Biostats 2

Question 1

This statistical test compares differences between means of 2 groups. Requires that a quantitative dependent variable be evaluated in 2 groups that are classified upon a categorical independent variable

Answer 1

T-test

Question 2

Define Relative risk reduction

Answer 2

The proportion of risk reduction attributable to the intervention as compared to a control
RRR= 1-RR or (Event rate of control - Event rate of treatment) / Event rate of control

Question 3

Ratio of the number of people who contract an illness divided by the number of people who are at risk of contracting that illness

Answer 3

Attack rate

Question 4

Formulas for likelihood ratio

Answer 4

\+LR = sensitivity / 1 - specificity
-LR = 1 - sensitivity / specificity

Question 5

Consistency and reproducibility of a test

Answer 5

Precision

Question 6

Closeness of test results to the true values

Answer 6

Accuracy

Question 7

Refers to the ability to correctly identify those with the disease. It rules OUT disease

Answer 7

Sensitivity

Question 8

Represents the ability of the test to correctly identify those without the disease. It rules IN disease

Answer 8

Specificity

Question 9

The probability of two or more independent events occurring together can be calculated by…

Answer 9

Multiplying the individual probabilities of each event

Question 10

Third factor alters the effect; maintains effect but only in one group. There will be a significant difference when stratification is performed

Answer 10

Effect modification