Statistics

Question 1

Gold standard for determining causality

Answer 1

RCTs

Question 2

Prospective study grouped according to exposure status for a risk factor

Answer 2

Cohort study

Question 3

Prospective study subjects randomly assigned to groups and followed

Answer 3

RCT

Question 4

Retrospective study measurements taken after occurence of outcomes grouped by outcome

Answer 4

Case-control

Question 5

Measurements of possible exposure and outcomes made at single point or period in time

Answer 5

Cross-sectional

Question 6

Incorrectly rejecting the null hypothesis

Answer 6

Type I error

Question 7

Incorrectly accepting the null hypothesis

Answer 7

Type II error

Question 8

Number of new cases in a specific population over a specific period of time

Answer 8

Incidence

Question 9

Total cases in a population at a specific point in time

Answer 9

Prevalence

Question 10

Probability of testing positive if you have the disease

Answer 10

Sensitivity

Question 11

Probability of testing negative if you do not have the disease

Answer 11

Specificity

Question 12

Test to determine difference between means of two groups

Answer 12

t-test

Question 13

Test for analyzing to known differences between two groups

Answer 13

z-test

Question 14

Test used to determine whether there is a significant difference between expected and observed frequencies in one or more categories

Answer 14

chi-square

Question 15

Test used to compare means among three or more normally distributed groups

Answer 15

ANOVA

Question 16

Studies reporting positive results are more likely than studies reporting negative results, type of bias

Answer 16

Publication bias

Question 17

Study staff can influence the results of a study; experimenters can interpret results incorrectly because of a tendency to identify information that supports their hypothesis. Blinding helps to ameliorate this type of bias

Answer 17

Observer bias

Question 18

Study participants often have incomplete or skewed recollections of past events. This is particularly a problem in retrospective studies (eg, case-control studies)

Answer 18

Recall bias

Question 19

Study subjects changing behavior because they are aware they are being observed, ie, they are on their best behavior

Answer 19

Hawthorne effect

Question 20

Compares nonparametric data from the same group

Answer 20

Wilcoxon signed-rank test

Question 21

Kaplan-Meier method for an event occurring at a certain point in time

Answer 21

Log-rank test