Stats

Question 0

Data that is ordered or ranked categories (stages, functional status, etc)?

Answer 0

Ordinal

Question 1

Data that is categorical (male/female, alive/dead, etc)?

Answer 1

Nominal

Question 2

Data that is continuous (equal distance between values)?

Answer 2

Interval

Question 3

Central tendency for interval (continuous) data?

Answer 3

Mean (average)

Question 4

Central tendency for ordinal data?

Answer 4

Median (1/2 subjects above and 1/2 below)

Question 5

Central tendency for nominal data?

Answer 5

Mode (most frequently occurring category)

Question 6

Parametric or Non-parametric?
Continuous Data
Normal distribution or n>30

Answer 6

Parametric Statistics

normal distribution

Question 7

Parametric or Non-parametric?
Ordinal or Discrete Data or n<30
Tests have less power

Answer 7

Non-parametric Data

Question 8

Choose a Test

2 groups Continuous (parametric) data

Answer 8

Student’s t-test

Question 9

Choose a Test

2 groups Nonparametric data

Answer 9

Mann-Whitney U or

Wilcoxon rank sum

Question 10

Choose a Test

2 groups Categorical (Nominal)

Answer 10

Chi-square

Fisher’s Exact Test

Question 11

Choose a Test

3+ groups Continuous (parametric) data

Answer 11

One-way ANOVA

Question 12

Choose a Test

3+ groups Nonparametric data

Answer 12

Kruskal Wallis

Question 13

Choose a Test

3+ groups Categorical (Nominal) data

Answer 13

Chi-square test

Question 14

Choose a Test

Predict a variable from another with continuous (parametric) data

Answer 14

Linear Regression

Question 15

Choose a Test

Predict a variable from another with categorical (nominal) data

Answer 15

Logistic Regression

Question 16

Choose a Test

2 paired groups - continuous (parametric) data

Answer 16

Paired t-test

Question 17

Choose a Test

2 paired groups - nonparametric data

Answer 17

Wilcoxon signed rank

Question 18

Choose a Test

2 paired groups - categorical (nominal) data

Answer 18

McNemar’s

Question 19

Choose a Test

Association btwn 2 variables - continuous (parametric) data

Answer 19

Pearson correlation

Range -1 to 1 0=no corr

Question 20

Choose a Test

Association btwn 2 variables - nonparametric data

Answer 20

Spearman correlation

Range -1 to 1 0=no corr

Question 21

Choose a Test

Association btwn 2 variables - categorical (nominal) data

Answer 21

Chi-square

Question 22

This type of analysis analyzes “time to event” (death, recurrence, etc)?

Answer 22

Survival Analysis

1group - Kaplan Meier Survival Curve

2groups - Log-rank test

Predict variable from another -
Cox proportional hazards regression
(Hazard ratios)

Question 23

What measures the chance that the difference in a study occurred by chance?

Answer 23

p Value

Question 24

What measures the probability that the difference between two values could have occurred by chance?
(Type 1 error - false-positive conclusion)

Answer 24

p Value

Question 25

Risk of disease in exposed
———————————— = ?
Risk of disease in unexposed

Answer 25

Relative risk

Cohort studies and RCTs

Question 26

Odds of disease in exposed
———————————— = ?
Odds of disease in unexposed

Answer 26

Odds ratio

Will overestimate RR with common events

Question 27

With regard to relative risk and confidence interval, a value of 1 indicates?

Answer 27

No effect

> 1 - increased risk/odds
<0.05

Question 28

What is a Type 1 error?

Answer 28

False-positive: detect a difference when no exists

Probability of incorrectly rejecting the null hypothesis

Question 29

What is a Type II or beta error?

Answer 29

False-negative.

Probability of not detecting a significant difference when one exists

Question 30

Power is?

Answer 30

1-beta

Probability of detecting a difference when one exists

Question 31

What do you need to calculate sample size?

Answer 31

1 frequency of X in group A&B
2 alpha (ie 0.05)
3 power (ie 0.8 or 1-beta)
4 ratio of A to B

Can calculate any one of 5 from the other 4

Question 32

Which varies based on prevalence of a disease, sensitivity/specificity or positive/negative predictive values?

Answer 32

Predictive values

Sensitivity and Specificity are properties of a test and not affected by prevalence

Question 33

Sensitivity is?

Answer 33

Positive test in disease

True positive test over everyone with disease

Question 34

Specificity is?

Answer 34

Negative test in health

True negative test over everyone with a negative test

Question 35

Answers question - if a test is positive then what percent of people will have the disease?

Answer 35

Positive predictive value

Question 36

Answers question - if a test is negative then what percent of people will not have the disease?

Answer 36

Negative predictive value

Question 37

Positive predictive value is?

Answer 37

True positive test over all positive tests

Question 38

Negative predictive value is?

Answer 38

True negative test over all negative tests (true and false)