QUALITY CONTROL AND QUALITY ASSURANCE Flashcards
At the end of the lesson, the learners should be able to:
1. discuss the basic elements of plating;
2. appreciate the importance of plating in enhancing food presentation; and
3. create a simple plated dish incorporating the five basic elements what are the main goal of quality control
to detect analytic errors
to prevent reporting of inaccurate test results
Important component in the operation of the clinical laboratory
quality control
our reporting of results are provided in quantitative set up which means it’s not reactive or non reactive nor positive or negative but rather a NUMERIC data
true or false
true
part of the overall goal of quality assurance
quality control
the parameters of quality control in every series of measurements
accuracy and precision
It is a system of ensuring ACCURACY and PRECISION in the
laboratory by including quality control reagents in every series
of measurements.
quality control
the procedure and the times of processing quality control in a day should be included on a book or a reference material called
sop or standards operating procedure
a sample we used for quality control is called
qc material or quality control material
a quality control material or qc materials must always resemble the ___
patient sample or serum
It is one component of the quality assurance system and is part
of the performance monitoring that occurs after a test has been
established.
quality control
SLDC means
Software Development Life Cycle
____ is a set of activities
for ensuring quality in
the processes by which
products are developed.
QA
__is a set of activities
for ensuring quality in PRODUCTS.
The activities
focus on identifying defects
in the ACTUAL PRODUCTS
PRODUCED.
QC
_ is to used follows
process & avoiding bugs
QA
__ is used to follow product testing for
quality avoiding bugs.
Quality Control
QA is Separate
Process
true or false
true
Quality Control is not part of
SDLC or QA
true or false
false
QA or QC
it will give confidence to you as you know completely the process
QA
QA or QC
____ gives expected results
Quality Control
QA or QC
it prevents defect rather than correcting it
QA
parameters of quality control
sensitivity
specificity
accuracy
precision or reproducibility
practicability
reliability
diagnostic sensitivity
diagnostic specificity
a parameter of quality control that 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
an accuracy value given by the manufacturer
assayed value
accuracy can be estimated by 3 types of studies, what are those?
recovery study
interference study
sample comparison study
___ study determines how much of the analyte can be identified in the sample
recovery study
this study determines if specific samples affect the laboratory tests such as hemolyze, turbid, icteric
interference study
this study is used to assess the presence of an error (inaccuracy) in the actual patient sample
sample comparison study
a study used to estimate accuracy in which it determines how much of the analyte can be identified in the sample
recovery study
a study used to estimate accuracy in which it determines if a specific compounds affect the laboratory tests like hemolysis, turbidity, ad icteric
interference study
a study used to estimate accuracy in which it is used to assess presence of error (inaccuracy) i actual patient sample
sample comparison study
a hemolyzed sample can result to a falsely (increase, decrease) result of a potassium
increase
It is the ability of an analytical method to give repeated results
on the same sample that agree with one another.
precision or reproducibility
Closeness of analyte result to each other
precision or reproducibility
what type of error can affect precision?
random error
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
It indicates the ability of the test to generate more true positive results and few false-negative.
diagnostic sensitivity
diagnostic sensitivity is a Screening tests that require ___ so that no case is missed.
high sensitivity
It is the ability of the analytical method to detect the proportion
of individuals WITH the disease
diagnostic sensitivity
what type of error can affect accuracy?
systematic error
formula of sensitivity
true positive divided by the sum of the quantity of true positive plus false negative
multiply them all to 100
[true positive/ (true positive + false negative) ] x 100
It is the 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 and false-positive
diagnostic specificity
a Confirmatory tests that require high specificity to be certain of the
diagnosis.
Diagnostic Specificity
Chance of an individual having a given disease or
condition if the test is abnormal
Positive predictive value (PPV)
Chance an individual does not have a given disease
or condition if the test is within the reference interval.
Negative predictive value (NPV)
It involves the analyses of control samples together with the
patient specimens.
Intralab Quality Control (Internal QC)
It detects changes in performance between the present
operation and the “stable” operation
Intralab Quality Control (Internal QC)
It is important for the daily monitoring of accuracy and precision
of analytical methods.
Intralab Quality Control (Internal QC)
It detects both random and systematic errors in a daily basis.
Intralab Quality Control (Internal QC)
It allows identification of analytic errors within a one-week
cycle.
Intralab Quality Control (Internal QC)
important for the daily monitoring of accuraty and precision.
Intralab Quality Control (Internal QC)
the initial control limits are established analyzing pool material in how many consecutive runs and reevaluated periodically
20 consecutive runs
It involves proficiency testing programs that periodically provide samples of unknown Concentrations to participating clinical laboratories.
Interlab Quality Control (External QC)
is the gold standard for cliinical laboratory external qc testing
Interlab Quality Control (External QC)
It is important in maintaining long-term accuracy of the
analytical methods.
Interlab Quality Control (External QC)
It is also used to determine state-of-the-art interlaboratory
performance.
