Biostats

Question 1

compares group with a given exposure to those without exposure

Answer 1

Cohort– relative risk

Who will develop disease

Question 2

compares a group of people with a DISEASE to those without a disease

Answer 2

Case control– odds ratio

Ask what happened

Question 3

Phase 1-4

Answer 3

1- is it safe
2- does it work; side effects; efficacy
3- same or better
4-long term side effects?

Question 4

Study only looking at inpatients

Answer 4

Berksons bias

Question 5

type I error

Answer 5

see a difference when no difference exists– i.e. reject null when we should accept

Question 6

type II error

Answer 6

don’t see a difference when there is one– reject alternative when we should accpet alternative

Question 7

Beta is?

Answer 7

The probability of making a type II error

Question 8

statistical power=

Answer 8

1-beta

statistical power is the probability of rejecting the the null hypothesis when it is indeed false

Question 9

Null hypothesis is not rejected when …95%

Answer 9

when 95% confidence interval is zero when comparing means

or crosses 1 when comparing odds ratio or relative risk

Question 10

test checks difference between 2 means

Answer 10

T test

Question 11

test checks difference between 3 or more means

Answer 11

ANOVA

Question 12

test checks difference between 2 or more CATEGORICAL outcomes

Answer 12

Chi square

Question 13

Preventions?

Answer 13

Primary prevent
Secondary screen
Tertiary treat