BioStats

Question 1

Relative Risk Reduction (RRR)

Answer 1

(Risk in unexposed)-(Risk in exposed)/Risk in unexposed
ARR/Rate in the control

Question 2

Number Needed to Harm (NNH)

Answer 2

1/Absolute Risk Increase (ARI)

Question 3

Absolute Risk Increase (ARI)

Answer 3

ARI=Rate in treatment- Rate in the placebo

Question 4

Normal Distribution

Answer 4

1 STD - 68%
2 STD - 95%
3 STD - 99.7%

Question 5

Positive Likelihood Ratio

Answer 5

LR + = Sensitivity/(1-Specificity)

Question 6

Negative Likelihood Ratio

Answer 6

LR - = (1-Sensitivity)/Specificity

Question 7

Likelihood Ratio Interpretation

Answer 7

The higher the number, like 10, the more evidence to rule in disease
the lower the number, like <0.1, the more evidence to rule out disease

Question 8

Absolute Risk Reduction (ARR)

Answer 8

ARR = Rate in control - Rate in the treatment

Question 9

Relative Risk (RR)

Answer 9

Rate in the treatment/Rate in the control

Question 10

Number Needed to Treat (NNT)

Answer 10

1/ARR

Question 11

Attributable Risk Percentage (ARP)

Answer 11

ARP=Risk in exposed - Risk in control/Risk in exposed
(RR-1)/RR

Question 12

Hazard Ratio

Answer 12

Rate disease/Rate in the control

Question 13

False Positive Rate

Answer 13

1-specificity

Question 14

False Negative Rate

Answer 14

1-Sensitivity

Question 15

Odds Ratio

Answer 15

(A/C)/(B/D)
AD/BC

Question 16

Positive Predictive Value

Answer 16

TP/(TP+FP)

Question 17

Negative Predictive Value

Answer 17

TN/(TN+FN)

Question 18

Negatively skewed Distribution

Answer 18

Mode>Median>Mean

Question 19

Positively Skewed Distribution

Answer 19

Mean>Median>Mode