This document discusses quality control in clinical laboratory testing. It emphasizes that quality control is essential to provide reliable diagnostic reports and cost-effective patient care. Quality control involves monitoring precision, accuracy, and sources of variation through internal quality control, external quality assessment, and statistical analysis of control values using tools like control charts and Westgard rules. The goal is to minimize laboratory errors and reliably distinguish pathological variations in patient samples.
Quality in clinical laboratory is a continuous journey of improving processes through team work, innovative solutions, regulatory compliance with final objective to meet the evolving needs of clinicians & patients.
A routine session on quality assurance practice in a medical laboratory to sensitize and provide basics to those interested in working in a medical testing laboratory.
This is a series of notes on clinical pathology, useful for postgraduate students and practising pathologists. It covers all internal and external quality control techniques. The topics are presented point wise for easy reproduction.
Quality in clinical laboratory is a continuous journey of improving processes through team work, innovative solutions, regulatory compliance with final objective to meet the evolving needs of clinicians & patients.
A routine session on quality assurance practice in a medical laboratory to sensitize and provide basics to those interested in working in a medical testing laboratory.
This is a series of notes on clinical pathology, useful for postgraduate students and practising pathologists. It covers all internal and external quality control techniques. The topics are presented point wise for easy reproduction.
In the continuous quality journey, Controlling laboratory Errors is an integral part & focusing on analytical, post-analytical process is the first step. Developing a reporting culture followed by thorough analysis and implementation of appropriate corrective, preventive actions is required.
Recently ISO 15189:2022 have become available. This would help laboratories set up processes which would yield reproducible results and improve the quality of work.
Quality control, or QC for short, is a process by which entities review the quality of all factors involved in the production. ISO 9000 defines quality control as "A part of quality management focused on fulfilling quality requirements"
This presentation gives a brief idea of Quality control and how to execute it.
Internal quality control (IQC) in coagulation labAnkit Raiyani
In the haematology laboratory it is essential to ensure that the right test is carried out on the right specimen and that the correct results are delivered to the appropriate recipient without delay.
Quality control (QC) is defined as measures that must be included during each assay run to verify that the test is working properly.
Internal quality control (IQC) is monitoring the haematology test procedures to ensure continual evaluation of the reliability of the daily work of the laboratory with validation of tests before reports are released
Harmonization of Laboratory Indicators, 09 03-2017Ola Elgaddar
Most of Medical labs are having KPIs to monitor their performance and enhance process improvement. This presentation discusses in short the IFCC attempts to reach a consensus and harmonize medical labs quality indicators.
Quality control (QC) is a procedure or set of procedures intended to ensure that a manufactured product or performed service adheres to a defined set of quality criteria or meets the requirements of the client or customer. QC is similar to, but not identical with, quality assurance (QA).
QC IN clinical biochemistry labs and hospitals
Slides on medical laboratory testing process and pre-analytical factors that might contribute to laboratory errors and sample rejection, and how to prevent it.
In the continuous quality journey, Controlling laboratory Errors is an integral part & focusing on analytical, post-analytical process is the first step. Developing a reporting culture followed by thorough analysis and implementation of appropriate corrective, preventive actions is required.
Recently ISO 15189:2022 have become available. This would help laboratories set up processes which would yield reproducible results and improve the quality of work.
Quality control, or QC for short, is a process by which entities review the quality of all factors involved in the production. ISO 9000 defines quality control as "A part of quality management focused on fulfilling quality requirements"
This presentation gives a brief idea of Quality control and how to execute it.
Internal quality control (IQC) in coagulation labAnkit Raiyani
In the haematology laboratory it is essential to ensure that the right test is carried out on the right specimen and that the correct results are delivered to the appropriate recipient without delay.
Quality control (QC) is defined as measures that must be included during each assay run to verify that the test is working properly.
Internal quality control (IQC) is monitoring the haematology test procedures to ensure continual evaluation of the reliability of the daily work of the laboratory with validation of tests before reports are released
Harmonization of Laboratory Indicators, 09 03-2017Ola Elgaddar
Most of Medical labs are having KPIs to monitor their performance and enhance process improvement. This presentation discusses in short the IFCC attempts to reach a consensus and harmonize medical labs quality indicators.
