Question 13
Four prior case-control studies and three cohort studies of caffeine intake during pregnancy have shown an increased risk of low-birth-weight infants among women who consumed high amounts of caffeine.
Answer
Consistency
Dose-response
Temporality
Biological plausibility
Strength of the association
Question 14
The risk of low birth weight increased as the caffeine consumption increased. Compared to women who did not consume any caffeine during pregnancy, the relative risk of giving birth to a low-birth-weight infant was 1.4 for women who had low caffeine consumption, 2.3 for women who had moderate caffeine consumption, and 5.6 for women who had high caffeine consumption.
Answer
Consistency
Dose-response
Temporality
Biological plausibility
Strength of the association
Question 15
Use the following information to answer questions 15-17.
Suppose that your company has just developed a new screening test for a disease and you are in charge of testing its validity and feasibility. You decide to evaluate the test on 1000 individuals and compare the results of the new test to the gold standard. Below are the results.
Gold Standard Determination of Disease
Total
Results of Screening Test
Yes
No
Positive
285
7
292
Negative
15
693
708
Total
300
700
1,000
Calculate the sensitivity of the new screening test. Answer
285/300 = 95%
285/1000 = 28.5%
15/300 = 5%
693/700 = 99%
Question 16
What is the correct interpretation of the results of a calculation of specificity?
Answer
The test is able to correctly classify as positive 95% of those with the disease.
The test is able to correctly classify as negative 99% of those without the disease.
Of those who screened positive, 97.6% of them actually have the disease.
Of those who screened negative, 97.9% of them actually do not have the disease.
