Bias - measurement

Question 1

Recall bias

Answer 1

Subjects often recall risk factors differently depending on their disease status

Case-control studies particularly vulnerable

Question 2

Reporting bias

Answer 2

When a larger percentage of either the cases or controls report an exposure due to attitudes, perceptions or other concerns

Question 3

Observer bias

Answer 3

When a researcher knowingly or unknowingly evaluates a variable depending on the status of the individual under study

Question 4

Surveillance bias

Answer 4

Disease may be better ascertained in a monitored population than the general population

Question 5

Work up bias (verification bias)

Answer 5

During assessment of validity of a diagnostic test, the execution of the gold standard test may be influenced by the results of the assessed new instrument

Question 6

Misclassification bias

Answer 6

In extreme cases measurement bias may lead to misclassification - only amounts to bias if one sided

Question 7

Desirability bias

Answer 7

Patients may choose socially desirable answers to provide during data collection, distorting the true picture

Question 8

Hawthorne effect

Answer 8

Observed respondents minimizing perceived deviation from the norm