Common Errors in Statistical Studies

Question 1

selection biases

Answer 1

ascertainment (sampling) bias
nonresponse bias
Berkson bias
prevalence (neyman) bias
attrition bias

Question 2

observational bias

Answer 2

recall bias
observer bias
reporting bias
surveillance (detection) bias

Question 3

ascertainment (sampling) bias

Answer 3

study population differs from target population due to nonrandom selection methods

Question 4

nonresponse bias

Answer 4

high nonresponse rate to surveys/questionnnaires can cause errors if non responders differ in some way from responders

Question 5

Berkson bias

Answer 5

disease studied using only hospital-based patients may lead to results not applicable to target population

Question 6

prevalence (Neyman) bias

Answer 6

exposures that happen long before disease assessment can cause study to miss diseased patients that die early or recover

Question 7

attrition bias

Answer 7

significant loss of study participants may cause bias if those lost to follow-up differ significantly from remaining subjects

Question 8

recall bias

Answer 8

common in retrospective studies

subjects with negative outcomes are more likely to report certain exposures than control subjects

Question 9

observer bias

Answer 9

observers misclassify data due to individual differences in interpretation or preconceived expectations regarding the study

Question 10

reporting bias

Answer 10

subjects over- or under-report history due to perceived social stigmatization

Question 11

surveillance (detection) bias

Answer 11

risk factor itself causes increased monitoring in exposed group relative to unexposed group, which increases probability of identifying a disease