Intro to Laboratory Tests

Question 1

Purpose of laboratory tests

Answer 1

1. Screen for disease2. Confirm disease3. Monitor disease status

Question 2

Parsimonious

Answer 2

the quality of being careful with money and sparing the use of resources, excessively frugal

Question 3

Sensitivity

Answer 3

Likelihood of having positive result in people who have a selected diseaseTP / (TP + FN)100% sensitivity means no FN

Question 4

A test with high sensitivity is best for what?

Answer 4

screening

Question 5

Specificity

Answer 5

Likelihood of having negative results in non diseased peopleTN / (TN + FP)100% specificity means no FP

Question 6

A test with high specificity is best for what?

Answer 6

confirming disease

Question 7

Negative predicative value

Answer 7

Likelihood that a negative test result excludes diseaseTN / (TN + FN)

Question 8

Positive predictive value

Answer 8

Likelihood that a positive test result confirms diseaseTP / (TP + FP)

Question 9

Prevalence

Answer 9

Total number of people with disease in the population under study

Question 10

High precision means

Answer 10

the same test results are obtained with repetitive measures

Question 11

Likelihood of an outlier increases as …

Answer 11

the number of tests ordered increases

Question 12

Variables affecting laboratory results in newborns

Answer 12

1. increased Hb concentration HbF2. lack of IgM3. IgG antibodies are of maternal origin

Question 13

Variables affecting laboratory results in children

Answer 13

1. Higher serum alkaline phosphate than adults2. Higher serum phosphate3. Lower Hb

Question 14

Variables affecting laboratory results in adults

Answer 14

1. serum iron, ferritin & Hb lower in women than men2. elderly-decreased GFR and CrCl-increased ALP-males have normal decrease in Hb w/ decreased testosterone