NR 503 Chamberlain Midterm Exam 2024
Questions With Complete Verified Solution
What is different in a randomized control trial than, for instance, a case-control study (or
a cohort study)? What does it mean to show a causal relationship? - ___________
studies are studies in which patients who already have a specific condition are
compared with people who do not have the condition. The researcher looks back to
identify factors or exposures that might be associated with the illness. They often rely on
medical records and patient recall for data collection. These types of studies are often
less reliable than randomized controlled trials and cohort studies because showing a
statistical relationship does not mean than one factor necessarily caused the other.
_________ are carefully planned experiments that introduce a treatment or exposure to
study its effect on real patients. They include methodologies that reduce the potential for
bias (randomization and blinding) and that allow for comparison between intervention
groups and control (no intervention) groups. A randomized controlled trial is a planned
experiment and can provide sound evidence of cause and effect.
A cause relationship means that a cause is linked to the effect. Such as smoking
causes increased blood pressure and the effects of increased blood pressure is heart
disease.
What is each type of study used for, its purpose, and its outcomes? How are the
outcomes different in each study design? Measured? - Case control studies are studies
in which patients who already have a specific condition are compared with people who
do not have the condition. The researcher looks back to identify factors or exposures
that might be associated with the illness. They often rely on medical records and patient
recall for data collection. These types of studies are often less reliable than randomized
controlled trials and cohort studies because showing a statistical relationship does not
mean than one factor necessarily caused the other.
Cohort studies identify a group of patients who are already taking a particular treatment
or have an exposure, follow them forward over time, and then compare their outcomes
with a similar group that has not been affected by the treatment or exposure being
studied. Cohort studies are observational and not as reliable as randomized controlled
studies, since the two groups may differ in ways other than in the variable under study.
Randomized controlled clinical trials are carefully planned experiments that introduce a
treatment or exposure to study its effect on real patients. They include methodologies
that reduce the potential for bias (randomization and blinding) and that allow for
comparison between intervention groups and control (no intervention) groups. A
randomized controlled trial is a planned experiment and can provide sound evidence of
cause and effect.
, Cross-sectional studies describe the relationship between diseases and other factors at
one point in time in a defined population. Cross sectional studies lack any information
on timing of exposure and outcome relationships and include only prevalent cases.
They are often used for comparing diagnostic tests. Studies that show the efficacy of a
diagnostic test are also called prospective, blind comparison to a gold standard study.
This is a con
What is an intervention group? Where is it found? - The _________ group is the group
in a randomized control trial that receives the treatment.
prospective study - Is a study watches for outcomes, such as the development of a
disease, during the study period and relates this to other factors such as suspected risk
or protection factor(s). The study usually involves taking a cohort of subjects and
watching them over a long period. The outcome of interest should be common;
otherwise, the number of outcomes observed will be too small to be statistically
meaningful (indistinguishable from those that may have arisen by chance). All efforts
should be made to avoid sources of bias such as the loss of individuals to follow up
during the study. Prospective studies usually have fewer potential sources of bias and
confounding than retrospective studies.
Pros- High Quality Data, Future Proof, Strong Validity, Cons- Expensive and time
consuming.
retrospective - study looks backwards and examines exposures to suspected risk or
protection factors in relation to an outcome that is established at the start of the study.
Many valuable case-control studies, such as Lane and Claypon's 1926 investigation of
risk factors for breast cancer, were retrospective investigations. Most sources of error
due to confounding and bias are more common in retrospective studies than in
prospective studies. For this reason, retrospective investigations are often criticized. If
the outcome of interest is uncommon, however, the size of prospective investigation
required to estimate relative risk is often too large to be feasible. In retrospective studies
the odds ratio provides an estimate of relative risk. You should take special care to
avoid sources of bias and confounding in retrospective studies.
Pros: Inexpensive, Quick Results-------Cons- Missing Data (potential bias), definitions
adapted to bias, Unmeasured confounder (Afterthoughts)
Cohort study - A well-defined group of individuals who share a common characteristic or
experience. Participants classified according to exposure status and followed-up over
time to ascertain outcome. Can be used to find multiple outcomes from an exposure.
Appropriate for rare exposures or defined cohorts. Ensures temporality (exposure
occurs before observed outcome). Used when an exposure is rare and outcome is
common (agricultural pesticide and cancer). Used to learn about multiple outcomes
from a single exposure (health effects of a nuclear power plant exposure).
