Formulas

Question 1

Acceptable Blood Loss

Answer 1

(Hct original - Hct final)/Hct average * EBV
EBV = men and children 1-2 is 75ml/kg, women 65ml/kg, neonates 85 ml/kg, preemies 90ml/kg

Question 2

incidence

Answer 2

new case/pop at risk

Question 3

prevalence

Answer 3

cases at a given time/population at risk

Question 4

relative risk

Answer 4

a/(a+b) / c/(c+d)

Question 5

odds ratio

Answer 5

ad/bc

Question 6

sensitivity

Answer 6

a/a+c, ability of a test to give positive result when patient is positive

Question 7

specificity

Answer 7

d/b+d, ability of test to give negative finding when patient does not have disease

Question 8

type I error

Answer 8

false positive

Question 9

type II error

Answer 9

false negative

Question 10

sampling error contributors

Answer 10

bias and random variation

Question 11

chi-squared test

Answer 11

categorical variables, compares distribution of test results with normal distribution to evaluate independence

Question 12

t-test

Answer 12

continuous variables, comparing means of TWO populations

Question 13

ANOVA

Answer 13

continuous variables, means of multiple groups