NUR 503
Mid-Term Study Guide
1. Understand and compare the different measures of morbidity
a. Incidence and prevalence
i. Define
A prevalence rate is the proportion of the population that has a health condition at a
point in time. For example, 70 influenza case-patients in March 2005 reported in County
A.
Incidence rate or person-time rate is a measure of incidence that incorporates time
directly into the denominator. Incidence refers to the occurrence of new cases of
disease or injury in a population over a specified period of time. Although
some epidemiologists use incidence to mean the number of new
cases in a community, others use incidence to mean the number of
new cases per unit of population.
ii. Understand why data are important for measuring risk
iii. Interpret findings
Interpretation involves putting the study findings into perspective, identifying the key
take-home messages, and making sound recommendations. Doing so requires that the
epidemiologist be knowledgeable about the subject matter and the strengths and
weaknesses of the study
iv. Understand the relationship between incidence and prevalence and
impact of each on duration of disease
The two primary measures of morbidity are incidence and prevalence.
• Incidence rates reflect the occurrence of new disease in a population. An incidence
rate describes how quickly disease occurs in a population.
• Prevalence reflects the presence of disease in a population.
v. Calculate incidence rate
Number of new cases of disease or injury during specified period
Time each person was observed, totaled for all persons
vi. Calculate prevalence rate
Number of new cases of disease or injury during specified period
Time each person was observed, totaled for all persons
vii. Relationship between prevalence, incidence, and mortality
Incidence, prevalence, and mortality rates are three frequency measures that are used
to characterize the occurrence of health events in a population.
Incidence rate or person-time rate is a measure of incidence that incorporates time
directly into the denominator. A prevalence rate is the
proportion of the population that has a health condition at a point
in time. A mortality rate is a measure of the frequency of occurrence of
death in a defined population during a specified interval.
viii. Examples of incidence rates and prevalence rates
Prevalence example, 70 influenza case-patients in March 2005
reported in County A,
Incidence for example, 70 new cases of breast cancer per 1,000 women per year. This
measure conveys a sense of the speed with which disease occurs in a population, and
seems to imply that this pattern has occurred and will continue to occur for the
foreseeable future.
2. Surveillance
a. Importance of surveillance
1
Mid-Term Study Guide
1. Understand and compare the different measures of morbidity
a. Incidence and prevalence
i. Define
A prevalence rate is the proportion of the population that has a health condition at a
point in time. For example, 70 influenza case-patients in March 2005 reported in County
A.
Incidence rate or person-time rate is a measure of incidence that incorporates time
directly into the denominator. Incidence refers to the occurrence of new cases of
disease or injury in a population over a specified period of time. Although
some epidemiologists use incidence to mean the number of new
cases in a community, others use incidence to mean the number of
new cases per unit of population.
ii. Understand why data are important for measuring risk
iii. Interpret findings
Interpretation involves putting the study findings into perspective, identifying the key
take-home messages, and making sound recommendations. Doing so requires that the
epidemiologist be knowledgeable about the subject matter and the strengths and
weaknesses of the study
iv. Understand the relationship between incidence and prevalence and
impact of each on duration of disease
The two primary measures of morbidity are incidence and prevalence.
• Incidence rates reflect the occurrence of new disease in a population. An incidence
rate describes how quickly disease occurs in a population.
• Prevalence reflects the presence of disease in a population.
v. Calculate incidence rate
Number of new cases of disease or injury during specified period
Time each person was observed, totaled for all persons
vi. Calculate prevalence rate
Number of new cases of disease or injury during specified period
Time each person was observed, totaled for all persons
vii. Relationship between prevalence, incidence, and mortality
Incidence, prevalence, and mortality rates are three frequency measures that are used
to characterize the occurrence of health events in a population.
Incidence rate or person-time rate is a measure of incidence that incorporates time
directly into the denominator. A prevalence rate is the
proportion of the population that has a health condition at a point
in time. A mortality rate is a measure of the frequency of occurrence of
death in a defined population during a specified interval.
viii. Examples of incidence rates and prevalence rates
Prevalence example, 70 influenza case-patients in March 2005
reported in County A,
Incidence for example, 70 new cases of breast cancer per 1,000 women per year. This
measure conveys a sense of the speed with which disease occurs in a population, and
seems to imply that this pattern has occurred and will continue to occur for the
foreseeable future.
2. Surveillance
a. Importance of surveillance
1