Quality control (QC) is a procedure or set of procedures intended to ensure that a manufactured product or performed service adheres to a defined set of quality criteria or meets the requirements of the client or customer. QC is similar to, but not identical with, quality assurance (QA).
QC IN clinical biochemistry labs and hospitals
Slides on medical laboratory testing process and pre-analytical factors that might contribute to laboratory errors and sample rejection, and how to prevent it.
This content is suitable for medical technologists/technicians/lab assistants/scientists writing the SMLTSA board exam. The content is also suitable for biomedical technology students and people also interested in learning about test methodologies used in medical technology. This chapter describes test quality assurance (QA) and quality control (QC). Please note that these notes are a collection I used to study for my board exam and train others who got distinctions using these.
Disclaimer: Credit goes to those who wrote the notes and the examiners of each exam question. Please use only as a reference guide and use your prescribed textbook for the latest and most accurate notes and ranges. The material here is not referenced as it is a collection of pieces of study notes from multiple people, and thus will not be held viable for any misinterpretations. Please use at your own discretion.
Biological variation as an uncertainty componentGH Yeoh
To assist the clinical interpretation of a test result, there is a necessity to have an additional non-analytical component in the overall estimation of UM, namely the biological variation.
In manufacturing operations, production management includes responsibility for product and process design, planning and control issues involving capacity and ...
Basic QC Statistics - Improving Laboratory Performance Through Quality Contro...Randox
Randox Quality Control's latest educational guide examines Internal Quality Control, External Quality Assessment, Why laboratories should run QC, How often laboratories should run QC, Basic QC statistics and the quality control process.
For medical students, especially for early clinical exposure , it will help preclinical medical students. It gives details of about seven case reports in carbohydrate metabolism. MBBS students can use the information for theory exam also.
For medical students , it will help. Especially for preclinical students, as early clinical exposure, it will be very useful. Even for theory exam, it will help.
Extra cellular matrix is recently being explored in connection with cancer , metastases and autoimmune disorders. It is prepared for the benefit of both UG and PG medical and dental students.
Various neurotransmitters, mechanism of action and their physiological functions are explained and is useful for ug and pg students of medicine, neurology, psychiatry branches.
Porphyrias are difficult to diagnose . Here it is comprehensively explained to aid making diagnosis of porphyrias easier for the benefit of medical students and practitioners.
Renal function tests are very useful for effective clinical evaluation of renal failure for effective management. So it is useful for medical and allied professional students and clinical practitioners.
Test for pancreatic and intestinal functions are very important for clinical evaluation gastro intestinal disorders . So it will e useful for medical and allied professional students and practitioners.
Liver function tests and interpretation is a very important topic for students of medical and allied fields. It is essential for efficient practice of clinical and laboratory medicine.
Students of medical and allied subjects must be exposed to the concept of monoclonal antibodies for the efficient practice of clinical and laboratory medicine.
Concepts of acid base balance and its disorders are very important for practice of medicine.It is for the benefit of medical and students of allied fields.
Coronary heart disease due to atherosclerotic process is the major cause of death.Lipids have been implicated for enhanced atherosclerosis. The major lipids involved are triacy glycerol and cholesterol which are transported in the plasma by lipoproteins. So a better understanding of lipid transport and its abnormalities is essential for medical and health professional students.
Water and electrolyte balance is clinically very important topic . It will be very useful for both UG and PG medical students. Efforts are made to explain basic concepts clearly.
It gives basic things regarding urinalysis and will be very useful for medical students, house surgeons, laboratory technicians and postgraduates in medicine.
India Clinical Trials Market: Industry Size and Growth Trends [2030] Analyzed...Kumar Satyam
According to TechSci Research report, "India Clinical Trials Market- By Region, Competition, Forecast & Opportunities, 2030F," the India Clinical Trials Market was valued at USD 2.05 billion in 2024 and is projected to grow at a compound annual growth rate (CAGR) of 8.64% through 2030. The market is driven by a variety of factors, making India an attractive destination for pharmaceutical companies and researchers. India's vast and diverse patient population, cost-effective operational environment, and a large pool of skilled medical professionals contribute significantly to the market's growth. Additionally, increasing government support in streamlining regulations and the growing prevalence of lifestyle diseases further propel the clinical trials market.