Interlab Quality Control (External QC)
From reference laboratory or provided by the reference laboratory
Interlab Quality Control (External QC)
NEQAS - example of refernce lab
transcribe pls
National external quality assessment
schemes
what is the reference lab of cchm/biochem
lung center of the philippines
what is the reference lab of microbiology
research institute for tropical medicine
what is the reference lab of infectious diseases
san lazaro hospital
what is the reference lab of drug testing
east avenue medical center
A series of unknown samples are sent to the laboratory from
the reference laboratory or authorized program provider.
Conduct of the External QC Testing
Unknown samples must be tested by the laboratorians who
regularly perform analysis of patient
Conduct of the External QC Testing
Specimens using the same reagents and equipment for actual
patient specimens, and the results are submitted to the
program provider, preferably as soon as every analysis is done.
Conduct of the External QC Testing
to interpret the results of the proficiency testing
In external QC, difference of greater than ___ in the results
indicates that a laboratory is not in agreement with the rest of
the laboratories included in the program.
2SD
If in case a clinical laboratory failed to identify or resolve an
error or discrepancy in the test process, the facility is at risk of
continuous operation and may be recommended for closure.
true or false
true
to interpret the proficiency testing, we used ____
among all the hospitals in the vicinity that use the same equipment, techniques, reagent and reagents must be able to reach the standard value
peer mean
Name of the program for the proficiency testing
NEQAS - National external quality assessment scheme
The ultimate goal of ___ is to ensure our
clinicians that patient results are accurate.
proficiency testing
___ allows each laboratory to compare and
evaluate test results or outcomes with those laboratories that
use the same methods (reagents and equipment).
Proficiency testing
Data obtained from the proficiency testing can be used to
___, and also serve as
___ when investigating analytic error
continuously improve test performance; troubleshooting guide
3 Objectives of Quality Control
- To check the stability of the machine.
- To check the quality of reagents.
- To check technical (operator) errors
The accuracy of any assay depends on the ___,
how they are originally constituted and how they remain STABLE OVER TIME
control solutions
what are the 2 levels of control in cc
normal and abnormal
for immunoassay, what are the 3 controls used?
normal
high
low
To establish 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 how many days?
20 DAYS
For highly précised assays (with CV less than 1%) such as
BLOOD GASES, analysis for ____DAYS is adequate.
5 days
an example of substance we need to analyzed for 5 days
blood gases (PO, O2, pH, pCO2)
what is the standard limits of control
no greater than 2SD
Characteristics of an Ideal QC Material
- Resembles human sample.
- Inexpensive and stable for long periods.
- No communicable diseases.
- No matrix effects/known matrix effects.
- With known analyte concentrations (assayed control).
- Convenient packaging for easy dispensing and storage.
general characteristics of QC
commercially prepared
assayed (data are given by the manufacturer)
liquid form
lyophilized (powdered form)
powdered form, perform reconstitution by simple
addition of distilled water
Lyophilized
The test method must be compared always with a method of
acceptable accuracy such as ___
Reference method
Reference method is also known as
Gold standard
what is the glucose reference method
hexokinase method
transcribe CLIA
Clinical Laboratory Improvement Amendments (CLIA)
It is recommended by Westgard et al and Clinical Laboratory
Improvement Amendments (CLIA) that ___ samples be
run by each method in duplicate on the same day over ___, ideally within ___hours, to determine its accuracy and
precision.
40 to 100; 8 to 20 days; 4
according to westgard and clia, if only 40 samples will be measured, daily analysis of in duplicate of 2-5 specimens should be followed for how many days?
at least 8 days
the rationale for performing repeated assays us to
detect random errors that affect precision
the most important characteristics of method evaluation is to
determine if the total error (random+systematic error) is less than the allowable error
Are errors encountered in the collection, preparation and measurement of samples, including transcription and
releasing of laboratory results.
variations
what are the types of errors
random error
systematic error
clerical error
allowable error
pre-analytical error
analytical error
post-analytical error
a type of error wherein it is present in all measurements; it is due to chance.
random error
It is a type of error which varies from sample to sample
random error
It is the basis for varying differences between repeated
measurements - VARIATIONS IN TECHNIQUE.
RANDOM ERROR
It is due to instrument, operator and environmental conditions
(variations in techniques) such as pipetting error, mislabeling
of samples, temperature fluctuation, and improper mixing of
sample and reagent.
RANDOM ERROR
an error affectingprecision
random error
It is an error that influences observations consistently in one
direction (constant difference).
Systematic Error
It is detected as either positive or negative bias - often related
to calibration problems, deterioration of reagents and control
materials, improperly made standard solutions, contaminated
solutions, unstable and inadequate reagent blanks, leaky ion
selective electrode (ISE), failing instrumentation and poorly
written procedures.
systematic error
It is a measure of the agreement between the measured quantity and the true value. (accuracy )
systematic error
an error affecting accuracy
systematic error
what are the 2 types of systematic error
constant and proportional/slope/percent error
a type of systematic error that refers to a difference between the target value and the
assayed value.
Constant Error
a type of systematic error that is independent of sample concentration.
constant error
a type of systematic error that exists when there is a continual difference between the
comparative method and the test method regardless of the
concentration
constant error
a type of systematic error that results in greater deviation from the target value due to higher
sample concentration.