Case-control study - Used to study rare diseases. Used to study multiple exposures that
may have a single outcome. Participants are selected based on outcome status. Case-
subjects have the outcome of interest. Control-subjects do not have the outcome of
Questions With Complete Verified Solution
What is different in a randomized control trial than, for instance, a case-control study (or
a cohort study)? What does it mean to show a causal relationship? - ___________
studies are studies in which patients who already have a specific condition are
compared with people who do not have the condition. The researcher looks back to
identify factors or exposures that might be associated with the illness. They often rely on
medical records and patient recall for data collection. These types of studies are often
less reliable than randomized controlled trials and cohort studies because showing a
statistical relationship does not mean than one factor necessarily caused the other.
_________ are carefully planned experiments that introduce a treatment or exposure to
study its effect on real patients. They include methodologies that reduce the potential for
bias (randomization and blinding) and that allow for comparison between intervention
groups and control (no intervention) groups. A randomized controlled trial is a planned
experiment and can provide sound evidence of cause and effect.
A cause relationship means that a cause is linked to the effect. Such as smoking
causes increased blood pressure and the effects of increased blood pressure is heart
disease.
What is each type of study used for, its purpose, and its outcomes? How are the
outcomes different in each study design? Measured? - Case control studies are studies
in which patients who already have a specific condition are compared with people who
do not have the condition. The researcher looks back to identify factors or exposures
that might be associated with the illness. They often rely on medical records and patient
recall for data collection. These types of studies are often less reliable than randomized
controlled trials and cohort studies because showing a statistical relationship does not
mean than one factor necessarily caused the other.
Cohort studies identify a group of patients who are already taking a particular treatment
or have an exposure, follow them forward over time, and then compare their outcomes
with a similar group that has not been affected by the treatment or exposure being
studied. Cohort studies are observational and not as reliable as randomized controlled
studies, since the two groups may differ in ways other than in the variable under study.
Randomized controlled clinical trials are carefully planned experiments that introduce a
treatment or exposure to study its effect on real patients. They include methodologies
that reduce the potential for bias (randomization and blinding) and that allow for
comparison between intervention groups and control (no intervention) groups. A
randomized controlled trial is a planned experiment and can provide sound evidence of
cause and effect.
, Cross-sectional studies describe the relationship between diseases and other factors at
one point in time in a defined population. Cross sectional studies lack any information
on timing of exposure and outcome relationships and include only prevalent cases.
They are often used for comparing diagnostic tests. Studies that show the efficacy of a
diagnostic test are also called prospective, blind comparison to a gold standard study.
This is a con
What is an intervention group? Where is it found? - The _________ group is the group
in a randomized control trial that receives the treatment.
prospective study - Is a study watches for outcomes, such as the development of a
disease, during the study period and relates this to other factors such as suspected risk
or protection factor(s). The study usually involves taking a cohort of subjects and
watching them over a long period. The outcome of interest should be common;
otherwise, the number of outcomes observed will be too small to be statistically
meaningful (indistinguishable from those that may have arisen by chance). All efforts
should be made to avoid sources of bias such as the loss of individuals to follow up
during the study. Prospective studies usually have fewer potential sources of bias and
confounding than retrospective studies.
Pros- High Quality Data, Future Proof, Strong Validity, Cons- Expensive and time
consuming.
retrospective - study looks backwards and examines exposures to suspected risk or
protection factors in relation to an outcome that is established at the start of the study.
Many valuable case-control studies, such as Lane and Claypon's 1926 investigation of
risk factors for breast cancer, were retrospective investigations. Most sources of error
due to confounding and bias are more common in retrospective studies than in
prospective studies. For this reason, retrospective investigations are often criticized. If
the outcome of interest is uncommon, however, the size of prospective investigation
required to estimate relative risk is often too large to be feasible. In retrospective studies
the odds ratio provides an estimate of relative risk. You should take special care to
avoid sources of bias and confounding in retrospective studies.
Pros: Inexpensive, Quick Results-------Cons- Missing Data (potential bias), definitions
adapted to bias, Unmeasured confounder (Afterthoughts)
Cohort study - A well-defined group of individuals who share a common characteristic or
experience. Participants classified according to exposure status and followed-up over
time to ascertain outcome. Can be used to find multiple outcomes from an exposure.
Appropriate for rare exposures or defined cohorts. Ensures temporality (exposure
occurs before observed outcome). Used when an exposure is rare and outcome is
common (agricultural pesticide and cancer). Used to learn about multiple outcomes
from a single exposure (health effects of a nuclear power plant exposure).
Case-control study - Used to study rare diseases. Used to study multiple exposures that
may have a single outcome. Participants are selected based on outcome status. Case-
subjects have the outcome of interest. Control-subjects do not have the outcome of
