Stats

Question 1

Which measure of central tendency is appropriate for skewed data?

Answer 1

Median

Question 2

Which type of variable has groups with no order?

Answer 2

Nominal (e.g. blood type)

Question 3

Which measure of central tendency can be used for nominal data?

Answer 3

Mode

Question 4

Which measure of central tendency can be used for ordinal data?

Answer 4

Median (example of ordinal data- NYHA classes)

Question 5

What kind of data is temperature?

Answer 5

Interval

Question 6

What kind of data is serum creatinine?

Answer 6

Ratio

Question 7

What kind of test is used for time to event data of discrete variables without confounders?

Answer 7

Kaplan Meier or (cox) proportional hazards model

Question 8

How do you calculate the alpha?

Answer 8

1 - confidence interval

Question 9

What does the alpha mean?

Answer 9

Probability of a false positive test

Question 10

What is beta?

Answer 10

The probability of a false negative test

Question 11

What is type 1 error?

Answer 11

False positive

Question 12

What is type 2 error?

Answer 12

False Negative

Question 13

How do you calculate power?

Answer 13

1-beta

Question 14

What is power?

Answer 14

The probability to detect a difference when a difference exists

Question 15

the mean difference between groups has a 95% CI of minus 1.32 to 1.95. Are they different?

Answer 15

No

Question 16

How do you calculate relative risk reduction?

Answer 16

[% outcomes in treatment-% outcomes in control] / % outcomes in control

Question 17

How do you calculate the number needed to treat?

Answer 17

1/[% Outcomes in treatment - % outcomes in control]

Question 18

How do you calculate relative risk reduction?

Answer 18

% Outcomes in Treatment - % Outcomes in Control/ % Outcomes in Control