QA AND QC Flashcards
medical laboratory requires quality in all steps
Quality management system
Quality management systems: Laboratory functions that require quality practices include
Environment
Quality procedures
Record keeping
Expert human resource
Quality reagents
Quality equipment and instruments
standardized procedure and
practice contributing to the overall quality
of laboratory test results.
Laboratory quality management system
According to ________, the quality of a testing
result does not depend on a single step. But
instead, it requires quality in individual
processes, resources, and overall
organizational structure.
LQMS (laboratory quality management system)
is an international standard that
specifies the requirements for quality and
competence in medical laboratories
ISO 15189: 2022
This standard guides the development of the
laboratory’s quality management system, technical
solutions, and administrative sections that are the main
factor for a laboratory’s functioning.
ISO 15189: 2022
focused on providing confidence
that quality requirements will be fulfilled
Quality assurance
ensuring that a specified quality of product is
achieved and maintained.
Quality assurance
Important component in the operation of
the clinical laboratory
Quality control
Involves systematic monitoring of analytic
processes to detect analytic errors and to
prevent reporting of inaccurate test results
Quality control
It is a system of ensuring accuracy and precision in the laboratory by including quality control
reagents in every series of measurements
Quality control
It is a process of ensuring that analytical results
are correct by testing known samples that resemble patient samples
Quality control
QA IS
Proactive
Process oriented
Training
Documentation
Full team
Audit
Creation
QC IS
Lab testing
Product oriented
Inspection
Verification
Reactive
Evaluate feedback
Reports
QA & QC
Release high quality product
Improve processes procedures
Gain trust of customer
Reduce costs
Find issues before major problems
It is the ability of an analytical method to measure the smallest concentration of the analyte of interest.
Sensitivity
It is the ability of an analytical
method to measure only the analyte of interest.
Specificity
It is the nearness or closeness of the assayed value to the true or target value
Accuracy
3 types of studies: accuracy
Recovery, interference, patient sample comparison
determines how much of the analyte can be identified in the sample;
Recovery study
determines if specific compounds affect the laboratory tests like hemolysis, turbidity and icteric
Interference study
study is used to assess presence of error (inaccuracy) in actual patient sample
Sample comparison study
ability of an analytic test to measure a known amount of analyte; a
known amount of analyte is added to real sample matrices
Recovery
body component (eg. Fluid, urine etc.) in which the analyte is to be measured
Matrix
effect of a compound on the accuracy of detection of a particular analyte
Interference
substance that cause interference.
Interferent
Study will show whether the method is able to accurately measure
and detect the analyte
Recovery study
Study will determine if specific compounds affect determination analyte concentration
Interference study
it is used to estimate systemic error in actual patient samples.
Comparative study
It is the
ability of an analytical method to give
repeated results on the same sample that
agree with one another
Precision or reproducibility
It is the degree by which a
method is easily repeated.
Practicability
It is the ability of an analytical method to maintain accuracy and precision over an extended period of time during which equipment, reagents and personnel may change.
Reliability
ability of the analytical method to
detect the proportion of individuals with
the disease.
Diagnostic sensitivity
It indicates the ability of the test to generate
more true-positive results and few false-
negative.
Diagnostic sensitivity
Test used in diagnostic sensitivity require high sensitivity so
that no case is missed.
Screening test
ability of the analytical method
to detect the proportion of individuals
without the disease.
Diagnostic specificity
It reflects the ability of the method to
detect true-negatives with very few false-
positives.
Diagnostic specificity
Test used in diagnostic specificity require high
specificity to be certain of the diagnosis.
Confirmatory testing
The likelihood/probability of the test
Predictive value
the percentage of people with
positive test results who have the disease
Positive predictive value
the percentage of people with
negative test results who do not have the disease
Negative predictive value
- It involves the analyses of control samples together with the patient specimens.
- It detects changes in performance between the present operation and the “stable” operation.
- It is important for the daily monitoring of accuracy and precision of analytical methods.
-It detects both random and systematic errors in a
daily basis. - It allows identification of analytic errors within a
one-week cycle.
Intralab quality control (internal qc)
• It involves proficiency testing programs
that periodically provide samples of
unknown concentrations to participating
clinical laboratories.
• It is important in maintaining long-term
accuracy of the analytical methods.
• It is also used to determine state-of-the-art
interlaboratory performance.
Interlab quality control (external QC)
Gold standard aka
Confidence limit
Objectives of Quality Control:
- To check the stability of the machine.
- To check the quality of reagents.
- To check technical (operator) errors.
General chemistry assays used 2 levels of control solutions
Normal control and abnormal control
immunoassays used 3 levels
Normal
High
Low
statistical quality control on a new instrument or on new lot numbers of control materials,
the different levels of control material must be
analyzed for ____ day
20 day
For highly précised assays (with CV less than 1%) such as blood gases, analysis for _____ day
5 day
Are errors encountered in the collection,
preparation and measurement of samples,
including transcription and releasing of
laboratory results.
Variations
It is present in all measurements; it
is due to chance.
Random error
It is an error that influences observations consistently in one
direction (constant difference).
Systemic errors
it refers to a difference between the target value and the assayed value
Constant error
it results in greater deviation from the target value due to higher sample concentration.
Proportional/percent/ slope error
It is the highest frequency of clerical errors occurs wit the use of handwritten labels and request forms.
Clerical error
It is based on the quantity of error that will negatively affect
clinical decisions.
Allowable error (E.)
Replication study
Random error
Recovery study
Proportional study
Interference study
Constant study
Comparison of methods
Systemic study
Replication and comparison
Total error
is the combination of Six Sigma
methodology and Lean principles.
Lean Six Sigma
The Six Sigma business management strategy
developed by
Motorola Inc. 1980s
seeks to improve the performance of
a process by identifying and eliminating
causes of defects and errors, resulting in
eliminating variation in the process.
Lean six sigma
to eliminate the waste,
such as streamlining a process to reduce wait times
or modifying a process to reduce cost
Lean principle
they are being increasingly used to reduce
error (Six Sigma) and waste (Lean) within the
health care system.
LSS (lean six sigma)
Examples of six sigma projects included in our laboratory organization have included
Reducing billing error in lab
Reducing blood waste in BB
Lean used to measure
5S (set, sort, shine, standardize, sustain)
Or 6S (safety)
Six sigma used to measure
DMAIC ( define, measure, analyze, improve, & control)
Seek to quantitatively measure the amount of error or variation that occurs within a system
Six sigma metrics
ACCURACY: ATM means
Accuracy is T test comparing mean
PRECISION: SPF means
Precision is F test comparing standard deviation
Six sigma metrics used to measure
Defects (errors) per million opportunities (DPMO).
