Critically Reviewing the Study Samples Flashcards
What questions should you have regarding the study sample?
Who was the population being test?
How was the sample selected?
Does the sample fairly represent the target population?
What is a population?
An aggregate of persons who meet a specific criteria
What is a sample?
Reference group for estimating characteristics or drawing conclusions about the larger population
Small subset of people
If sampled properly, can findings from a sample be generalized to a larger population?
Yes
What is generalizability dependent on?
The representative sample
A sample that reflects the relevant characteristics and variables of the population
An issue of external validity
What is sampling error?
The difference between the sample and the population
This can be influences by sample size and sample bias
What should you consider about sample size?
Watch out for small samples (smaller than 20)
What should you consider about sample bias?
Strict or narrow inclusion/exclusion criteria
Selection/recruitment methods
Participation bias
Do inclusion and exclusion criteria operationally define your target population?
Yes
And it also defines the group to whom you can generalize your results
Do we need to consider if the individuals who decided to participate in the study differ from those who decided to not participate?
Yes, need to consider if there is a reason for this and what could that mean
What should we consider when we evaluate the study sample and if they are representative of the entire population?
Number of sites: multiple sites better than single site
Geographical locations: multiple locations better than single location
Settings: a setting that reflects where most patients receive care is better than others (eg, academic hospital settings, laboratory settings, etc.)
