This document discusses quality control in laboratories. It defines key terms like quality assurance, quality assessment, total quality management, and continuous quality improvement. It describes factors that can affect quality like pre-analytical, analytical, and post-analytical variables. The importance of standard operating procedures, proficiency testing, and documenting quality control procedures is emphasized. Maintaining accurate and precise results through internal quality control using control charts and Westgard rules is also outlined.
2. QUALITY
• Doing the right thing right, the first
time and every time.
• Is fitness for use “Juran”: a service
which is free from deficiencies and
meets customers need
• It’s invisible when GOOD & impossible
to ignore when BAD
• Dimensions:
Appro-
priate-
ness
Time-
liness
Avail-
ability
Comp-
etency
Contin-
uity
Effec-
tive-
ness
Effic-
acy
Effic-
iency
Preven-
tion/
Early
Detec-
tion
Respe-
ct and
caring
Safety
3. QUALITY
• Total Quality Management
(TQM): a process of customer-
driven quality improvement by
having the lab monitor, its work
to detect deficiencies &
subsequently correct them to
provide value.
• Continuous Quality Improvement
(CQI): It’s a management
process or approach to
continuous improvement of
processes of providing
healthcare services to meet the
needs of patients.
4. QUALITY
• Quality Assurance (QA): It’s the overall
program that ensures that the final results
reported by the laboratory are correct. It
is concerned with much more: that the
right test is carried out on the right
specimen, and that the right result and
right interpretation is delivered to the
right person at the right time.
• Quality Assessment (proficiency testing):
It is a challenge to the QA and QC
programs. It may be external or internal.
It’s used to determine the quality of the
results generated by the laboratory.
6. Improvement in quality leads to
reduction in costs
Quality
Costs
Costs of
conform-
ance
Prevention
costs
Appraisal
costs
Costs of
nonconf-
ormance
Internal
failure costs
External
failure costs
7. QUALITY
GOOD QUALITY
Support provision of high
quality health-care
Generate confidence in
lab results
Ensure credibility of lab
POOR QUALITY
Inappropriate action
(Over-investigation,
Over-treatment,
Mistreatment)
Loss of credibility of
laboratory
Delayed action
Legal action
8. VARIABLES THAT AFFECT THE
INTERNAL QUALITY
•
Outside laboratory
Within laboratory
Sample
handling
Patient
preparation
Requisition
Sample
receivingSample
Collection
Sample
Transport
Patient
Doctor
Analysis
Reports
Results
9. PRE-ANALYTICAL
• Patient and specimen identification
and labelling
• Patient preparation
• Specimen collection, storage and
transportation
• Specimen quantity
• Mismatch of sample
10. ANALYTICAL
• Internal quality control (IQC)
It’s used on daily basis in the decision
to accept or reject results of patients
samples & enables the lab to describe
and monitor the quality of its work.
• External quality assessment (EQA)
It permits a comparison of quality
between laboratories and It is used to
confirm results of IQC.
12. STANDARD OPERATING
PROCEDURE (SOP)
• It’s written instructions
intended to document how
to perform a routine activity.
• High reliability organization
(HROs) rely on standard
operating procedure to
ensure consistency and
quality in their results.
13. POST ANALYTICAL
• Right reporting
• Right patient
• Right interpretation
• Right turn-around time (TAT)
14. ACCURACY VS. PRECISION
• Accuracy - how close a measurement is to the
accepted value
(ACCURATE = CORRECT)
• Precision - how close a series of measurements
are to each other
(PRECISE = CONSISTENT)
• Quality Control is used to monitor both the precision
and the accuracy of the assay in order to provide
reliable results.
15. ICQ PROCEDURES
• A stable control material which mimics
patient’s sample is analyzed (day to
day)•
• Individual measurements are plotted
on a control chart (Levey Jennings
charts)•
• Evaluation whether measurement is “in
control” (Westgard multi-rules)
16. LEVEY JENNINGS CONTROL
CHART (PLOTTING QC RESULT )
• Mean and SD of QC
material
(manufacturer)
• Y-axis: control
value
X-axis: time of run
• Most auto-analyzers
plot the charts,
otherwise they should
be drawn manually. 80
85
90
95
100
105
110
115
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Mean
+1SD
+2SD
+3SD
-1SD
-2SD
-3SD
Day
17. LEVEY JENNINGS CONTROL
CHART (PLOTTING QC RESULT )
• Ideally should have control values clustered about the mean
with little variation in the upward or downward direction
• Imprecision = large amount of scatter about the mean. Usually
caused by errors in technique
• Inaccuracy = may see as a trend or a shift, usually caused by
change in the testing process
• Random error = no pattern. Usually poor technique,
malfunctioning equipment.
• Review charts at defined intervals, take necessary action, and
document
18. WESTGARD RULES (EVALUATING
QC RESULTS )
• It Detects whether results are “in
control” or not.
• It Detects the type of laboratory
error.
• It’s used to diminish the false
rejection rate without
compromising quality.
19. RANDOM ERROR, RE, OR
IMPRECISION
• It is described as an error that can be
either positive or negative, whose
direction and exact magnitude cannot
be predicted, where the distribution of
results when replicate measurements
are made on a single specimen.
• Usually, due to error in pippetting
20. SYSTEMATIC ERROR, SE, OR
INACCURACY
• It is an error that is always in one
direction, displacing the mean of the
distribution from its original value.
• In contrast to random errors,
systematic errors are in one direction
and cause all the test results to be
either high or low.
• Usually, due to error in calibration.