©JUSTTRACY EXAM SOLUTIONS
12/11/2024 4:30PM
Epidemiology Midterm 2 Updated Exam
Questions And Answers
The high degree if validity in which type of study stems mainly from the investigator's ability
to randomize subjects to either the treatment group or the comparison group and thereby
control for distortions produced by confounding variables? - answers✔✔Experimental Study
Which type of observational study examines one or more health effects/outcomes of exposure
to a single agent? - answers✔✔Cohort Study
The exposed group can also be referred to as which of the following? - answers✔✔Index
Group
Which of the following is a method of sampling a population in which researchers identify
and enroll cases of disease and a sample of the source population that gave rise to the cases? -
answers✔✔Case-control Study
The main disadvantage of using which type of controls is the difficulty in determining
appropriate illnesses for inclusion? - answers✔✔Hospital and clinic controls
Which type of studies typically take a snapshot of a population at a single point in time and
therefore usually measures the disease prevalence, exposure prevalence, or relationship
between the two? - answers✔✔Cross Sectional Study
Which type of study evaluates an association using the population rather than the individual
as the unit of analysis? - answers✔✔Ecological Study
Observational studies take advantage of the fact that people expose themselves to noxious or
healthy substances through their personal habits. - answers✔✔True
, ©JUSTTRACY EXAM SOLUTIONS
12/11/2024 4:30PM
Consider a cohort of 2,000 people, of whom 800 are smokers and 1,200 are non-smokers.
The entire cohort is observed for 20 years, and 100 participants develop lung cancer, of who
90 are smokers and 10 are not.
What is the incidence rate of lung cancer for non-smokers in this cohort per 1,000? -
answers✔✔8.3 per 1,000
Incidence Rate= (# of NEW cases during time period)/ (total person time of observation in
population at risk)
(10 nonsmokers with lung cancer*20 years)/(1200 nonsmokers* 20 years)= 0.00833
*1000=8.3 per 1000
Consider a cohort of 2,000 people, of whom 800 are smokers and 1,200 are non-smokers.
The entire cohort is observed for 20 years, and 100 participants develop lung cancer, of who
90 are smokers and 10 are not.
Which is the correct interpretation for relative risk? - answers✔✔Smokers are "x" times as
likely to develop lung cancer as compared to non-smokers
A study was conducted in which 5,763 British children were recruited who had either
received or not received the measles-mumps-rubella vaccination. These children were then
followed over a 10 year period to see if there was any development of a pervasive
development disorder (e.g. autism and Asperger's syndrome). This is an example of what
type of study? - answers✔✔Cohort
Consider a cohort of 2,000 people, of whom 800 are smokers and 1,200 are non-smokers.
The entire cohort is observed for 20 years, and 100 participants develop lung cancer, of who
90 are smokers and 10 are not.
What is the incidence rate of lung cancer for smokers in this cohort per 1,000? -
answers✔✔112.5 per 1,000
Incidence Rate=Incidence Rate= (# of NEW cases during time period)/ (total person time of
observation in population at risk)
IR= (90* 20)/ (800* 20)= 0.1125 *1000= 112.5 per 1000
12/11/2024 4:30PM
Epidemiology Midterm 2 Updated Exam
Questions And Answers
The high degree if validity in which type of study stems mainly from the investigator's ability
to randomize subjects to either the treatment group or the comparison group and thereby
control for distortions produced by confounding variables? - answers✔✔Experimental Study
Which type of observational study examines one or more health effects/outcomes of exposure
to a single agent? - answers✔✔Cohort Study
The exposed group can also be referred to as which of the following? - answers✔✔Index
Group
Which of the following is a method of sampling a population in which researchers identify
and enroll cases of disease and a sample of the source population that gave rise to the cases? -
answers✔✔Case-control Study
The main disadvantage of using which type of controls is the difficulty in determining
appropriate illnesses for inclusion? - answers✔✔Hospital and clinic controls
Which type of studies typically take a snapshot of a population at a single point in time and
therefore usually measures the disease prevalence, exposure prevalence, or relationship
between the two? - answers✔✔Cross Sectional Study
Which type of study evaluates an association using the population rather than the individual
as the unit of analysis? - answers✔✔Ecological Study
Observational studies take advantage of the fact that people expose themselves to noxious or
healthy substances through their personal habits. - answers✔✔True
, ©JUSTTRACY EXAM SOLUTIONS
12/11/2024 4:30PM
Consider a cohort of 2,000 people, of whom 800 are smokers and 1,200 are non-smokers.
The entire cohort is observed for 20 years, and 100 participants develop lung cancer, of who
90 are smokers and 10 are not.
What is the incidence rate of lung cancer for non-smokers in this cohort per 1,000? -
answers✔✔8.3 per 1,000
Incidence Rate= (# of NEW cases during time period)/ (total person time of observation in
population at risk)
(10 nonsmokers with lung cancer*20 years)/(1200 nonsmokers* 20 years)= 0.00833
*1000=8.3 per 1000
Consider a cohort of 2,000 people, of whom 800 are smokers and 1,200 are non-smokers.
The entire cohort is observed for 20 years, and 100 participants develop lung cancer, of who
90 are smokers and 10 are not.
Which is the correct interpretation for relative risk? - answers✔✔Smokers are "x" times as
likely to develop lung cancer as compared to non-smokers
A study was conducted in which 5,763 British children were recruited who had either
received or not received the measles-mumps-rubella vaccination. These children were then
followed over a 10 year period to see if there was any development of a pervasive
development disorder (e.g. autism and Asperger's syndrome). This is an example of what
type of study? - answers✔✔Cohort
Consider a cohort of 2,000 people, of whom 800 are smokers and 1,200 are non-smokers.
The entire cohort is observed for 20 years, and 100 participants develop lung cancer, of who
90 are smokers and 10 are not.
What is the incidence rate of lung cancer for smokers in this cohort per 1,000? -
answers✔✔112.5 per 1,000
Incidence Rate=Incidence Rate= (# of NEW cases during time period)/ (total person time of
observation in population at risk)
IR= (90* 20)/ (800* 20)= 0.1125 *1000= 112.5 per 1000