Growing Prevalence of Lifestyle Diseases
The rising incidence of lifestyle diseases such as diabetes, cardiovascular diseases, and cancer is a major trend driving the clinical trials market in India. These conditions necessitate the development and testing of new treatment methods, creating a robust demand for clinical trials. The increasing burden of these diseases highlights the need for innovative therapies and underscores the importance of India as a key player in global clinical research.
CHAPTER 1 SEMESTER V - ROLE OF PEADIATRIC NURSE.pdfSachin Sharma
Pediatric nurses play a vital role in the health and well-being of children. Their responsibilities are wide-ranging, and their objectives can be categorized into several key areas:
1. Direct Patient Care:
Objective: Provide comprehensive and compassionate care to infants, children, and adolescents in various healthcare settings (hospitals, clinics, etc.).
This includes tasks like:
Monitoring vital signs and physical condition.
Administering medications and treatments.
Performing procedures as directed by doctors.
Assisting with daily living activities (bathing, feeding).
Providing emotional support and pain management.
2. Health Promotion and Education:
Objective: Promote healthy behaviors and educate children, families, and communities about preventive healthcare.
This includes tasks like:
Administering vaccinations.
Providing education on nutrition, hygiene, and development.
Offering breastfeeding and childbirth support.
Counseling families on safety and injury prevention.
3. Collaboration and Advocacy:
Objective: Collaborate effectively with doctors, social workers, therapists, and other healthcare professionals to ensure coordinated care for children.
Objective: Advocate for the rights and best interests of their patients, especially when children cannot speak for themselves.
This includes tasks like:
Communicating effectively with healthcare teams.
Identifying and addressing potential risks to child welfare.
Educating families about their child's condition and treatment options.
4. Professional Development and Research:
Objective: Stay up-to-date on the latest advancements in pediatric healthcare through continuing education and research.
Objective: Contribute to improving the quality of care for children by participating in research initiatives.
This includes tasks like:
Attending workshops and conferences on pediatric nursing.
Participating in clinical trials related to child health.
Implementing evidence-based practices into their daily routines.
By fulfilling these objectives, pediatric nurses play a crucial role in ensuring the optimal health and well-being of children throughout all stages of their development.
CRISPR-Cas9, a revolutionary gene-editing tool, holds immense potential to reshape medicine, agriculture, and our understanding of life. But like any powerful tool, it comes with ethical considerations.
Unveiling CRISPR: This naturally occurring bacterial defense system (crRNA & Cas9 protein) fights viruses. Scientists repurposed it for precise gene editing (correction, deletion, insertion) by targeting specific DNA sequences.
The Promise: CRISPR offers exciting possibilities:
Gene Therapy: Correcting genetic diseases like cystic fibrosis.
Agriculture: Engineering crops resistant to pests and harsh environments.
Research: Studying gene function to unlock new knowledge.
The Peril: Ethical concerns demand attention:
Off-target Effects: Unintended DNA edits can have unforeseen consequences.
Eugenics: Misusing CRISPR for designer babies raises social and ethical questions.
Equity: High costs could limit access to this potentially life-saving technology.
The Path Forward: Responsible development is crucial:
International Collaboration: Clear guidelines are needed for research and human trials.
Public Education: Open discussions ensure informed decisions about CRISPR.
Prioritize Safety and Ethics: Safety and ethical principles must be paramount.
CRISPR offers a powerful tool for a better future, but responsible development and addressing ethical concerns are essential. By prioritizing safety, fostering open dialogue, and ensuring equitable access, we can harness CRISPR's power for the benefit of all. (2998 characters)
Antibiotic Stewardship by Anushri Srivastava.pptxAnushriSrivastav
Stewardship is the act of taking good care of something.
