AND ANSWERS | 100% PASS
Which of the following types of bias is most commonly associated with a
case-control study? - 🧠 ANSWER ✔✔Recall bias
A new non-invasive screening test is proposed that is claimed to be able to
identify patients with impaired glucose tolerance based on a battery of
questions related to health behaviors. The new test is given to 75 patients.
Based on each patient's responses to the questions they are classified as
positive or negative for impaired glucose tolerance. Each patient also
submits a blood sample and their glucose tolerance status is determined.
The results are tabulated below
What is the sensitivity of the screening test?
, What is the false positive fraction of the screening test? - 🧠 ANSWER
✔✔Sensitivity = #(true positives)/(#(true positives)+#(false negatives)) =
17/(17+8) = 17/25 = 0.68
Answer: 0.68
False positive fraction = #(false positives)/(#(false positives)+#(true
negatives)) =13/(13+37)
= 13/50 = 0.26
Answer: 0.26
A study is designed to evaluate the impact of a daily multivitamin on
students' academic performance. One hundred sixty students are randomly
assigned to receive either the multivitamin or a placebo and are instructed
to take the assigned drug daily for 20 days. On day 20, each student takes
a standardized exam and the mean exam scores are compared between
groups. This study is an example of a - 🧠 ANSWER ✔✔Randomized
Control Trial
When estimating sample size, it is not important for researchers to account
for attrition or loss of participants during follow-up. - 🧠 ANSWER ✔✔True