Login

Contact Us
Homework
Homework Questions? Ask a Tutor for Answers ASAP
Not a Homework Question?
How JustAnswer Works:
Ask an Expert
Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
Get a Professional Answer
Via email, text message, or notification as you wait on our site.
Ask follow up questions if you need to.
100% Satisfaction Guarantee
Rate the answer you receive.
Ask Chris M. Your Own Question
Chris M.
,
M.S.W. Social Work
Category:
Homework
Satisfied Customers:
2782
Experience:
Master's Degree, strong math and writing skills, experience in oneonone tutoring (college English)
22285537
Type Your Homework Question Here...
Chris M. is online now
can you please answer these questions for me thanks Sensitivity/Specificity
Resolved Question:
can you please answer these questions for me?
thanks
Sensitivity/Specificity Problem Set.
Clearly mark your responses for each question.
1) Sensitivity is:
A. The probability that a test correctly classifies as positive those who have preclinical disease.
B. The probability that a test correctly classifies individuals without preclinical disease as negative
C. The probability that those who test positive have the preclinical disease
D. The probability that those who test negative do not have the preclinical disease
2) Specificity is:
A. The probability that a test correctly classifies as positive those who have preclinical disease.
B. The probability that a test correctly classifies individuals without preclinical disease as negative
C. The probability that those who test positive have the preclinical disease
D. The probability that those who test negative do not have the preclinical disease
A screening examination was performed on 250 persons for Factor X, which is found in disease Y. A definitive diagnosis for disease Y among the 250 persons had been obtained previously. The results are charted below:
RESULTS OF DIAGNOSIS
TEST RESULTS Disease Y Present Disease Y Absent
Positive for Factor X 40 60
Negative for Factor X 10 140
3) The sensitivity of this test is expressed as:
A. 40%
B. 70%
C. 29%
D. 80%
4) The specificity of this test is expressed as:
A. 40%
B. 70%
C. 7%
D. 80%
5) The positive predictive value of this test is:
A. 40%
B. 70%
C. 7%
D. 80%
6) The negative predictive value of this test is:
A. 40%
B. 70%
C. 93%
D. 80%
7) If the same screening test is conducted in two populations, one with a high prevalence of the disease and one with a low prevalence of the disease, assuming the sensitivity and specificity of the screening test are the same, which of the following statements about positive predictive value (PPV) applies:
A. PPV is higher in the screened population with higher prevalence
B. PPV is lower in the screened population with higher prevalence
C. PPV is the same in both populations
D. It cannot be determined
8) Lead time bias can be described as:
A. An apparently lower survival rate among persons screened compared to an unscreened group.
B. A bias that occurs because screening tends to identify cases with less aggressive forms of the disease
C. A similar survival time for persons identified during a screening program relative to persons who are diagnosed by clinical symptoms.
D. An apparently longer survival time among those identified during a screening program because they were identified at an earlier stage of their disease
9) LengthBias can be described as:
A. An apparently lower survival rate among persons screened compared to an unscreened group.
B. A bias that occurs because screening tends to identify cases with less aggressive forms of the disease
C. A similar survival time for persons identified during a screening program relative to persons who are diagnosed by clinical symptoms.
D. An apparently longer survival time among those identified during a screening program because they were identified at an earlier stage of their disease
A new screening test for a disease is developed for use in the general population. The sensitivity and specificity of the new test are 60% and 70%, respectively. Four hundred (400) people are screened at a clinic during the first year the new test is implemented. (Assume the true prevalence of the disease among clinic attendees is 10%.)
Calculate the following values:
10) The predictive value of a positive test is:
A. 13.3%
B. 18.2%
C. 24%
D. 22.2%
11) The number of false positives is:
A. 108
B. 132
C. 24
D. 252
Submitted:
5 years ago.
Category:
Homework
Share this conversation
Expert:
Chris M.
replied 5 years ago.
THIS ANSWER IS LOCKED!
You need to spend $3 to view this post.
Add Funds
to your account and buy credits.
Chris M. and other Homework Specialists are ready to help you
Ask your own question now
Share this conversation
Related Homework Questions
Question
Date Submitted
I have a column that divides j/s. This sometimes results in
1/16/2017
1/16/2017
HomeworkPete
Translate the sentence below into English. Pienso que nunca
1/8/2017
1/8/2017
Lane
I need help with my preexam for Penn high school this is
12/30/2016
1/4/2017
Wiz of All
NOT GLENN NOR F. NAZ PLEASE In the story titled "Macbeth" by
12/29/2016
12/29/2016
Manal Elkhoshkhany
Exam Number: 986159RR
12/26/2016
1/15/2017
GLENN
Need help with a couple assignment questions
12/24/2016
12/24/2016
StructuralEng
FOR LogicPro Only, I have another database question. Its a
12/19/2016
12/20/2016
LogicPro
Convert any of your earlier programs that use message boxes
12/15/2016
1/13/2017
LogicPro
Read the Funeral Oration of Pericles in the Ancient History
12/14/2016
12/16/2016
Donna Kakonge
Ineed help with chemstry exams, i have a few exams that i
12/14/2016
12/14/2016
GLENN
X
Ask a Tutor
Get a Professional Answer. 100% Satisfaction Guaranteed.
20 Tutors are Online Now
Type Your Homework Question Here...
characters left: