GORDIS EPIDEMIOLOGY EXAMINATION
TEST COMPLETE QUESTIONS AND
SOLUTIONS
●● Selection Bias
Answer: Error due to systematic differences in exposures between those
who are selected and those who are not (deals with exposed/unexposed
AND cases/non-cases)
●● Prevention and control of bias can be accomplished at 3 levels
Answer: 1. Ensuring that the study design is appropriate for addressing
the study hypotheses
2. Establishing and carefully monitoring procedures of data collection
that are valid and reliable
3.Using appropriate analytic procedures
●● Unbiased
Answer: Free from all prejudice and favoritism; fair
●● Exclusion bias
,Answer: When investigators apply different eligibility criteria to the
cases and to the controls in regard to which clinical conditions in the
past would permit eligibility in the study and which would serve as the
basis for exclusion.
●● Misclassification of exposure is non-differential
Answer: if the misclassification is unrelated to the occurrence or
presence of disease.
●● Misclassification of exposure is differential
Answer: if the misclassification is different for those with and without
disease.
●● Misclassification of disease is non-differential
Answer: if the misclassification is unrelated to exposure.
●● Misclassification of disease is differential
Answer: if the misclassification is different for those with and without
exposure.
●● Misclassification of exposure
Answer: Some people who are smokers (true exposure) may be
misclassified as non-smokers, while some others who are non-smokers
may be misclassified as smokers
, ●● Misclassification of outcome
Answer: Some people who have the disease (true cases) may be
misclassified as non-cases, and some without disease (true non-cases)
may be classified as cases.
●● Information bias
Answer: Results from a systematic tendency for individuals selected for
inclusion in the study to be erroneously placed in different
exposure/outcome categories, thus leading to misclassification.
●● Information bias is equally likely in both
Answer: prospective and retrospective studies.
●● What is inference?
Answer: The act of passing from statistical sample data to
generalizations (as of the value of population
parameters) usually with calculated degrees of
certainty
The process of passing from observations and
axioms to generalizations
●● Inductive reasoning
TEST COMPLETE QUESTIONS AND
SOLUTIONS
●● Selection Bias
Answer: Error due to systematic differences in exposures between those
who are selected and those who are not (deals with exposed/unexposed
AND cases/non-cases)
●● Prevention and control of bias can be accomplished at 3 levels
Answer: 1. Ensuring that the study design is appropriate for addressing
the study hypotheses
2. Establishing and carefully monitoring procedures of data collection
that are valid and reliable
3.Using appropriate analytic procedures
●● Unbiased
Answer: Free from all prejudice and favoritism; fair
●● Exclusion bias
,Answer: When investigators apply different eligibility criteria to the
cases and to the controls in regard to which clinical conditions in the
past would permit eligibility in the study and which would serve as the
basis for exclusion.
●● Misclassification of exposure is non-differential
Answer: if the misclassification is unrelated to the occurrence or
presence of disease.
●● Misclassification of exposure is differential
Answer: if the misclassification is different for those with and without
disease.
●● Misclassification of disease is non-differential
Answer: if the misclassification is unrelated to exposure.
●● Misclassification of disease is differential
Answer: if the misclassification is different for those with and without
exposure.
●● Misclassification of exposure
Answer: Some people who are smokers (true exposure) may be
misclassified as non-smokers, while some others who are non-smokers
may be misclassified as smokers
, ●● Misclassification of outcome
Answer: Some people who have the disease (true cases) may be
misclassified as non-cases, and some without disease (true non-cases)
may be classified as cases.
●● Information bias
Answer: Results from a systematic tendency for individuals selected for
inclusion in the study to be erroneously placed in different
exposure/outcome categories, thus leading to misclassification.
●● Information bias is equally likely in both
Answer: prospective and retrospective studies.
●● What is inference?
Answer: The act of passing from statistical sample data to
generalizations (as of the value of population
parameters) usually with calculated degrees of
certainty
The process of passing from observations and
axioms to generalizations
●● Inductive reasoning