Antimicrobial stewardship is a coordinated program that promotes the appropriate use of antimicrobials (including antibiotics), improves patient outcomes, reduces microbial resistance, and decreases the spread of infections caused by multidrug-resistant organisms.
WHO launched the Global Antimicrobial Resistance and Use Surveillance System (GLASS) in 2015 to fill knowledge gaps and inform strategies at all levels.
ACCORDING TO apic.org,
Antimicrobial stewardship is a coordinated program that promotes the appropriate use of antimicrobials (including antibiotics), improves patient outcomes, reduces microbial resistance, and decreases the spread of infections caused by multidrug-resistant organisms.
ACCORDING TO pewtrusts.org,
Antibiotic stewardship refers to efforts in doctors’ offices, hospitals, long term care facilities, and other health care settings to ensure that antibiotics are used only when necessary and appropriate
According to WHO,
Antimicrobial stewardship is a systematic approach to educate and support health care professionals to follow evidence-based guidelines for prescribing and administering antimicrobials
In 1996, John McGowan and Dale Gerding first applied the term antimicrobial stewardship, where they suggested a causal association between antimicrobial agent use and resistance. They also focused on the urgency of large-scale controlled trials of antimicrobial-use regulation employing sophisticated epidemiologic methods, molecular typing, and precise resistance mechanism analysis.
Antimicrobial Stewardship(AMS) refers to the optimal selection, dosing, and duration of antimicrobial treatment resulting in the best clinical outcome with minimal side effects to the patients and minimal impact on subsequent resistance.
According to the 2019 report, in the US, more than 2.8 million antibiotic-resistant infections occur each year, and more than 35000 people die. In addition to this, it also mentioned that 223,900 cases of Clostridoides difficile occurred in 2017, of which 12800 people died. The report did not include viruses or parasites
VISION
Being proactive
Supporting optimal animal and human health
Exploring ways to reduce overall use of antimicrobials
Using the drugs that prevent and treat disease by killing microscopic organisms in a responsible way
GOAL
to prevent the generation and spread of antimicrobial resistance (AMR). Doing so will preserve the effectiveness of these drugs in animals and humans for years to come.
being to preserve human and animal health and the effectiveness of antimicrobial medications.
to implement a multidisciplinary approach in assembling a stewardship team to include an infectious disease physician, a clinical pharmacist with infectious diseases training, infection preventionist, and a close collaboration with the staff in the clinical microbiology laboratory
to prevent antimicrobial overuse, misuse and abuse.
to minimize the developme
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How many patients does case series should have In comparison to case reports.pdfpubrica101
Pubrica’s team of researchers and writers create scientific and medical research articles, which may be important resources for authors and practitioners. Pubrica medical writers assist you in creating and revising the introduction by alerting the reader to gaps in the chosen study subject. Our professionals understand the order in which the hypothesis topic is followed by the broad subject, the issue, and the backdrop.
https://pubrica.com/academy/case-study-or-series/how-many-patients-does-case-series-should-have-in-comparison-to-case-reports/
CHAPTER 1 SEMESTER V PREVENTIVE-PEDIATRICS.pdfSachin Sharma
This content provides an overview of preventive pediatrics. It defines preventive pediatrics as preventing disease and promoting children's physical, mental, and social well-being to achieve positive health. It discusses antenatal, postnatal, and social preventive pediatrics. It also covers various child health programs like immunization, breastfeeding, ICDS, and the roles of organizations like WHO, UNICEF, and nurses in preventive pediatrics.
Navigating the Health Insurance Market_ Understanding Trends and Options.pdfEnterprise Wired
From navigating policy options to staying informed about industry trends, this comprehensive guide explores everything you need to know about the health insurance market.
One of the most developed cities of India, the city of Chennai is the capital of Tamilnadu and many people from different parts of India come here to earn their bread and butter. Being a metropolitan, the city is filled with towering building and beaches but the sad part as with almost every Indian city
R3 Stem Cells and Kidney Repair A New Horizon in Nephrology.pptxR3 Stem Cell
R3 Stem Cells and Kidney Repair: A New Horizon in Nephrology" explores groundbreaking advancements in the use of R3 stem cells for kidney disease treatment. This insightful piece delves into the potential of these cells to regenerate damaged kidney tissue, offering new hope for patients and reshaping the future of nephrology.
