Chapter 6

Question 1

What is CV?

Answer 1

Coefficient of variation. Compares a day of work to another similar day. SD/Mean x 100

Question 2

1+ SD

Answer 2

68%

Question 3

2+ SD

Answer 3

95%

Question 4

3+ SD

Answer 4

99%

Question 5

Preanalytical error

Answer 5

Incorrect test requested, wrong patient, wrong time, wrong container, incorrect labeling, incorrect order of draw, improper specimen processing

Question 6

Postanalytic errors

Answer 6

Reporting and recording inaccurately

Question 7

Analytic sensitivity

Answer 7

How much of a given substance is measured; smaller amounts = more sensitive

Question 8

Analytic specificity

Answer 8

What is being measured; the assay only measures the analyte being tested and nothing else

Question 9

Clinical sensitivity

Answer 9

The proportion of subjects with the disease or condition that test positive

Question 10

Clinical specificity

Answer 10

The proportion of subjects without the disease or condition who test negative

Question 11

False positive errors

Answer 11

Over centrifugation, dirty glassware, hemolysis, inadequate dispersal of serum, extended incubation,

Question 12

False negative errors

Answer 12

Omitting patient serum from the test mixture, omitting reagent from test mixture, under centrifugation, vigorous shaking

Question 13

False positive OR false negative errors

Answer 13

Incorrect labeling, addition of incorrect reagent, erroneously reading or interpreting results, inaccurately recording results, expired or improperly stored reagent

Question 14

Procedure format

Answer 14

1) Title, Purpose or principle, 2) specimen collection and preparation, 3) reagents, supplies, and equipment, 4) Quality control, 5) Procedural steps, 6) Reporting results, 7) Procedural notes - sources of error, limitations, clinical applications, 8) References

Question 15

Limits of detection

Answer 15

a measure of analytic sensitivity. The lowest concentration of analyte that can be detected in 95% of repeat measurements. Higher LoD misses more infected patients.

Question 16

Predictive value- pos

Answer 16

Positive indicates the number of patients with an abnormal test result who have the disease compared to all patients with an abnormal result

Question 17

Predictive value- neg

Answer 17

Negative PV indicates the number of patients with a normal test result who do not have the disease compared with all patients who have a normal result.