EBM6: Study Interpretation Flashcards
How does study size impact random error
Random error goes down as the study size or the sample size increases
What happens to systematic error with study size
It stays the same, doesnt get impacted by the size
Types of systematic error
- Selection bias
- Information bias
- Confounding bias
How is selection biases introduced
Subjects who make into the study or the selective losses of the subjects
What is intention to treat analysis
Analyse what you randomize (people lost in the course of the study have their data not considered from the very beginning)
Does intention to treat analysis help with loss of subjectives due to selective bias
No
What is information bias
Faulty measurement of data or erroneous data due to some other reason.
It can result from error in the design or conduct of the study
What is information bias also called
Misclassification
What are the types of information bias
Recall bias and interviewer bias.
Know the difference between the 2
What are the reasons for misclassification
There are 2, Miclasify either the disease or the exposure
What is differential and non differential misclasification
Non differential is when you make the same mistake in the classification of the disease whereas in differential you only make the mistake once and dont repeat the mistake throughout the study
How do you address confounding
In the study design phase or in the analysis phase using stratified analysis
What other type of bias is there
Medical surveliance bias, medical condition of one disease influences the outcome of a study of another disease
Berkson’s bias
Using people from hospitals
What is hawthorn effect
You act differently when you are being observed
