Intro to Laboratory Medicine

Question 1

At what serum HCG level is pregnancy positive?

Answer 1

> 5mIU/ml

Question 2

What is CEA?

Answer 2

Carcinoembryonic antigen which is a proposed tumor marker for colon cancer

Question 3

What is sensitivity?

Answer 3

The least number of false negatives

TP/(TP+FN)

Question 4

What is specificity?

Answer 4

Highest number of true positives

TN/(TN+FP)

Question 5

What is prevalence?

Answer 5

% of people with disease in a given pop at a point in time

(TP+FP)/total

Question 6

What is the predictive value?

Answer 6

TP/(TP+FP)

Question 7

Does prevalence have an effect on sensitivity and specificity of the test?

Answer 7

Nope

Question 8

What is the best cut-off value?

Answer 8

One with the highest sensitivity and highest specificity

Question 9

Is a screening test highly sensitive or highly specific?

Answer 9

Highly sensitive (no FN’s) but not very specific (some FP’s)

Question 10

Is a diagnostic test highly sensitive or highly specific?

Answer 10

Highly specific (no FP’s)

Question 11

What are DRG’s?

Answer 11

Diagnostic related groups which classify hospital patients into one of approximately 500 diagnostic groups

Question 12

What are the types of sickle cell crisis?

Answer 12

Infarction
Hemolytic
Aplastic

Question 13

Whats the difference between hemolytic and aplastic?

Answer 13

They are both RBC destruction in hemolysis the marrow responds appropriately but in aplastic the bone marrow shuts down

Question 14

Is a discharge diagnosis specific or general?

Answer 14

Specific

Question 15

Is the DRG payment to a hospital affected by an inappropriate diagnosis?

Answer 15

Yes, the payment goes down. The hospital actually ends up losing money.