EBM6: Study Interpretation Flashcards Preview

Foundations Part II > EBM6: Study Interpretation > Flashcards

Flashcards in EBM6: Study Interpretation Deck (17):
1

How does study size impact random error

Random error goes down as the study size or the sample size increases

2

What happens to systematic error with study size

It stays the same, doesnt get impacted by the size

3

Types of systematic error

1. Selection bias
2. Information bias
3. Confounding bias

4

How is selection biases introduced

Subjects who make into the study or the selective losses of the subjects

5

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)

6

Does intention to treat analysis help with loss of subjectives due to selective bias

No

7

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

8

What is information bias also called

Misclassification

9

What are the types of information bias

Recall bias and interviewer bias.

Know the difference between the 2

10

What are the reasons for misclassification

There are 2, Miclasify either the disease or the exposure

11

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

12

How do you address confounding

In the study design phase or in the analysis phase using stratified analysis

13

What other type of bias is there

Medical surveliance bias, medical condition of one disease influences the outcome of a study of another disease

14

Berkson's bias

Using people from hospitals

15

What is hawthorn effect

You act differently when you are being observed

16

What is the difference between association or causality

Association doesnt have any causality

Causation is usually multifactorial

17

How do you determine causality

1. Strength of association
2. Consistency
3. Specificity - single effect
4. Temprality - causes precedes effect
5. Biological gradient
6. Biological plausibility
7. Coherence
8. Experiment
9. Analogy