Epidemiology Midterm 2 Exam Questions And
Answers 100% Correct
What type of study has high degree if validity mainly because the investigator is able to
randomize subjects to either the treatment group or the comparison group and thereby
control for distortions produced by confounding variables? - ANSWER Experimental
Study
Which of the following is an example of an observational study that examines one or
more health effects/outcomes of exposure to a single agent? - ANSWER Cohort Study
The exposed group can also be referred to as which of the following? - ANSWER 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? - ANSWER Casecontrol Study
What is the major drawback to using what type of controls, in that it is difficult to
determine appropriate illnesses for inclusion? - ANSWER Hospital and clinic controls
What type of studies generally take a snapshot of a population at one point in time and
therefore usually measures the disease prevalence, exposure prevalence, or the
relationship between the two? - ANSWER Cross Sectional Study
What type of study assesses an association with the population rather than the
individual as the unit of analysis? - ANSWER Ecological Study
Observational studies are based upon the fact that people expose themselves to
noxious or healthy substances through their personal habits. - ANSWER True
, Now let's consider a cohort of 2,000 people of whom 800 are smokers and 1,200 are
non-smokers. The entire cohort is followed 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 nonsmokers in this cohort per 1,000? -
ANSWER 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
Imagine for a cohort of 2,000 people, of which 800 are smokers and 1,200 nonsmokers.
The entire cohort is followed up for a period of 20 years, in which 100 participants
develop lung cancer, of which 90 are smokers and the rest 10 who are not.
Which of the following is the correct interpretation for relative risk? - ANSWER Smokers
are "x" times as likely to develop lung cancer as compared to nonsmokers.
A total of 5,763 British children who had or had not had the measles-mumps-rubella
vaccination were recruited into a study. The children were followed over a 10- year
period to identify whether a pervasive development disorder, for example, autism and
Asperger's syndrome developed. This is an example of what type of study? - ANSWER
Cohort
Suppose there is a cohort of 2,000 persons out of which 800 are smokers and 1,200
nonsmokers. The total cohort is followed up for 20 years and during this period, 100
participants develop lung cancer out of which 90 are smokers and 10 nonsmokers.
What is the incidence rate of lung cancer for smokers in this cohort per 1,000? -
ANSWER 112.5 per 1,000
Incidence Rate=Incidence Rate= (# of NEW cases during time period)/ (total person time
of observation in population at risk)
Answers 100% Correct
What type of study has high degree if validity mainly because the investigator is able to
randomize subjects to either the treatment group or the comparison group and thereby
control for distortions produced by confounding variables? - ANSWER Experimental
Study
Which of the following is an example of an observational study that examines one or
more health effects/outcomes of exposure to a single agent? - ANSWER Cohort Study
The exposed group can also be referred to as which of the following? - ANSWER 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? - ANSWER Casecontrol Study
What is the major drawback to using what type of controls, in that it is difficult to
determine appropriate illnesses for inclusion? - ANSWER Hospital and clinic controls
What type of studies generally take a snapshot of a population at one point in time and
therefore usually measures the disease prevalence, exposure prevalence, or the
relationship between the two? - ANSWER Cross Sectional Study
What type of study assesses an association with the population rather than the
individual as the unit of analysis? - ANSWER Ecological Study
Observational studies are based upon the fact that people expose themselves to
noxious or healthy substances through their personal habits. - ANSWER True
, Now let's consider a cohort of 2,000 people of whom 800 are smokers and 1,200 are
non-smokers. The entire cohort is followed 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 nonsmokers in this cohort per 1,000? -
ANSWER 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
Imagine for a cohort of 2,000 people, of which 800 are smokers and 1,200 nonsmokers.
The entire cohort is followed up for a period of 20 years, in which 100 participants
develop lung cancer, of which 90 are smokers and the rest 10 who are not.
Which of the following is the correct interpretation for relative risk? - ANSWER Smokers
are "x" times as likely to develop lung cancer as compared to nonsmokers.
A total of 5,763 British children who had or had not had the measles-mumps-rubella
vaccination were recruited into a study. The children were followed over a 10- year
period to identify whether a pervasive development disorder, for example, autism and
Asperger's syndrome developed. This is an example of what type of study? - ANSWER
Cohort
Suppose there is a cohort of 2,000 persons out of which 800 are smokers and 1,200
nonsmokers. The total cohort is followed up for 20 years and during this period, 100
participants develop lung cancer out of which 90 are smokers and 10 nonsmokers.
What is the incidence rate of lung cancer for smokers in this cohort per 1,000? -
ANSWER 112.5 per 1,000
Incidence Rate=Incidence Rate= (# of NEW cases during time period)/ (total person time
of observation in population at risk)
