Prep for USMLEPrep for USMLE
         Forum      |     Resources New Posts   |   Register   |   Login

 3 part sequential question  

Post Reply  
  • 0/5
  • 1
  • 2
  • 3
  • 4
  • 5

Author1 post

An imaginary study involving 650 people was conducted to assess the performance of the stool antigen assay in detecting a helicobacter pylori infection. After collecting all the test results, it was found that 250 people tested positive and 400 people tested negative. If the positive and negative predictive value were 80% and 75%, respectively, then what proportion of people with the infection were identified by the test?

(A) 300/650
(B) 200/250
(C) 200/300
(D) 200/650

How would the sensitivity of the test change if the number of positive tests was higher?

(A) It would increase
(B) It depends on the prevalence
(C) Not enough information is provided
(D) It would decrease

What would the sensitivity of the test be if 10 people with the condition did not test negative?

(A) 200/310
(B) 210/300
(C) 210/310
(D) 200/300

The answers and explanations can be found on youtube via this link...

Bookmark and Share

This thread is closed, so you cannot post a reply.

Login or Register to post messages

show Similar forum topics

Sequential Questions & Lab Values
Sequential loss of hormones
Goljan part 1 or both part 1 and 2 for step 1
show Related resources

Conrad Fischer's Internal Medicine Question Book

Advertise | Support | Premium | Contact