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1. CLINICAL LAB QUALITY
CONTROL
Dr.S. Sethupathy, M.D,Ph.D.,
Professor of Biochemistry,
Rajah Muthiah Medical College,
Annamalai University.
2. PURPOSE OF LAB TESTING
1. Single patient testing for diagnosis
2. Repeated testing in a patient for
monitoring
3. Testing a population –
Epidemiological work
3. QUALITY LAB SERVICE
Importance
• To produce reliable reports and timely reports
for diagnostic, prognostic and screening
purpose to achieve best patient care
• Cost-effective service to reduce burden on the
patient.
4. QUALITY CONTROL
• Good laboratory practice (GLP) requires Internal
Quality Control (IQC)
For Lab accreditation , QC is a must. Why?
• Quality must be designed from the front end and
not on the back end.
5.
6. TOTAL QUALITY MANAGEMENT
• It is a continuous approach to improve quality and performance
towards meeting out the demands and satisfaction of the
customers.
• It involves :
• Management
• Work force
• Suppliers
• Feed back from customers
• Plan, do, review and act- sequence of QC
7. GOAL FOR QC
• To provide cost-effective , quality lab service
for the best patient care
How to achieve?
1. By increasing the error detection, reliability
and quality is assured.
2. By reducing the false rejection of runs, it will
be cost effective.
8. GOALS OF MEASUREMENT
• Accuracy and Precision
• Accuracy is the closeness of measured value with the
true value.
• The method adopted for clinical lab has certain level of
inaccuracy.
• To minimize inaccuracy ,Quality assurance program is
run .
9. PRECISION
• It is the closeness among replicative
measurements under specified conditions.
• The wide and random dispersion of values of
the replicative measurements indicate
imprecision of the assay.
• Imprecision leads to loss of reliability and
affects serial measurements. eg- bl. glucose.
10.
11. VARIABLE
• Measurement is a varying one.
Variation can be due to
• a. Analytical variation – under control .
• b. Biological variation – Physiological
• c. Pathological variation - our concern
12. VARIABILITY OF LAB MEASUREMENTS
Due to :
• Sample collection
• Sample transport and storage
• Preparation of reagents, performance
• Maintenance of instruments
• Type of method, etc.
• Variation inherent to the biological sample.
13. To obtain reliable results
• All the sources of variation should be
minimized to differentiate pathological
variation.
• To achieve this, Minimize laboratory error.
• Perfectly estimate the components of
biological variation ( The inherent variation of
the sample)
14. CHECK POINTS OF CONTROL
• Pre-analytical
• Analytical
• Post-analytical
15.
16.
17.
18.
19.
20.
21.
22.
23. IQC AND EQA
• IQC is done on daily basis .
• It is useful for accepting or rejecting the runs based on
the variation limits.
• It is done for monitoring the quality of analysis.
• EQA is used to compare the quality between
laboratories of that area and to confirm the IQC
results.
24.
25. HOW TO ACHIEVE QUALITY RESULTS?
• Adopting approved methods
• Adopting proper calibration protocol
• Adhering to maintenance schedule
• Training the technicians
• Internal quality control
• Adopting quality assurance program
• Proper documentation and regular audits for improvement
26.
27.
28.
29.
30.
31.
32.
33.
34. INTERNAL QUALITY CONTROL
• Internal Quality Control (IQC). It includes all
SQC methods which are performed every day by
the laboratory personnel with the laboratory’s
materials and equipment.
• It checks primarily the precision (repeatability
or reproducibility) of the method.
35. EXTERNAL QUALITY ASSESSMENT (EQA)
• External Quality Control (EQC). It includes all SQC
methods which are performed periodically (i.e. every
month, every two months, twice a year) by the
laboratory personnel with the contribution of an external
center .
• It checks primarily the accuracy of the laboratory’s
analytical methods.
• Certain EQC schemes check both the accuracy and
the precision.
36. HOW MUCH VARIATION IS ALLOWED IN
MEASUREMENTS?
• Variation is unavoidable.
