbidity and mortality measures are
often the samemathematically; it'sjust amatter of what you choose tomeasure,
illness or death.
i. Calculation:Deaths occurring during a given time period DIVIDED BY Size
of the population amongwhich the deaths occurred TIMES 10n
b. Cause-specific mortality rate: Themortality rate froma specified cause for a
population.
i. Calculation: The number of deaths attributed to a specific cause DIVIDED
BY The size ofthe population at the midpoint of the time period
c. Annual mortality rate: The rate of death in a one-year period.
i. Calculation:Deaths occurringwithin the one-yearperiod DIVIDED BY Size
of population in which the deaths occured
d. Case-fatality: the proportion of deaths within a designated population of "cases"
(people with a medical condition) overthe course of the disease
i. Calculation: he number of deaths from a specified disease over a defined
period of time DIVIDED BY The number of individuals diagnosed with the
disease during thattime TIMES 100 (final answershould be percentage)
e. Proportionate mortality: the proportion of deathsin a particular population overa
specified period of time, attributable to different causes
i. Calculation: Number of deaths within a population due to a specific
disease or causeDIVIDEDBY the total number of deathsin the population
during a time period such as a year.
5. AssesstheValidity and ReliabilityofDiagnostic andScreeningTests
a. Define, compare andcalculatemeasuresof validity, including sensitivity and
specificity.
i. Sensitivity identifies the proportion of individuals who truly DO have the
disease AND are given a positive test result. I find it helpful to remember:
sensiTivity = sensitive to the Truth (i.e. do have disease + do have positive
result)
1. We want to know what proportion of individuals who have the
disease (a+c) were given a positive testresult(a), therefore…
a. Sensitivity = a/(a+c)
ii. Specificity identifiesthe proportion ofindividuals who trulyDONOT have
the disease AND were given the correct negative test result. I find it
helpful to remember: specificity = speciFies the False (i.e. do not have
disease and do not have positive test result
1. Thistime we want to know what proportion of people who do not
have the disease (b+d) were given the correct negative test result
(d), therefore…
a. Specificity = d/(b+d).
b. Defineand calculate positivepredictive value.
i. Positive Predictive Value: The probability thatsubjects with apositive
screening test truly have the disease.
1. Calculation: a/(a+c)
c. Understand positive predictive value (PPV) and relationshiptodisease
prevalence and specificity of a screening test.
i. Higherprevalence/specificityrates=higherppvrates
6. Epidemiologic transition
a. Phase of development witnessed by a sudden and stark increase in populatio [Show Less]