Practice for HLSC 4P99 Exam UPDATED ACTUAL
QUESTIONS AND CORRECT ANSWERS
A hypothetical study is conducted to determine rates of iron deficiency anemia among 400
adult male miners, some of whom use dental floss and some of whom do not. The following
data gathered and reflected in this table. What type of study is this - CORRECT
ANSWER Cohort
The hypothesized use of penicillin as a treatment by Alexander Fleming was discovered
through __________ because he went on holiday and left a sandwich on table - CORRECT
ANSWER Molecular observation
You have just completed a history and physical exam of a patient for whom you consider the
diagnosis of systemic lupus possible, but not likely. You order a battery of six different tests
for the disease. The results to of 4 are positive and the results of the other 2 are negative. To
determine the probability of SLE at this point, you would need to know - CORRECT
ANSWER Prior probability, sensitivity, specificity
Identify the correct notation for determining the probability of a missing patient with prostate
cancer and report a negative digital rectal exam - CORRECT ANSWER P (T- | D+)
An absolute risk reduction of 0.2 would require treatment for __________ patients to observe
effiacy in one patient - CORRECT ANSWER 5
Identidying the positiveity criterion in an ROC curve is dependent on the direct of the test and
_________ - CORRECT ANSWER The prognostics of the condition
A new test for the noninvasive detection of alcohol use is being developed. It is applied to a
population of 200 workers who insist they do not drink during work hours. Based on a gold
standard - a breath test to indicate blood alcohol level - 20 of the 200 workers have detectable
alcohol levels during the workday. The new test detects 12 cases of alcohol use, of which 8
are positive by the gold standard and 4 are negative. Based on these data, the sensitivity of
the new test is - CORRECT ANSWER 40%
, In untreated patients, disease X causes death in 22% and serious complications in 1%. In
treated patients, the mortality rate decreases to 6%, but the rate of serious complications
increases to 5%. What is the number needed to treat in this scenario? - CORRECT
ANSWER 6.25
What knowledge is required to determine if expectation bias was avoided?
A. Matching
B. Blinding
C. Randomization
D. All of the above - CORRECT ANSWER Blinding
What is not a form of bias?
A. Confounding bias
B. Non-response bias
C. Generarlizability bias
D. Measurement bias - CORRECT ANSWER C. Generarlizability bias
Paying attention to and minimzing known challenges in epidemiological research (e.g., bias
and confounding) is critical for:
A. Detecting potential sources of systematic error
B. Classifying exposures and outcomes
C. Study validity
D. Study design and analysis - CORRECT ANSWER C. Study validity
When is the risk of selection bias most prominent?
A. When simple randomization is conducted
B. When stratification is used
C. When randomization is restricted to ensure equal number of patients in each group
D. When there is an unequal of patients assigned to either the treatment group or the control
group - CORRECT ANSWER D. When there is an unequal number of patients
assigned to either groups
QUESTIONS AND CORRECT ANSWERS
A hypothetical study is conducted to determine rates of iron deficiency anemia among 400
adult male miners, some of whom use dental floss and some of whom do not. The following
data gathered and reflected in this table. What type of study is this - CORRECT
ANSWER Cohort
The hypothesized use of penicillin as a treatment by Alexander Fleming was discovered
through __________ because he went on holiday and left a sandwich on table - CORRECT
ANSWER Molecular observation
You have just completed a history and physical exam of a patient for whom you consider the
diagnosis of systemic lupus possible, but not likely. You order a battery of six different tests
for the disease. The results to of 4 are positive and the results of the other 2 are negative. To
determine the probability of SLE at this point, you would need to know - CORRECT
ANSWER Prior probability, sensitivity, specificity
Identify the correct notation for determining the probability of a missing patient with prostate
cancer and report a negative digital rectal exam - CORRECT ANSWER P (T- | D+)
An absolute risk reduction of 0.2 would require treatment for __________ patients to observe
effiacy in one patient - CORRECT ANSWER 5
Identidying the positiveity criterion in an ROC curve is dependent on the direct of the test and
_________ - CORRECT ANSWER The prognostics of the condition
A new test for the noninvasive detection of alcohol use is being developed. It is applied to a
population of 200 workers who insist they do not drink during work hours. Based on a gold
standard - a breath test to indicate blood alcohol level - 20 of the 200 workers have detectable
alcohol levels during the workday. The new test detects 12 cases of alcohol use, of which 8
are positive by the gold standard and 4 are negative. Based on these data, the sensitivity of
the new test is - CORRECT ANSWER 40%
, In untreated patients, disease X causes death in 22% and serious complications in 1%. In
treated patients, the mortality rate decreases to 6%, but the rate of serious complications
increases to 5%. What is the number needed to treat in this scenario? - CORRECT
ANSWER 6.25
What knowledge is required to determine if expectation bias was avoided?
A. Matching
B. Blinding
C. Randomization
D. All of the above - CORRECT ANSWER Blinding
What is not a form of bias?
A. Confounding bias
B. Non-response bias
C. Generarlizability bias
D. Measurement bias - CORRECT ANSWER C. Generarlizability bias
Paying attention to and minimzing known challenges in epidemiological research (e.g., bias
and confounding) is critical for:
A. Detecting potential sources of systematic error
B. Classifying exposures and outcomes
C. Study validity
D. Study design and analysis - CORRECT ANSWER C. Study validity
When is the risk of selection bias most prominent?
A. When simple randomization is conducted
B. When stratification is used
C. When randomization is restricted to ensure equal number of patients in each group
D. When there is an unequal of patients assigned to either the treatment group or the control
group - CORRECT ANSWER D. When there is an unequal number of patients
assigned to either groups
