NUR 345 Exam 2 Study Guide with
Questions and Correct Answers
Epidemiologic Triangle ✅bidirectional arrows because the impact can always move
both ways
Agent ✅factor that causes disease (Ex. E. Coli)
Host ✅refers to the person to animals that harbor the disease-causing agent, may or
may not develop the disease (Ex. Humans)
Environment ✅external conditions that allow the agent to survive and multiple, where
the interaction between host and agent takes place (Ex. Infected beed from cows
interacts with new host after consumption)
Vector ✅Can have fourth component, vector, in the middle of the triangle that points to
all three (Ex. Cows)
Two assumptions about the Epidemiological Triangle ✅disease occurs when an agent
is present in a susceptible host under favorable environment conditions favorable to the
development of the disease
Changes in one component of the triangle can influence whether a disease occurs
This model works best for communicable or infectious disease but not with chronic
disease because the focus is too narrow
Web of causation ✅used to investigate relationships between factors related to the
who, what, where, when, and why
This model is used to study chronic diseases because they have multiple interactions
Ratios in epidemiology ✅rate is calculated by dividing the number of occurrences of a
disease or conditions by the total population potentially affected
Numerator - number of occurrences of an event during a specific period of time
Denominator - total number of populations of interest during the same period of time
K - constant (built in number we can use to make sense of, ex. 1,000 or 100,000)
Mathematical expression of the frequency with which an event occurs in a defined
population during a specific time period, represents the frequency which an event
occurs in a particular population during a specific period of time
Ex.
, Number of UK students positive for COVID-19 in 2020/Total UK student population x
1,000 = 17,000/30,000 x 1,000 = 567 UK students out of 1,000 positive for COVID-19 in
2020
Reliability ✅extent a measuring procedure yields consistent results on repeated
administration of the scale
Ex: Exact same results every year
Validity ✅degree a measuring procedure accurately reflects or assesses or captures
the specific concept that the researcher is attempting to measure
Sensitivity ✅ability of a test to correctly identify those with the disease (true positive
rate)
If you have the disease or condition, you would have a true positive
Ex. If you are pregnant, a pregnancy test has good sensitivity if it can correct produce a
positive result
Specificity ✅ability of a test to correctly identify those without the disease or condition
If you don't have a disease, you would want a true negative
Ex. If you are not pregnant, a pregnancy test has good specificity if it can correctly
produce a negative result
Risk ✅refers to the chance or probability that disease, deterioration of disease status,
or injury will occur
Ex. Non-smokers who are exposed to secondhand smoke at hoe or at work increase
their risk fo developing lung cancer by 20-30%
Ex. Sexually active individuals who do not use contraception have an 86% chance of
getting pregnant in a year
Risk factors ✅individual attributes or characteristics of the physical and social
environment that increases the likelihood that someone will engage in potentially
harmful behaviors or suffer negative health outcomes
Ex. Negative attributes among peers about condom use is a risk factor for unprotected
sex
Ex. Poor infrastructures for pedestrian safety is a risk factor for road traffic injuries
Risk behaviors ✅refers to a behavioral risk factor that increases the likelihood of
disease, deterioration of disease status or injury now or in the future
Ex. Excessive alcohol use
Questions and Correct Answers
Epidemiologic Triangle ✅bidirectional arrows because the impact can always move
both ways
Agent ✅factor that causes disease (Ex. E. Coli)
Host ✅refers to the person to animals that harbor the disease-causing agent, may or
may not develop the disease (Ex. Humans)
Environment ✅external conditions that allow the agent to survive and multiple, where
the interaction between host and agent takes place (Ex. Infected beed from cows
interacts with new host after consumption)
Vector ✅Can have fourth component, vector, in the middle of the triangle that points to
all three (Ex. Cows)
Two assumptions about the Epidemiological Triangle ✅disease occurs when an agent
is present in a susceptible host under favorable environment conditions favorable to the
development of the disease
Changes in one component of the triangle can influence whether a disease occurs
This model works best for communicable or infectious disease but not with chronic
disease because the focus is too narrow
Web of causation ✅used to investigate relationships between factors related to the
who, what, where, when, and why
This model is used to study chronic diseases because they have multiple interactions
Ratios in epidemiology ✅rate is calculated by dividing the number of occurrences of a
disease or conditions by the total population potentially affected
Numerator - number of occurrences of an event during a specific period of time
Denominator - total number of populations of interest during the same period of time
K - constant (built in number we can use to make sense of, ex. 1,000 or 100,000)
Mathematical expression of the frequency with which an event occurs in a defined
population during a specific time period, represents the frequency which an event
occurs in a particular population during a specific period of time
Ex.
, Number of UK students positive for COVID-19 in 2020/Total UK student population x
1,000 = 17,000/30,000 x 1,000 = 567 UK students out of 1,000 positive for COVID-19 in
2020
Reliability ✅extent a measuring procedure yields consistent results on repeated
administration of the scale
Ex: Exact same results every year
Validity ✅degree a measuring procedure accurately reflects or assesses or captures
the specific concept that the researcher is attempting to measure
Sensitivity ✅ability of a test to correctly identify those with the disease (true positive
rate)
If you have the disease or condition, you would have a true positive
Ex. If you are pregnant, a pregnancy test has good sensitivity if it can correct produce a
positive result
Specificity ✅ability of a test to correctly identify those without the disease or condition
If you don't have a disease, you would want a true negative
Ex. If you are not pregnant, a pregnancy test has good specificity if it can correctly
produce a negative result
Risk ✅refers to the chance or probability that disease, deterioration of disease status,
or injury will occur
Ex. Non-smokers who are exposed to secondhand smoke at hoe or at work increase
their risk fo developing lung cancer by 20-30%
Ex. Sexually active individuals who do not use contraception have an 86% chance of
getting pregnant in a year
Risk factors ✅individual attributes or characteristics of the physical and social
environment that increases the likelihood that someone will engage in potentially
harmful behaviors or suffer negative health outcomes
Ex. Negative attributes among peers about condom use is a risk factor for unprotected
sex
Ex. Poor infrastructures for pedestrian safety is a risk factor for road traffic injuries
Risk behaviors ✅refers to a behavioral risk factor that increases the likelihood of
disease, deterioration of disease status or injury now or in the future
Ex. Excessive alcohol use
