Ch. 12 Biostats & Eco

Question 1

ECHO stands for

Answer 1

Economic outcomes
Clinical outcomes
Humanistic Outcomes

Question 2

Cost Minimization Analysis (CMA)

Answer 2

Used when two or more interventions have already demonstrated equivalency in outcomes and the costs of each intervention are being compared

Question 3

Cost Benefit Analysis

Answer 3

Systematic process for calculating and comparing benefits and costs of an intervention in terms of monetary units

Question 4

Cost Effectiveness Analysis (CEA)

Answer 4

Compares clinical effects to net costs. Can only compare one type of outcomes. Uses natural units for the outcome (BP, life-years gained)

Question 5

Cost Utility Analysis (CUA)

Answer 5

Includes quality of life in terms of years gained in quality-adjusted life years (QALYs). Does not measure the “quality” or “utility” of those years

Question 6

Standard deviation

Answer 6

Indicates how spread out the data is, and to what degree the data is dispersed away from the MEAN

Question 7

Negative skew

Answer 7

Has more high values

Question 8

Positive skew

Answer 8

Has more low values

Question 9

In skewed data, it is best to use this central tendency value

Answer 9

The median

Question 10

Type I Error

Answer 10

False positive (most common error), CI= 1 - alpha
Rejects the null hypothesis in error

Question 11

Type II Error

Answer 11

False negative (beta)
Accepts the null hypothesis in error

Question 12

Study Power

Answer 12

Probability that a test will reject the null hypothesis correctly (the power to avoid Type II error correctly)
Power= 1 - beta

Question 13

Relative Risk (RR)

Answer 13

Risk in tx group/Risk in control group

Interprets how likely the tx group risk will occur compared to the control group

Question 14

Relative Risk Reduction (RRR)

Answer 14

1-RR

Interprets how much less likely the tx group risk will occur compared to the control group

Question 15

Absolute Risk Reduction (ARR)

Answer 15

Risk in control group - Risk in tx group

Question 16

Number Needed to Treat (NNT)

Answer 16

1/(Risk in control group-Risk in tx group) OR 1/ARR

Round UP to avoid overestimating

Question 17

Number Needed to Harm (NNH)

Answer 17

1/ARR

Round DOWN to avoid underestimating

Question 18

Odds Ratio

Answer 18

The probability that an event will occur, versus the probability that it will not occur (used in case-control studies)
OR= AD / BC

Question 19

Hazard Ratio

Answer 19

Survival analysis

HR= Hazard rate in the tx group / Hazard rate in the control group

Question 20

Types of discrete data

Answer 20

Nominal (name) i.e. male, female

Ordinal (order) i.e. pain scale, NYHA class

Question 21

Types of continuous data

Answer 21

Ratio, has a meaningful 0 value (i.e. blood pressure)

Interval, does not have a meaningful 0 (i.e. degrees)

Question 22

Use of Chi Square Test

Answer 22

In discrete data; tests for difference between/among tx groups

Question 23

Use of ANOVA/F-test

Answer 23

In continuous data with 3 or more sample groups

Question 24

Use of Student T-test

Answer 24

In continuous data with one sample group

Question 25

Correlation

Answer 25

Determines if one variable is related to another (can be positive with increase to right, or negative with decrease to the right)

Question 26

Types of correlation

Answer 26

Spearman’s Rank Order: (Rho) tests correlation in ordinal, ranked data
Pearson’s Correlation Coefficient: (r) used in continuous data (indicates the strength and direction of the relation between variable)

Question 27

Linear Regression use

Answer 27

Continuous data

Question 28

Logistic Regression use

Answer 28

Categorical data

Question 29

Cox Regression

Answer 29

Categorical data in survival analysis

Question 30

Sensitivity

Answer 30

True Positive

A / (A+C) x 100

Question 31

Specificity

Answer 31

True Negative

D / (B+D) x 100

Question 32

Medical studies from most to least reliable

Answer 32

Systematic reviews and Meta-analysis > RCTS > Cohort > Case-control > Case Series and Reports > Expert opinion