Equations

Question 1

How do you calculate positive predictive value?

Answer 1

TP / (FP + TP)

Question 2

How do you calculate negative predictive value?

Answer 2

TN / (FN + TN)

Question 3

How do you calculate sensitivity?

Answer 3

TP / (TP + FN)

Question 4

How do you calculate specificity?

Answer 4

TN / (TN + FP)

Question 5

How do you calculate NNT?

Answer 5

1/ absolute risk reduction
ARR= risk in control - risk in treatment

Question 6

How do you calculate prevalence Al pretext probability?

Answer 6

(TP + FN) / total

Question 7

How do you calculate vaccine efficacy?

Answer 7

1- risk ratio
Risk ratio= risk of disease in vaccinated / risk of disease in unvaccinated

Question 8

How do you calculate absolute risk reduction and relative risk reduction?

Answer 8

ARR the absolute difference in event rates= absolute risk in control - absolute risk in treatment
RR= absolute risk in treatment/ absolute risk in control
RRR the proportional reduction in event rates = ARR/ (1-RR)
NNT= 1/ ARR

Question 9

What is a likelihood ratio?

Answer 9

Helps put something into context with your pretest probability

LR+= TP/FP
LR-= FN/TN

Question 10

How do you calculate attributable risk?

Answer 10

AR= Incidence in exposed - Incidence in unexposed

Question 11

What is the equation for oxygen delivery?

Answer 11

CaO2 x CI x 10
CaO2= (1.36 x Hb x Sat) + (0.003 x paO2)

Question 12

Rattle off some buzzword associations with occupational/environmental

Answer 12

Question 13

Rattle off some buzzword associations with occupational/environmental

Answer 13