Proportional / Slope/ Percent Error
It exists when the difference between the test method and the
comparative method values is proportional to the analyte
concentration
Proportional / Slope/ Percent Error
It is the highest frequency of errors occurs with the use of handwritten labels and request forms
clerical error
Manmade error
clerical error
___% of errors are non-laboratory personnel
29%
the most frequent pre analytical errors are
improperly filling of the sample tube
placing the specimens in the wrong containers or preservatives
selecting the incorrect test
is the most error free means of requesting laboratory tests
online computer input
most lab errors are in
pre and post analytical stages
Indicators of analytic performance:
internal QC,
proficiency testing,
accreditation (DOH),
quality assurance monitoring
laboratory utilization
To study imprecision or random error, how many control
solutions are run twice a day in a 10- to 20-day period
2 control solutions
It is based on the quantity of error that will negatively affect
clinical decisions.
Allowable Error (E.)
The total error (random, proportional, constant and systematic
error) must be less than the E. or fixed limits for a method to be
considered acceptable.
Allowable Error (E.)
The determination of whether long-term precision is sufficient
is based on the total imprecision being less than 1/3 of the
__
Allowable Error (E.)
what are the 3 phases of laboratory testing
pre-analytical
analytical
post analytical
pre-analytic lab testing comprises
patient/client prep sample collection
sample transport
sample receipt and accessioning
analytic lab testing comprises
quality control testing
personnel competency test evaluation
post - analytic lab testing comprises
reporting
record keeping
be familiarize with the pre-analytical errors
- Incorrect patient identification
- Improper patient preparation – barcoded
- Incorrect specimen collection
- Mislabeled specimen
- Incorrect order of draw
6. Incorrect used of tubes for blood collection - Incorrect anticoagulant to blood ratio (short draw)
- Improper mixing of blood and anticoagulant
9. Incorrect specimen preservation - Mishandled specimen (transport and storage)
-
Incorrectlyinterpreted/orderedlaboratory test– requests
of doctors should always computerize. - Incomplete centrifugation
- Incorrect data log-in
be familiarize with the analytical errors
- Incorrect sample and reagent volume
- Incorrect incubation of solution
- Equipment/instrument malfunction
- Improper calibration of equipment/calibration error
be familiarize with the post-analytical errors
- Unavailable or delayed laboratory results
- Long turnaround time
- Incomplete laboratory results
- Wrong transcription of the patient’s data and laboratory results
- Missing laboratory results
- Laboratory results submitted to the wrong physician/doctors
who did not request for the lab test
is the combination of Six Sigma methodology
and Lean principles.
lean six sigma methodology
the goal of __ is to 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 methodology
improving the performance by reducing errors
lean six sigma
to eliminate the WASTE, such as streamlining a
process to reduce wait times or modifying a process to reduce cost.
lean principles work
reduce error -
reduce waste -
reduce error - six sigma
reduce waste - lean
Lean improvement projects start with organizing the areas
using 6S ___
transcribe 6S
(Set, Sort, Shine, Standardize, Sustain, and Safety )
The five phases allow for the identification of the root cause for
error and waste
Process Improvement (DMAIC)
(Define, Measure, Analyze, Improve, Control)
transcribe DMAIC
(Define, Measure, Analyze, Improve, Control)
Applications of Lean Six Sigma are now being applied to all
aspects of the laboratory and the health care system as a
whole to ____
- A universally accepted framework for QI
- Common language throughout the organization
- A checklist to guide the process
- Control measures to sustain improvements and offer long-term monitoring
Seek to quantitatively measure the amount of error or variation
that occurs within a system.
Six Sigma Metrics
amount of error or variation// sx sigma metrics are measured using
Defects (errors) per million opportunities
(DPMO)
are used to compare the means or standard deviations of two groups of data
inferential statistics
is used to determine whether there is a statistically significant difference between the standard deviations of the two group of data
f test
is the value of the observation that divides the observation into 2 groups, each containing equal number of observations ;
median
it is used to describe data with2 centers
mode
the simplest expression of spread or distribution
range
it is the difference between the highest and the lowest score in data
range
is the difference between the balue of a data point and the mean value divided by the group’s SD
standard deviation
it is utilized for proficiency testing or standardization of laboratories
standard deviation
also known as the Z score
standard deviation
is used to determine whether or not there is statistically significant difference between the means of two groups of data
t test
are use to determine the types and quantity of error that a method has and to decide whether the test is still valid or unacceptable to make clinical decisions
statistical analyses
example of parametric statistics
calculation of mean, standard deviation, and variance
three measures of spread and distribution
range
standard deviation
coeffucient of variation
it describes the distribution of all values around the mean
SD
is best utilized if the distribution of the values is normal
SD
represents the average distance from the center of the data and every value in the data set
SD and variance
The CV analyzers described as having reproducible test results can be lower than how many percent
1%
is used to analyze precision data to give estimates of the within-in run, between-run, and total imprecision
ANOVA
