Biostats

Question 1

Sensitivity =

Answer 1

Sensitivity = TP/(TP+FN)

Question 2

Specificity =

Answer 2

Specificity = TN/(TN+FP)

Question 3

The greater the prevalence of a disease, the greater the ___?

Answer 3

PPV

Question 4

The lesser the prevalence of a disease, the greater the ___?

Answer 4

NPV

Question 5

The lesser the prevalence of a disease, the greater the ___?

Answer 5

NPV

Question 6

What is the absolute risk reduction conceptually?

Answer 6

Percentage decrease in the risk of disease/death from a treatment compared with the total number of people in a population

Question 7

What percent is 1 SD?

Answer 7

68%

Question 8

What percent is 2 SD?

Answer 8

95%

Question 9

What percent is 3 SD?

Answer 9

99.7%

Question 10

What is the Mode?

Answer 10

The most frequently appearing value

Question 11

What is the incidence?

Answer 11

New numbers of cases per unit time

Question 12

What is the prevalence?

Answer 12

Total number of cases in a population

Question 13

What does the T-test measure?

Answer 13

2 groups of data

Question 14

What does the ANOVA test measure?

Answer 14

3+ groups of data

Question 15

What does the Chi-Square test measure?

Answer 15

Multiple categories of groups, asks if the groups are related or not

Question 16

Which type of study involves samples sorted into different arms randomly?

Answer 16

Randomized Controlled Trial

Question 17

Which type of study involves observing prospectively over time what happens to groups of patients with a certain exposure or illness?

Answer 17

Cohort Study

“Teens are a risky cohort”

Question 18

Which type of study retrospectively views data looking for the odds of a previous exposure on the development of a rare disease?

Answer 18

Case Control Study

“That was an odd case”

Question 19

Which type of study bias uses hospitalized patients instead of general population?

Answer 19

Berkson bias

Question 20

Which type of study bias occurs when the study subjects know they are being watched?

Answer 20

Hawthorne Effect

Question 21

What is a Type I error?

Answer 21

Rejecting the null when it really is true– eg: saying the new drug works when it really doesn’t

Question 22

What is a Type II error?

Answer 22

Saying the drug does not work when really it does