Midterm Exam Review: NR 503/ NR503 (Latest 2023/ 2024 Update) Epidemiology Exam Review |Complete Guide with Verified Answers -Chamberlain
QUESTION
Wh... [Show More] at is each type of study used for, its purpose, and its outcomes? How are the outcomes different in each study design? Measured?
Answer:
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 controlled trial that looks at patients with varying degrees of an illness and administers both diagnostic tests — the test under investigation and the "gold standard" test — to all of the patients in the study group. The sensitivity and specificity of the new test are compared to that of the gold standard to determine potential usefulness.
QUESTION
What is an intervention group? Where is it found?
Answer:
The _________ group is the group in a randomized control trial that receives the treatment.
QUESTION
prospective study
Answer:
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.
QUESTION
retrospective
Answer:
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)
QUESTION
Cohort study
Answer:
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).
QUESTION
Case-control study
Answer:
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 interest. Used when the outcome of interest is rare, multiple exposures may have a single outcome, and funding or time is limited.
QUESTION
Randomized Control Trial
Answer:
is a type of scientific (often medical) experiment which aims to reduce bias when testing a new treatment. The people participating in the trial are randomly allocated to either the group receiving the treatment under investigation or to a group receiving standard treatment (or placebo treatment) as the control. Randomization minimizes selection bias and the different comparison groups allow the researchers to determine any effects of the treatment when compared with the no treatment (control) group, while other variables are kept constant. The RCT is often considered the gold standard for a clinical trial. RCTs are often used to test the efficacy or effectiveness of various types of medical intervention and may provide information about adverse effects, such as drug reactions. Random assignment of intervention is done after subjects have been assessed for eligibility and recruited, but before the intervention to be studied begins
QUESTION
cross-sectional study
Answer:
To learn about the characteristics of a population at one point in time like a snapshot (photo). No comparison group. All members of a small, defined group or a sample from a large group. Produces estimates of the prevalence of the population characteristic of interest.Example is measuring the magnitude and patterns of violence among pregnant women. Used to:
1. Estimate prevalence of a health condition or prevalence of a behavior, risk factor, or potential for disease
2. To learn about characteristics such as knowledge, attitude and practices of individuals
in a population
3. To monitor trends over time with serial cross-sectional studies
QUESTION
What is meant by "scientific misconduct"?
Answer:
is the violation of the standard codes of scholarly conduct and ethical behavior in the publication of professional scientific research. Its an action that willfully compromises the integrity of scientific research, such as plagiarism or the falsification or fabrication of data. It includes gift authorship, data fabrication and falsification, plagiarism, and conflict of interest.
QUESTION
Random error
Answer:
measurements tend to be too high or too low in equal amounts do to random factors. And are less serious than bias. They can occur from an unpredictable change in an instrument used for collecting data.
QUESTION
Systemic error [Show Less]
