Study Design
A study design where the groups are defined by the presence or absence of an exposure.
What is a cohort study?
The extent that a measure approximates the true value
What is validity?
This reduction is the actual reduction in risk in exposed compared with unexposed
What is an Absolute Risk Ratio?
This type of error is commonly called a false positive
What is a Type 1 error?
These are the 5 steps of the systemic approach
What are Ask, Acquire, Appraise, Apply, Assess?
One is able to study multiple exposures that may affect the risk of one outcome.
What is an advantage of a case control study?
An outside factor that is associated with an outcome but has no effect on the exposure.
What is a confounding variable?
This is the number of patients who need to be exposed, on average, to prevent 1 outcome event
What is Number Needed to Treat / NTT?
These variables affect power
What are sample size, effect size, and variability?
This step of the systemic approach classifies the issue/request and clarify information
What is Ask?
The reason a “washout” period is necessary in a crossover study.
What is to allow the patient’s condition to return to baseline between the two study periods?
Type of validity that describes how applicable study results are to other patients.
What is external validity?
This ratio is a frequency of its occurrence to frequency of its nonoccurrence
What is an odds value
This variable is the pre-defined acceptable probability of a false negative
What is Beta (β)?
These three types of questions are used during the ASK step in the system approach
What are background, foreground, and clarifying questions?
These are reasons why a concurrent parallel control arm is the “gold standard”.
What are enrollment enables randomization and simultaneous treatment enables blinding?
The two major threats to internal validity.
What is Systematic error (bias) and Random Error?
We can make this conclusion occurs when the Odds Ratio is greater than 1
What is cases are more likely to have been exposed?
If we had a p-value = 0.04 we can make this conclusion about the null hypothesis
What is reject the null hypothesis
These resources should be avoided when you have a background question
What are citation databases (Pubmed, Embase)?
A study design where we examine the correlation between an individual’s annual salary and their hbA1C at a specific point in time.
What is an example of a cross-sectional study?
Types of validity critical in evaluating both observational studies AND experimental trials.
What is internal AND external validity?
This type of ratio cannot be used in case-control studies
What is Risk Ratio?
We can make this conclusion about a subgroup that contains the value 1 and crosses the margin of inferiority on a forest plot
What is not non-inferiority?
This is the reason for needing both background and foreground questions to treat patients
What is level of experience with conditions varies among situations?