FUNDAMENTALS OF URINE AND
BODY FLUID ANALYSIS
5TH EDITION
AUTHOR(S)NANCY A. BRUNZEL
TEST BANK
1
Reference
Ch. 1 — Quality Assessment — Analytical Quality Control
(Levey-Jennings / Westgard)
Stem
A urinalysis technologist runs daily internal QC for a dipstick
analyzer. The Levey-Jennings chart for the glucose control
shows values drifting upward over 10 consecutive days but still
,all inside ±2 SD. The analyzer’s multi-rule monitor flagged no
Westgard rule violations. Which is the best laboratory action?
A. Continue routine testing because values remain within ±2 SD.
B. Initiate preventive maintenance and recalibrate the glucose
channel before next shift.
C. Replace the control material immediately and re-run QC; if
values persist, send instrument for repair.
D. Reduce run frequency of the control to once every other day
to conserve reagents.
Correct answer
B
Rationales
Correct (B): A steady upward drift within ±2 SD suggests a
systematic bias developing; preventive maintenance and
recalibration address instrument bias before it crosses control
limits. Acting now preserves analytic accuracy and prevents
future QC rule violations.
Incorrect (A): Remaining within ±2 SD does not exclude
progressive systematic error; passive continuation risks
reporting biased patient results.
Incorrect (C): Replacing control material may be reasonable if
control integrity is suspected, but systematic drift across days
more often indicates the instrument or reagent, so
recalibration/maintenance is the higher-value first step.
Incorrect (D): Reducing QC frequency undermines quality
assurance and risks missing further drift; not acceptable.
,Teaching Point
Trend within limits can indicate developing bias — investigate
early.
Citation
Brunzel, N. A. (2023). Fundamentals of Urine and Body Fluid
Analysis (5th ed.). Ch. 1.
2
Reference
Ch. 1 — Quality Assessment — Precision versus Accuracy
Stem
A lab validating a centrifuge reports that repeated urine specific
gravity measurements (refractometer) on the same pooled
specimen show low scatter (SD small) but the mean is 0.010
units higher than a reference laboratory’s mean. Which
interpretation and action are most appropriate?
A. The method is accurate but imprecise; increase replicates to
improve precision.
B. The method is precise but biased (inaccurate); perform
method comparison and recalibrate.
C. Both accuracy and precision are acceptable; no action
required.
D. The specimen pooled sample is degraded; recollect and
rerun.
, Correct answer
B
Rationales
Correct (B): Low scatter indicates good precision; a consistent
offset vs reference indicates bias (inaccuracy). Method
comparison and recalibration or adjustment of calibration curve
are appropriate to correct bias.
Incorrect (A): Precision is good, not poor; increasing replicates
won’t correct a systematic bias.
Incorrect (C): A consistent difference from reference shows
inaccuracy that requires correction.
Incorrect (D): Degradation would usually increase variability or
change mean unpredictably, not produce a consistent offset
compared to reference.
Teaching Point
Precision ≠ accuracy; precision with offset = systematic bias
needing calibration.
Citation
Brunzel, N. A. (2023). Fundamentals of Urine and Body Fluid
Analysis (5th ed.). Ch. 1.
3
Reference
Ch. 1 — Quality Assessment — Proficiency Testing (External QC)
BODY FLUID ANALYSIS
5TH EDITION
AUTHOR(S)NANCY A. BRUNZEL
TEST BANK
1
Reference
Ch. 1 — Quality Assessment — Analytical Quality Control
(Levey-Jennings / Westgard)
Stem
A urinalysis technologist runs daily internal QC for a dipstick
analyzer. The Levey-Jennings chart for the glucose control
shows values drifting upward over 10 consecutive days but still
,all inside ±2 SD. The analyzer’s multi-rule monitor flagged no
Westgard rule violations. Which is the best laboratory action?
A. Continue routine testing because values remain within ±2 SD.
B. Initiate preventive maintenance and recalibrate the glucose
channel before next shift.
C. Replace the control material immediately and re-run QC; if
values persist, send instrument for repair.
D. Reduce run frequency of the control to once every other day
to conserve reagents.
Correct answer
B
Rationales
Correct (B): A steady upward drift within ±2 SD suggests a
systematic bias developing; preventive maintenance and
recalibration address instrument bias before it crosses control
limits. Acting now preserves analytic accuracy and prevents
future QC rule violations.
Incorrect (A): Remaining within ±2 SD does not exclude
progressive systematic error; passive continuation risks
reporting biased patient results.
Incorrect (C): Replacing control material may be reasonable if
control integrity is suspected, but systematic drift across days
more often indicates the instrument or reagent, so
recalibration/maintenance is the higher-value first step.
Incorrect (D): Reducing QC frequency undermines quality
assurance and risks missing further drift; not acceptable.
,Teaching Point
Trend within limits can indicate developing bias — investigate
early.
Citation
Brunzel, N. A. (2023). Fundamentals of Urine and Body Fluid
Analysis (5th ed.). Ch. 1.
2
Reference
Ch. 1 — Quality Assessment — Precision versus Accuracy
Stem
A lab validating a centrifuge reports that repeated urine specific
gravity measurements (refractometer) on the same pooled
specimen show low scatter (SD small) but the mean is 0.010
units higher than a reference laboratory’s mean. Which
interpretation and action are most appropriate?
A. The method is accurate but imprecise; increase replicates to
improve precision.
B. The method is precise but biased (inaccurate); perform
method comparison and recalibrate.
C. Both accuracy and precision are acceptable; no action
required.
D. The specimen pooled sample is degraded; recollect and
rerun.
, Correct answer
B
Rationales
Correct (B): Low scatter indicates good precision; a consistent
offset vs reference indicates bias (inaccuracy). Method
comparison and recalibration or adjustment of calibration curve
are appropriate to correct bias.
Incorrect (A): Precision is good, not poor; increasing replicates
won’t correct a systematic bias.
Incorrect (C): A consistent difference from reference shows
inaccuracy that requires correction.
Incorrect (D): Degradation would usually increase variability or
change mean unpredictably, not produce a consistent offset
compared to reference.
Teaching Point
Precision ≠ accuracy; precision with offset = systematic bias
needing calibration.
Citation
Brunzel, N. A. (2023). Fundamentals of Urine and Body Fluid
Analysis (5th ed.). Ch. 1.
3
Reference
Ch. 1 — Quality Assessment — Proficiency Testing (External QC)
