NURS 420 Exam 3 UPDATED ACTUAL
Questions and CORRECT Answers
Who is John Snow? - CORRECT ANSWER -The father of epidemiology
He found the source of the 1850's cholera outbreak in London
What is epidemiology? - CORRECT ANSWER -It investigates the distribution of health events in a
population (who, what, when, where, why)
What is descriptive epidemiology? - CORRECT ANSWER -Describes disease according to person,
place, time
What is analytic epidemiology? - CORRECT ANSWER -Describes origins or causes of disease
(how/why)
What is a big indicator of health in a community? - CORRECT ANSWER -Infant mortality rate
How do you calculate rate? - CORRECT ANSWER -Number events divided by population at risk,
then multiplied by 100,000
In 2017 there were 2,813,503 deaths in the U.S.
647,457 of the deaths were caused by heart disease
What was the proportion of deaths attributed to heart disease? - CORRECT ANSWER -0.23, or
23.0%
All cases are called what? - CORRECT ANSWER -Prevalence
New cases are called what? - CORRECT ANSWER -Incidence
Define incident rate - CORRECT ANSWER -rate of development of new cases in a population at
risk
,Define incidence proportion - CORRECT ANSWER -proportion of population at risk that
experiences the event over some period of time
At a hospital screening program for breast cancer, 8000 women were screened.
35 were previously diagnosed with breast cancer
20 with no history of breast cancer were found to have cancer of the breast - CORRECT
ANSWER -20/7965 = 0.0025109 or 251 per 100,000
Define prevalence proportion - CORRECT ANSWER -Number of existing cases divided by current
population
Screening discovered 35 women of the 8000 screened had previously been diagnosed with breast cancer
and 20 with no history were diagnosed as a result of screening. What is the prevalence proportion? -
CORRECT ANSWER -55/8000 = 0.006875, or 687.5 per 100,000
When is prevalence useful? - CORRECT ANSWER -Determining chronic illness, planning health
services, determining HCP needs, evaluating treatments
When is incidence useful? - CORRECT ANSWER -When studying cause. It is only affected by
factors related to the risk for developing disease. Influenced by preventative health measures
What is the attack rate? - CORRECT ANSWER -The # of persons exposed to an agent who are sick
What is the case fatality rate? - CORRECT ANSWER -# of deaths from a specific disease in a
given time period
What does the Epidemiological triangle state? - CORRECT ANSWER -All diseases are affected by
an agent, host, and environment. Changes in one element can influence the occurrence of disease
What does the web of causation/causality state? - CORRECT ANSWER -There are a lot of
different causes of disease
, What is the relationship between natural history of disease and levels of prevention? - CORRECT
ANSWER -Prepathogenesis - health promo/disease prevention (primary)
Early pathogenesis - restoration (secondary)
Pathogenesis - rehabilitation (tertiary)
What is the goal of screening? - CORRECT ANSWER -To determine the likelihood that these
individuals will develop the disease
What is included in an effective screening program? - CORRECT ANSWER -REFERRALS for
diagnostic eval for those who screen positive
What is reliability vs validity? - CORRECT ANSWER -Precise vs accurate
How is validity measured? - CORRECT ANSWER -sensitivity and specificity. Sensitivity: true
positives
Specificity: true negatives
What is positive predictive value? - CORRECT ANSWER -Proportion with positive test who
actually have the disease
What is negative predictive value? - CORRECT ANSWER -Proportion with negative test who are
actually disease free
When is high sensitivity needed? - CORRECT ANSWER -when early treatment is important and
when identification of every case is important
When is high specificity needed? - CORRECT ANSWER -When rescreening is impractical and
when it is important to reduce false-positives
What are characteristics of a successful screening program? - CORRECT ANSWER -Valid and
reliable, capable of large group admin, innocuous, high yield, and ethical and effective
Questions and CORRECT Answers
Who is John Snow? - CORRECT ANSWER -The father of epidemiology
He found the source of the 1850's cholera outbreak in London
What is epidemiology? - CORRECT ANSWER -It investigates the distribution of health events in a
population (who, what, when, where, why)
What is descriptive epidemiology? - CORRECT ANSWER -Describes disease according to person,
place, time
What is analytic epidemiology? - CORRECT ANSWER -Describes origins or causes of disease
(how/why)
What is a big indicator of health in a community? - CORRECT ANSWER -Infant mortality rate
How do you calculate rate? - CORRECT ANSWER -Number events divided by population at risk,
then multiplied by 100,000
In 2017 there were 2,813,503 deaths in the U.S.
647,457 of the deaths were caused by heart disease
What was the proportion of deaths attributed to heart disease? - CORRECT ANSWER -0.23, or
23.0%
All cases are called what? - CORRECT ANSWER -Prevalence
New cases are called what? - CORRECT ANSWER -Incidence
Define incident rate - CORRECT ANSWER -rate of development of new cases in a population at
risk
,Define incidence proportion - CORRECT ANSWER -proportion of population at risk that
experiences the event over some period of time
At a hospital screening program for breast cancer, 8000 women were screened.
35 were previously diagnosed with breast cancer
20 with no history of breast cancer were found to have cancer of the breast - CORRECT
ANSWER -20/7965 = 0.0025109 or 251 per 100,000
Define prevalence proportion - CORRECT ANSWER -Number of existing cases divided by current
population
Screening discovered 35 women of the 8000 screened had previously been diagnosed with breast cancer
and 20 with no history were diagnosed as a result of screening. What is the prevalence proportion? -
CORRECT ANSWER -55/8000 = 0.006875, or 687.5 per 100,000
When is prevalence useful? - CORRECT ANSWER -Determining chronic illness, planning health
services, determining HCP needs, evaluating treatments
When is incidence useful? - CORRECT ANSWER -When studying cause. It is only affected by
factors related to the risk for developing disease. Influenced by preventative health measures
What is the attack rate? - CORRECT ANSWER -The # of persons exposed to an agent who are sick
What is the case fatality rate? - CORRECT ANSWER -# of deaths from a specific disease in a
given time period
What does the Epidemiological triangle state? - CORRECT ANSWER -All diseases are affected by
an agent, host, and environment. Changes in one element can influence the occurrence of disease
What does the web of causation/causality state? - CORRECT ANSWER -There are a lot of
different causes of disease
, What is the relationship between natural history of disease and levels of prevention? - CORRECT
ANSWER -Prepathogenesis - health promo/disease prevention (primary)
Early pathogenesis - restoration (secondary)
Pathogenesis - rehabilitation (tertiary)
What is the goal of screening? - CORRECT ANSWER -To determine the likelihood that these
individuals will develop the disease
What is included in an effective screening program? - CORRECT ANSWER -REFERRALS for
diagnostic eval for those who screen positive
What is reliability vs validity? - CORRECT ANSWER -Precise vs accurate
How is validity measured? - CORRECT ANSWER -sensitivity and specificity. Sensitivity: true
positives
Specificity: true negatives
What is positive predictive value? - CORRECT ANSWER -Proportion with positive test who
actually have the disease
What is negative predictive value? - CORRECT ANSWER -Proportion with negative test who are
actually disease free
When is high sensitivity needed? - CORRECT ANSWER -when early treatment is important and
when identification of every case is important
When is high specificity needed? - CORRECT ANSWER -When rescreening is impractical and
when it is important to reduce false-positives
What are characteristics of a successful screening program? - CORRECT ANSWER -Valid and
reliable, capable of large group admin, innocuous, high yield, and ethical and effective
