Sem 2 (1)

Question 1

Classifications of statistics - define them

Answer 1

Descriptive (describing data)

Inferential (analysing data to enable conclusions to be drawn from data)

Question 2

What is a statistic?

Answer 2

Collection, presentation, description and analysis of data which are measurable in numerical forms

Question 3

Evidence based medicine definition

Answer 3

Conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients
Integrating individual clinical expertise with the best available external clinical evidence from systematic research

Question 4

Epidemiology

Answer 4

Study of distribution and determinants of health-related states or events in specified
populations and the application of this study to the control of health problems

Question 5

Methods to carry out epidemiological studies
What are they used to study?

Answer 5

Surveillance and descriptive studies (distribution)

Analytical studies (determinants)

Question 6

Surveillance and descriptive studies
How many groups?
Hypothesis?
How does it end?

Answer 6

One group

No explicit hypothesis

Development of possible hypothesis regarding cause and effect relationship

Question 7

Analytical studies
How many groups?
Hypothesis?
How does it end?

Answer 7

two or more - for comparison

definite hypothesis regarding an exposure possibly causing an outcome

reject or accept hypothesis at end

Question 8

What does a sample population require (3)

Answer 8

Representative
Unbiased - on target (dart board)
Precise - well grouped (dart board)

Question 9

Larger studies
What are they?
What does this not equate to?

Answer 9

More precise

Does not equate to less bias

Question 10

What are the two types of validity a study must have?

Answer 10

Internal
External

Question 11

Internal validity

Answer 11

whether the study design, conduct, and analysis answer the research questions without bias

Question 12

External validity

Answer 12

Degree to which conclusions/results can be applied to the population of interest

Question 13

What does it mean if the study is internally valid?

Answer 13

the conclusions should be correct within the circumstances of the study

Question 14

Types of error (2)

Answer 14

Chance - random
Bias - systematic

Question 15

Chance error
What causes it?
How does it reduce?

Answer 15

Sampling variation (people selected)

As sampling size increases

Question 16

Bias error
How is it quantified?
How is it effected if sample size increases?

Answer 16

the difference between the true value and expected value

Doesn’t reduce

Question 17

What are the two types of bias error?

Answer 17

Selection bias

Information bias

Question 18

Selection bias
What affects it? (3)

Answer 18

Study sample (external validity)
Group selection within a study (internal validity)
Healthy worker effect

Question 19

External validity of selection bias
What is it

Answer 19

Study sample
Sample isn’t representative of the entire population of interest

Question 20

Internal validity of selection bias
What is it

Answer 20

Group selection within a study
Groups within a study may not be comparable

Question 21

Healthy worker effect

Answer 21

workers usually exhibit lower overall mortality than general population

Question 22

Information bias
What affects it? (4)

Answer 22

Recall error
Observer/interviewer error
Measurement error
Misclassification

Question 23

Recall error
What type of bias?
What is it?

Answer 23

Information
difference in recollection from study participants re event or experiences from the pass

Question 24

Observer/interviewer error
What type of bias?
What is it?

Answer 24

Information
study observer or interview has preconceived expectations or knowledge that influences result

Question 25

Misclassification error
What type of bias?
What is it?

Answer 25

Information
participants put in the wrong group e.g. diseased when aren’t