Final exam

Question 1

2 sources of immigrative selection bias (RCT/cohort)

Answer 1

1. Poor allocation concealment

2. Sample selection (volunteer bias, eligibility - healthy worker bias & survival bias)

Question 2

2 sources of emigrative selection bias

Answer 2

1. Loss to follow up

2. Missing data

Question 3

2 sources of selection bias in case-control studies

Answer 3

1. Control selection (Berkson’s bias)

2. Matching

Question 4

3 types of information bias related to exposure

Answer 4

1. Poor recall
2. Recall bias
3. Interviewer bias

Question 5

3 types of information bias related to outcome

Answer 5

1. Observer bias
2. Surveillance/detection bias
3. Reporting bias

Question 6

Formula for correcting a table

Answer 6

original count = sensX + (1-spec)(TotE+ - X)

Question 7

Population attributable fraction when given P(E)

Answer 7

P(E)(RR-1)/[P(E)(RR-1)+1]