statistics

Question 1

levels of evidence

Answer 1

1. randomized controlled trial
2. prospective cohort
3. case control, retrospective
4. case series
5. expert opinion

Question 2

error types

Answer 2

1. false positive (alpha)

2. false negative (beta) (increase power to prevent)

Question 3

standard deviation

Answer 3

if continuous data with normal (Gausian) distribution then
1 SD = 68%
2 SD = 95%
3 SD = 99.7%

Question 4

test to use

Answer 4

compare two dichotomous groups (yes/no; male/female, etc) then use chi square

• compare two continuous groups then correlation coefficient
• compare dichotomous to continuous then t-test
• compare >3 continuous then ANOVA
• ordinal data (ex satisfaction) then chi square

Question 5

regression model

Answer 5

allows for multiple independent factors to predict outcome variable

• outcome variable continuous then linear regression
• outcome variable categorical then logistic regression