• It should be controlled for clinical utility.
• It is needed to reject or accept analytical runs for
reliable reports.
• Fixing up the control limits is the first step of IQC.
37. CALCULATION OF CONTROL LIMITS
• Control limits : They consist of a center value (CL) and
an upper and low control limit (UCL &LCL).
• They are created by repetitive measurements of control
samples.
• In internal SQC two or more control samples are
assayed every day and at least once per day before the
patients’ samples.
38. The steps for their calculation are the following:
1. Collects 20 – 30 successive measurements from any control
level.
2. Standard deviation (s) and mean value (μ) are calculated. The
range μ±3s is considered as “trial limits”
3. If any of the measurements exceed the range μ±3s, the outlier
is rejected. The standard deviation and mean value are calculated
once more.
4. Repeat the previous procedure until no measurement exceeds
the range μ±3s.
5. The final μ and s are the mean value and the standard
deviation of the control limits.
39. • Control limits correspond to a normal distribution.
• “μ” is considered a true value of the daily control
values .
• “s” is equal to the inherent error.
• The mean value of the daily control values is
symbolized as x bar and its standard deviation as
“SD”.
• SD = the inherent error and any other RE.
40. ERRORS AND MISTAKES
• Errors: Non-conforming results with “statistical
meaning” due to non- human action.
• Mistakes: Non-conforming results with “no statistical
meaning” due to the human errors e.g. mixing up
samples, the special samples, the control samples.
41. • Random error- It is any positive or negative
unexpected deviation from the calculated
mean.
• Systematic error- It is a change in the mean
of control values.
• It may be gradual (Trend ) or abrupt (Shift ).
They are reproducible inaccuracies and are
often due to a persistent problem .
42. •TE (total error, total
analytical error -TAE)
The sum of random error
(imprecision) and systematic
error (bias).
44. LEVEY- JENNINGS CHART
• It is used to plot control values for monitoring
• Done for successive day-to-day or run-to-run .
• A chart is prepared for each test.
• For level of control, the decision limits are first fixed.
• The limits are ± 1s, ± 2s, ± 3s from the mean.
49. QC STATISTICS
Mean
• To find out mean, the sum of the values in the data set
is divided by number of values in the data set.
Formula : ∑ Xn/n
• ∑ - sum
• Xn – Each value in the data set
• n – number of values in the data set
• Two groups having same mean can have different
spread or range.
50. VARIANCE
• Variance is the average squared deviation from the
mean:
• s2 = Σ ( xi - ẋ )2 / ( n - 1 )
• where s2 is the sample variance, ẋ is the sample mean,
xi is the ith element from the sample, and n is the
number of elements in the sample.
• The standard deviation is the square root of the
variance.
51. STANDARD DEVIATION (S)
• It is a measure of precision.
• It indicates how close the QC values are to
each other.
• Wide s indicates the imprecision and loss of
reliability.
• It is also useful for monitoring daily
performance.
52. STANDARD DEVIATION (S)
Formula
• s = √ ∑ (xi - ẋ) 2 / n-1
• s- standard deviation
• ẋ - mean
• ∑ (xi - ẋ) 2 - The sum of the squares of the
differences between individual QC values and the
mean
• n- number of the values in the data set
53. IF ANALYTICAL PROCESS IN CONTROL
• 68% of QC values are within ± 1s
• 95.5% of QC values are within ± 2s
• 99.7% of QC values are within ± 3s.
• 0.3 % of QC values are outside ± 3s and are
associated with significant error . So patient
results should not be reported.
54. STANDARD DEVIATION
• In case of serious loss of precision,
the following things are to be looked in to.
1. Change of reagent
2. Regarding maintenance schedule
3. Recent Calibration
4. Reagent , sample pipettes status
5. Any change of operator
55. COEFFICIENT OF VARIATION
• It is the ratio of standard deviation to the mean of the data
set expressed as percentage.
• CV = ( s / ẋ ) 100
• It is used
1. To compare precision of two methods.
2. To compare two different methods with
different s .
3.To compare instrument performance.
