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Here is a question on USMLE World that I think may be an error.
A new test to diagnose a UTI in women is being evaluated. The gold standard is a positive urine dipstick plus urine culture. Results are given below:
+ Dipstick + UC - Dipstick + UC
Test 60 20
+
- 440 180
What is the new test's specificity?
A. 10
B. 30
C. 56
D. 70
E. 90
I got 90% from my calculations of specificity. However, UW says that the specificity would be 90% and then goes on to give the predictive value of 10%. Is this an error or am I missing something?
A new test to diagnose a UTI in women is being evaluated. The gold standard is a positive urine dipstick plus urine culture. Results are given below:
+ Dipstick + UC - Dipstick + UC
Test 60 20
+
- 440 180
What is the new test's specificity?
A. 10
B. 30
C. 56
D. 70
E. 90
I got 90% from my calculations of specificity. However, UW says that the specificity would be 90% and then goes on to give the predictive value of 10%. Is this an error or am I missing something?