PE 3 Flashcards
What is the first step in research projects involving humans?
Composing a clear and detailed definition of the study population.
What is the ‘population of interest’ in a study?
The group of people or entities that the study is focusing on.
What are some limits for individuals in the population of interest?
- Where they live
- Their race/ethnicity
- How old they are
- Their gender
What is the ‘target population’?
A specific group of people or entities that can take part in a study.
What is a ‘sampling frame’?
The set of units from which the sample is drawn, operationalized representation of the target population.
Why is it important for the sampling frame to contain an adequate number of units?
To enable the collection of an entire information set, which is vital for study accuracy.
What is the purpose of probability sampling methods?
To ensure equal chances of selection through random selection.
What is simple random sampling?
A method where every member of a group has the same chance of being chosen.
What does stratified random sampling involve?
Dividing the population into subgroups based on characteristics and selecting samples from each stratum proportionally.
What is cluster sampling?
A sampling method where the population is split into smaller groups, and a sample is taken from these clusters.
What is single-stage cluster sampling?
Each unit of selected clusters is picked as a sample.
What distinguishes double-stage cluster sampling?
Data is collected from a random subsample of individual units within selected clusters.
What is multi-stage cluster sampling?
Sampling method that involves multiple sampling steps to gather enough samples.
What is two-phase sampling?
A method where a sample is first selected for auxiliary information and then a second sample is selected for the variable of interest.
What is convenience sampling?
A method where the researcher selects individuals who are most convenient to contact.
What is purposive sampling?
Choosing individuals purposefully based on specific traits or qualities.
What is quota sampling?
Dividing individuals according to criteria and setting goals for how many from each group to include.
What is snowball sampling?
Participants are asked to refer others they know to participate in the study.
What is volunteer sampling?
Individuals who willingly participate in a study are selected.
What five variables should be considered when calculating sample size for cohort studies?
- Alpha (type I error)
- Beta (type II error)
- The minimum effect size
- The expected incidence of the outcome in the unexposed group
- The number of unexposed control subjects per exposed subject
What is alpha (α) in the context of sample size calculations?
The probability of concluding there is a difference between groups when no difference exists (type I error).
What does beta (β) represent in sample size calculations?
The probability of concluding there is no difference between groups when a difference does exist (type II error).
What is the minimum effect size in cohort studies expressed as?
Relative risk.
What is the expected incidence of the outcome of interest in the unexposed control group?
The occurrence rate of the outcome in the control group that is not exposed.
What is the significance of having equal numbers of exposed and unexposed subjects?
It provides the most statistical power for the study.
What is a key distinction between case-control and cohort studies?
Case-control studies select subjects based on the presence or absence of the disease, while cohort studies select based on exposure.
What is the expected prevalence of exposure control in a case-control study?
It refers to the prevalence of exposure in the un-diseased control group.
What is an example of a study that utilized a case series?
The Phase IV post-marketing study for prazosin involving 10,000 newly exposed subjects.