57. DECISION ABOUT OF THE CHOICE OF
THE KIT
• Since the clinical decision about pregnancy
is based on low level, only kit 1 or 2 is
useful and so the kit 3 is not selected.
• Imprecision and inaccuracy are most
important at the clinical decision levels.
58. WHAT IS AN ACCEPTABLE CV?
It is decided based on
• Precision information given in the product insert or
instrument manual
• Inter-laboratory comparison (QC) programs
• Proficiency surveys
• Evaluations of methods, instruments published in journals
• CLIA proficiency limits (USA)
59. COEFFICIENT OF VARIATION RATIO (CVR)
• It is useful for comparing the precision of the lab test with peer
lab group using the same reagent, same instrument.
• CVR = Within lab CV / peer group CV
• If ratio is less than 1, the precision is better than peer group lab.
• Ratio greater than 1.5 needs investigation for the cause of
imprecision.
• Ratio greater than 2 needs troubleshooting and corrective
action.
60. CONTROL CHART
• The control chart is a graph used to study how a process
changes over time. Data are plotted in time order.
• A control chart always has a central line for the average, an
upper line for the upper control limit and a lower line for the
lower control limit.
• Lines are determined from historical data. By comparing current
data to these lines, you can draw conclusions about whether the
process variation is consistent (in control) or is unpredictable
(out of control, affected by special causes of variation).
61.
62. WESTGARD RULES
• Dr.James Westgard’s six rules are used
individually or in combination to evaluate the
quality of analytical runs.
• The rules are expressed as NL where N stands
for number of control observations and
subscript L stands for statistical limits for
evaluating control observations.
63. WESTGARD RULES
• Rule 12s - single control observation lies outside the ± 2s
limits. It is a warning sign and the run is not rejected.
• In the absence of error, 4.5% of quality results lie between ± 2s
and ± 3s limits.
• The relationship between current, previous analytical runs
should be examined .
• If no source of error is found, it is an acceptable random error
and the patient results can be reported.
64.
65. APPLICATIONS OF RULE 22S
Within run : It affects the current analytical run. If both
level 1 and level 2 controls are greater than 2s limits
on the same side of the mean, this violates within run
for systematic error.
Across runs : If level one is -1s and level 2 is +2.5s,
then previous run is examined and if level 2 is more
than + 2s, then it violates for systematic error and the
current run is rejected.
66.
67. • Rule 13s - Any QC value outside
3s limits violates this rule for
random error and the run is
rejected. It may be the beginning
of a large systematic error.
68.
69. Rule R4s : It identifies random error within
run only .
• If there is more than 4s difference between the
controls in the same run, this rule is violated for
random error. Eg: If level 1 is +2.8s and level 2 is
– 1.4 s , the difference 4.2s . It violates the run for
random error and the run is rejected.
• For three level controls, two of three shows more
than 4s difference, the run violates for random
error and it may be the beginning of systematic
error. So it should be rectified.
70.
71. • Violation of the following rules does not require rejection of
analytical runs. These indicate smaller systematic error or
analytical bias which may not be clinically relevant. These can be
eliminated by calibration and or instrument maintenance.
• Rule 31s : Three consecutive results greater than 1s on the
same side of the mean.
• Rule 41s : Four consecutive results greater than 1s on the
same side of the mean.
• Violation of these rules - applications
• If level 1 control is used, it is systematic bias over a narrow
concentration. If three level controls are used in combination , it
violates for systematic error over a broader concentration.
72.
73. • Rule 10 ẋ : 7 ẋ, 8 ẋ, 9 ẋ, 10 ẋ, 12 ẋ
• These rules are violated when 7or 8 or 9 or 10 or
12 control results are on the same side of the
mean regardless of the s.
• Applications
• If level 1 control is used, it is systematic bias over
a narrow concentration. If three level controls are
used in combination , it indicates systematic bias
over a broader concentration.
74.
75. QC LOG
It should contain :
• Name of the test
• Name of the instrument
• Units
• Date
• Initials of the person performed
• Results of each level of control assayed
• Actions taken in case of out of control QC values
• Name of the method
• Assay temperature in case of enzymes
• Supervisor’s notes