Selection Bias

Question 1

SELF-SELECTION/ NON-RESPONSE BIAS

Answer 1

May exist in any study design that relies on individuals to agree to participate in the study

Question 2

CONTROL
SELECTION BIAS

Answer 2

Occurs in case-control studies when the control group selected is not representative of the population that produced the cases

Question 3

LOSS TO
FOLLOW-UP BIAS

Answer 3

Occurs in longitudinal studies when differential loss to follow-up exists

Question 4

BERKSON’S BIAS

Answer 4

Occurs because the exposure values in hospitalized subjects, particularly controls, may not be the same as exposure values for the source population

Question 5

HEALTHY
WORKER EFFECT

Answer 5

1. The person may be selected for employment based on good health
2. The person who continued to work may be selected to continue based on good health

Question 6

SURVIVOR EFFECT

Answer 6

A group in a target population has enhanced survival and thus, their participation is related to the exposure, outcome, and/or confounding variable