QUALITY MANAGEMENT SYSTEM IN CC LAB Flashcards
it involves systematic monitoring of analytic processes to detect analytic errors to prevent reporting of inaccurate results
Quality control
parameters of quality control
accuracy and precision
is a standardized procedure and
practice contributing to the overall quality
of laboratory test results.
Laboratory Quality Management System
is a set of activities for ensuring quality in the process which products are developed
Quality assurance
Set of activities for ensuring quality in products, it focuses on identifying defects in the actual products produced
Quality control
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 analyte of the interest
Specificity
It is the nearness or closeness of the assayed value to the true or target
value.
Accuracy
Accuracy is estimated using 3 types of studies:
recovery, interference and
patient sample comparison.
determines how much of the analyte can be
identified in the sample;
Recovery study
Came from the manufacturer of reagent or machine
assayed value
determines if specific compounds affect the
laboratory tests like hemolysis, turbidity and icteric;
Interference 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:
: effect of a compound on the accuracy of detection of a particular
analyte
❑ Interference
substance that cause interference.
❑ Interferents:
body component (eg. Fluid, urine etc.) in which the analyte is to be
measured
❑ Matrix:
Determination of Imprecision and Inaccuracy
A. – will show whether the method is able to accurately measure
and detect the analyte
Recovery study
it will determine if specific compounds affect determination of
analyte concentration
B. Interference study –
– it is used to estimate systemic error in actual patient
samples.
C. comparative study
- It is the
ability of an analytical method to give
repeated results on the same sample that
agree with one another. (closeness of analyte result to each 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
- It is the ability of the analytical method to
detect the proportion of individuals with
the disease. - It indicates the ability of the test to generate
more true-positive results and few falsenegative. - Screening tests require high sensitivity so
that no case is missed.
Diagnostic sensitivity
– Diagnostic Sensitivity (%)=
True positive/(TP + FN) x 100
- It is the ability of the analytical method
to detect the proportion of individuals
without the disease. - It reflects the ability of the method to
detect true-negatives with very few falsepositives. - Confirmatory tests require high
specificity to be certain of the diagnosis.
Diagnostic specificity
– Diagnostic Specificity (%)=
True negative/(TN + FP) x 100
Accuracy is affected by
Systematic error
Precision is affected by
Random error
Ability of a test to detect a given disease or condition
Diagnostic sensitivity
Ability of a test to correctly identify the absence of a given disease or condition
Diagnostic specificity
Chance of an individual having a given disease or condition if the test is abnormal
Positive predictive value
Chance an individual does not have a given disease or condition if the test is within the reference interval
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)
NEQAS
national external quality assessment scheme
Reference lab:
CC/Biochem
Microbiology:
Infectious diseases:
Drug testing:
CC/Biochem: Lung center of the Philippines
Microbiology: Research Institue for tropical medicine
Infectious diseases: San Lazaro
Drug testing: East Avenue Medical Center
Objectives of Quality Control:
❑1. To check the stability of the machine.
❑2. To check the quality of reagents.
❑3. To check technical (operator) errors.
The accuracy of any assay depends on the control
solutions, how they are originally constituted and how
they remain stable overtime.
* General chemistry assays used 2 levels of control
solutions, while immunoassays used 3 levels.
* 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 20 days.
* For highly précised assays (with CV less than 1%) such
as blood gases, analysis for 5 days is adequate.
Control solution(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
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.
Lyophilized
Powder
The test method must be compared always with a
method of acceptable accuracy such as____________.
Reference method/gold standard
It is recommended by ___________ & _________that
40 to 100 samples be run by each method in
duplicate on the same day over 8 to 20 days,
ideally within 4 hours, to determine its accuracy
and precision.
Westgard et al and Clinical
Laboratory Improvement Amendments (CLIA)
True or false: If only 40 samples will be measured, daily analysis in
duplicate of 2 to 5 specimens should be followed for
at least 8 days
True
- 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. - It is a type of error which varies from sample to sample
- It is the basis for varying differences between
repeated measurements - variations in technique. - 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. - PRECISION
- Random Error
- It is an error that influences observations consistently in one
direction (constant difference). - 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. - It is a measure of the agreement between the measured
quantity and the true value- ACCURACY
- Systematic Error
Types of Systematic error
a. Constant Error,
b. Proportional/Slope/Percent Error
- it refers to a difference between the target value and
the assayed value.
✓ it is independent of sample concentration.
✓ it exists when there is a continual difference between the comparative
✓ method and the test method regardless of the concentration.
❑ a. Constant Error
- it results in greater deviation
from the target value due to higher sample concentration.
✓ it exists when the difference between the test method and the
comparative method values is proportional to the analyte concentration.
❑ b. Proportional/Slope/Percent Error
- It is the highest frequency of clerical errors occurs with
the use of handwritten labels and request forms.
- Clerical Error
True or false: 25% of errors comes from non laboratory personnels
False
29%
- It is based on the quantity of error that will negatively affect
clinical decisions. - 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. - The determination of whether long-term precision is
sufficient is based on the total imprecision being less
than 1/3 of the allowable error.Allowable Error (E.) - It is based on the quantity of error that will negatively affect
clinical decisions. - 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 (X/X) of the allowable error.
1/3
everything we do before the actual experimentation/testing of the sample
Pre-analytical Errors:
Anything that has to do with the actual testing of the sample
Analytical
Pertaining to generating/reporting of the result
Post analytical
is the combination of Six Sigma
methodology and Lean principles.
it is a management strategy
developed by Motorola, Inc. in the 1980s
*
Lean Six Sigma
Goal of six sigma:
To identify and eliminate the cause of defects and errors
- to eliminate the waste,
such as streamlining a process to reduce wait times
or modifying a process to reduce cost
- Lean principles work
Modified true or false:
This is usually a 3- to 5-day project to reduce
waste, such as turnaround times, wait times,
flow or cycle times, and causes that can be
seen by observation.
* Lean improvement projects start with
organizing the areas using 5S (Set, Sort,
Shine, Standardize, Sustain, and Safety has
been added to make it 6S).
Both are true
true or false Lean Six Sigma uses a problem–cause–
solution methodology to improve any process
through waste elimination and variation
reduction.
true
DMAIC
Define, Measure, Analyze, Improve,
Control) methodology
DPMO
Defects per million opportunities
