Statistics in Clinical Chemistry and Quality Control

Question 0

Used with 2 or 4 control measurements per run

Answer 0

Westgard Rules

Question 1

Limited number of values

Answer 1

Categories

Question 2

Sum of all results divided by the number of results

Answer 2

Mean

Question 3

Amount of variation

Answer 3

Coefficient of variation

Question 4

Protein in urine

Answer 4

Ordinal scale

Question 5

Uses a single criterion or single set of control limits

Answer 5

Single-rule Quality Control

Question 6

Value that occurs most frequently in the data set

Answer 6

Mode

Question 7

Locator

Answer 7

Finds a requested percentile

Question 8

Warning rule to trigger careful inspection of the control data in Westgard multirule Quality Control

Answer 8

1(2s)

Question 9

Things we measure and count

Answer 9

Variables

Question 12

Variables can take on values in a quantitative range with defined differences between points

Answer 12

Interval scale

Question 12

50th percentile

Answer 12

Median

Question 12

Reject when 10 consecutive control measurements fall on one side of the mean

Answer 12

10(x) violation

Question 13

Probability that the true value falls into a category

Answer 13

Confidence interval

Question 13

Lowest value that an assay can reliably detect

Answer 13

Sensitivity

Question 14

Reject when 2 consecutive control measurements exceed the same +/- 2s control limit

Answer 14

2(2s) violation

Question 18

Accuracy is tested by ______ and ______.

Answer 18

Assaying patient specimens

Assaying interlaboratory survey materials with known values

Question 19

Analytic specificity is characterized by _____ and _____.

Answer 19

Determination of interferences

Non-specific responses to other analytes

Question 20

Ability to measure only the sought for analyte

Answer 20

Analytic specificity

Question 21

Uses a combination of decision criteria

Answer 21

Multirule Quality Control

Question 22

Scale with specific values but without equivalent distances between categories

Answer 22

Ordinal scale

Question 23

Control rule when the control limits are set as the mean +/- 3s

Answer 23

1(3s)

Question 24

Extent of random variation

Answer 24

Standard deviation

Question 25

Decision criteria

Answer 25

Control rules

Question 26

Variables can take on a limited number of values

Answer 26

Nominal scale

Question 27

Chart with control limits mean +/- 2s or mean +/- 3s

Answer 27

Levey-Jennings Chart

Question 28

Spread of data in which elements are distributed symmetrically around the mean

Answer 28

Gaussian distribution

Question 30

Reject when 1 control measurement in a group exceeds the mean + 2s and another exceeds the mean - 2s

Answer 30

R(4s)

Question 31

4(1s) violation rejects

Answer 31

when 4 consecutive control measurements exceed the same mean +/- 1s control limit

Question 39

The ability to correctly detect and quantify and analyte

Answer 39

Accuracy

Question 41

Precision is

Answer 41

the reproducibility of an assay