Quality Control Flashcards
(33 cards)
A gaussian distribution curve is usually
a. Rectangular
b. Bell shaped
c. Uniform
d. Skewed
B. Bell Shaped
The correlation coefficient
a. Indicates the strength of relationship in a linear regression.
b. Determines the regression type used to derive the slope and y-intercept.
c. Is always expressed as “b.”
d. Expresses method imprecision.
D. Expresses method imprecision.
Systematic error can best be described as consisting of
a. Constant and proportional error.
b. Constant error.
c. Proportional error.
d. Random error.
e. Syntax error.
a. Constant and proportional error.
Examples of typical reference interval data distribution
plots include all of the following except
a. ROC
b. Nonparametric
c. Parametric
d. Bimodal
a. ROC
A reference range can be verified by
a. Testing as few as 20 normal donor specimens.
b. Literature and vendor material review.
c. Using samples from previously tested hospital
patients.
d. Using pharmacy-provided plasmanate spiked
with target analyte concentrations.
a. Testing as few as 20 normal donor specimens.
Diagnostic specificity is the
a. Ability of a test to correctly identify the
absence of a given disease or condition.
b. Chance an individual does not have a given disease or condition if the test is within the reference interval.
c. Chance of an individual having a given disease or condition if the test is abnormal.
d. Ability of a test to detect a given disease or condition.
a. Ability of a test to correctly identify the
absence of a given disease or condition.
Interference studies typically use _______.
a. Hemolysed RBCs
b. Intralipids
c. Higly Icteric
d. AOTA
d. AOTA
Which Westgard rule detects random error.
a. 13s
b. 41s
c. 22s
d. 10x
a. 13s
The primary reason for implementing POCT
a. Reduced Testing cost
b. Enhanced outcomes of patient care
c. Lower central laboratory workload
d. use non-laboratorian analysts
b. Enhanced outcomes of patient care
Highest source of error in the Laboratory
a. Mislabeling
b. Patient Misidentification
c. Clerical Error
d. Pipetting
c. Clerical Error
Which are causes of Random Error
- Temperature of Analyzer
- Reagent Dispensing
- Instrument Instability
- Calibration Differences
a. 1 & 4
b. 2 & 3
c. 1, 2,3 & 4
d. 1, 2 and 3
d. 1, 2 and 3
Which are examples of Analytical Error
- Verbal reporting of results
- Oversight of Instruments
- Out of control QC
- Wrong assay performed
a. 2, 3, and 4
b. 3 and 4
c. 1, 2, and 3
d. 1 and 2
a. 2, 3, and 4
Which of the following quality control (QC) rules
would be broken 1 out of 20 times by chance alone?
A. 12s
B. 22s
C. 13s
D. 14s
A. 12s
Which of the following conditions is cause for
rejecting an analytical run?
A. Two consecutive controls greater than 2 s above
or below the mean
B. Three consecutive controls greater than 1 s above
the mean
C. Four controls steadily increasing in value but less
than ±1 s from the mean
D. One control above +1 s and the other below –1 s
from the mean
A. Two consecutive controls greater than 2 s above
or below the mean
One of two controls within a run is above +2s
and the other control is below –2s from the mean.
What do these results indicate?
A. Poor precision has led to random error (RE)
B. A systematic error (SE) is present
C. Proportional error is present
D. QC material is contaminated
A. Poor precision has led to random error (RE)
The term R4S means that:
A. Four consecutive controls are greater than ±1
standard deviation from the mean
B. Two controls in the same run are greater than
4s units apart
C. Two consecutive controls in the same run are
each greater than ±4s from the mean
D. There is a shift above the mean for four
consecutive controls
B. Two controls in the same run are greater than
4s units apart
A trend in QC results is most likely caused by: A. Deterioration of the reagent B. Miscalibration of the instrument C. Improper dilution of standards D. Electronic noise
A. Deterioration of the reagent
In most circumstances, when two controls within a
run are both greater than ±2s from the mean, what
action should be taken first?
A. Recalibrate, then repeat controls followed by
selected patient samples if quality control is
acceptable
B. Repeat the controls before taking any corrective
action
C. Change the reagent lot, then recalibrate
D. Prepare fresh standards and recalibrate
A. Recalibrate, then repeat controls followed by
selected patient samples if quality control is
acceptable
When establishing QC limits, which of the
following practices is inappropriate?
A. Using last month’s QC data to determine
current target limits
B. Exclusion of any QC results greater than ±2s
from the mean
C. Using control results from all shifts on which the
assay is performed
D. Using limits determined by reference laboratories
using the same method
B. Exclusion of any QC results greater than ±2s
from the mean
Which of the following plots is best for detecting all types of QC errors? A. Levy–Jennings B. Tonks–Youden C. Cusum D. Linear regression
A. Levy–Jennings
Which of the following plots is best for comparison of precision and accuracy among laboratories? A. Levy–Jennings B. Tonks–Youden C. Cusum D. Linear regression
B. Tonks–Youden
Which plot will give the earliest indication of a shift or trend? A. Levy–Jennings B. Tonks–Youden C. Cusum D. Histogram
C. Cusum
All of the following are requirements for a
QC material except:
A. Long-term stability
B. The matrix is similar to the specimens being
tested
C. The concentration of analytes reflects the clinical
range
D. Analyte concentration must be independent of
the method of assay
D. Analyte concentration must be independent of
the method of assay
What is the minimum requirement for performing QC for a total protein assay? A. One level assayed every 8 hours B. Two levels assayed within 8 hours C. Two levels assayed within 24 hours D. Three levels assayed within 24 hours
C. Two levels assayed within 24 hours
