Quality Management in Medical Laboratory
Internal Quality ControlDr. Adel A. ElazabAssociate Professor of Clinical PathologyFaculty of MedicineAin Shams University, Cairo, Egypt
Quality Concept
All management systems are focused on getting the job done.
Some have been effective in making larger profits while others have been effective in providing a better service.
More efficient and effective management guarantees the job to be done in the proper way.
Stages of QualityNCCLS Approved Guideline - GP26A
STAGE ACTIVITIES PERFORMED1. TOTAL QUALITY MANAGEMENT Management approach centered around
“Customer Satisfaction”2. QUALITY MANAGEMENT All of the below plus the economic
aspects of “Cost of Quality”3. QUALITY SYSTEM “Comprehensive and Coordinated”
efforts to meet quality objectives4. QUALITY ASSURANCE Systematic activities to provide
“Confidence” that the organizationmeets requirements for quality
5. QUALITY CONTROL Operational techniques applied to“Specific Tasks” for quality andregulatory compliance.
Stages of Quality
Quality : degree to which a set of inherent characteristics fulfills requirements
Quality control: part of quality management focused on fulfilling quality requirements
Quality assurance: part of quality management focused on providing confidence that quality requirements will be fulfilled
Quality management: coordinated activities to direct and control an organization with regard to quality
The March of Quality Management
1942-52 US Military develop requirements for contractors for shell, aircraft, missile suppliers (Quality without 100% inspection)
1947 International Organization for Standardization (ISO) created to adopt industrial standards
1959 US Department of Defense established MIL-Q-9858 quality management
1963 MIL-Q-9858 is internationalized as an ABCA standard
1968 NATO adopts MIL-Q-9858A as Allied Quality Assurance Publication 1 (AQAP-1)
1979 British Standards Institute (BSI) developed AQAP-1 for civilian use BS 5750
Quality Management System
A laboratory QMS is a systematic approach that describes, documents, implements, measures, and monitors the effectiveness of laboratory work operations in meeting international, national, regional, local, and organizational requirements and promotes the efficient use of resources.
Outcomes of QMS:-
Quality System Essentials The goal of an efficient and effective laboratory is
to provide consistently accurate results in a timely manner with the most judicious use of resources.
Quality system essential: an essential building block of a quality management system that addresses, at a minimum, regulatory and accreditation requirements within a specific topic needed to fulfill those requirements and stated quality objectives.
The 12 quality system essentials (QSEs) are universal and applicable to any size laboratory, whether simple or complex, in any laboratory discipline.
Calibration: the process of testing and adjustment of an instrument, kit, or test system to provide a known relationship between the measurement response and the value of the substance measured by the test procedure
Effectiveness: the extent to which planned activities are realized and planned results achieved
Efficiency: the relationship between the results achieved and the resources used
Non-QMS processes – processes that are not contained in either the QSEs or in the laboratory’s path of workflow, such as those within the finance, sales, or marketing functions.
Path of workflow: the sequential processes in a laboratory’s activities that transform a request for examination into the laboratory information that is captured in the report of results.
Plan: written account of intended future course of action aimed at achieving specific goal(s) or objective(s) within a specific timeframe and explains in detail what needs to be done, when, how, and by whom.
OrganizationCustomer FocusFacilities and SafetyPersonnelPurchasing and InventoryEquipmentProcess Management
Pre-examinationExaminationPost-examination
Documents and RecordsInformation ManagementNonconforming Event ManagementAssessmentsContinual Improvement
Pree-xaminationExaminationPost-examinationInformation
Management
Quality System Essentials - those elements which must be applied to all operations in the service’s path of workflow
Path of Workflow - as it relates to the processes involved in the pre-, during and post- phases of delivery of services with the laboratory as an example
Laboratory Path of Workflow
Quality SystemEssentials
OrganizationPersonnelEquipmentPurchasing/ InventoryProcess ControlDocuments/ RecordsOccurrence ManagementInternal AssessmentProcess ImprovementService and Satisfaction
Post Information Preanalytical Analytical Analytical Management
Quality system essentialsapply to all operations
in the path of workflow
Patient Test Specimen Specimen Specimen Testing Laboratory Results Post-test Laboratory Interpretation/Assessment Request Collection Transport Receipt Review InterpretationReport Specimen Information Consultation
Management Testing System
The Quality Toolbox
The Quality Toolbox
Lean
RISKFMEA
Six Sigma
Metrics
Surveys
Statistics
The Quality Toolbox
Mega-Tools◦ Lean◦ Six Sigma ◦ Priority Matrices and
Risk Assessment
Tools/Techniques◦ Balanced Scorecards◦ Brainstorming◦ Control Charting◦ Flow Charting◦ Quality Indicators◦ Surveys
Tools in the Toolbox
QUALITY ASSURANCEPROGRAMME
! Internal Quality Control (IQC) Procedures
! External Quality Assessment (EQA)
! Quality Management
Internal Quality Control (IQC)Procedures
⇒ Done during daily routine work⇒ Provides an immediate control⇒ Errors are corrected immediately⇒ Routinely collect and analyze data
from every test run or procedure
Why do we need Internal Quality Control?
! Ensure that test results are reliable! Ensure that test results are
reproducible! Control quality of daily routine work
Internal Quality Control
Monitoring quality of laboratory testing, accuracy and precision of laboratory
results
Precision and Accuracy Precise and Inaccurate Precise and Accurate
Precision and Accuracy Imprecise and Inaccurate Imprecise and ??
Accurate
Internal Quality Control It ensures continual check that the established
reliability of the laboratory’s work does not fluctuate and that reports are validated before they are released.
It is based on monitoring the procedures which are actually used for the tests in the laboratory. It includes:
· Control charts with tests on control materials· Duplicate tests on all specimens or on a proportion
of the specimens· Delta check, comparing current test results with
previous results· Consistency of mean values of patient data
Analytical run: is an interval within which the accuracy and precision of the measuring system is expected to be stable; between which events may occur causing the measurement process to be more susceptible (i.e., greater risk) to errors that are important to detect.
Each lab should define the run length because the operating conditions, workload, and application of the measurement procedure in the laboratory may differ from nominal conditions evaluated by the manufacturer.
Based on:◦ The expected stability of the measurement
procedure◦ The number of patient samples typically being
analyzed◦ Cost of reanalysis in the event of a QC failure,◦ Workflow patterns◦ Operator characteristics◦ The clinical impact of an undetected error condition
existing for a period of time before the next QC measurement(s)
◦ Stability of an analyte in patient samples
QC Quantitative Tests
Use 2-3 levels of controls covering the medical decision points
At least 20 control values over a period of 20-30 days for each level of control
Perform statistical analysis Develop Levey-Jenning chart Run -regularly- with patient samples Monitor control values on chart using
Westgard rules Take immediate corrective action, if
needed Record actions taken (if any)
QC Quantitative Tests QC material must be available in large
quantities stored in small aliquots (Ideally should last for at least 1 year)
Always consider as Biohazardous Requires very accurate reconstitution if
needed Always deal with and store as
recommended by manufacturer
Analysis of Control Materials
Need data set of at least 20 points obtained over 20-30 days better by different operators in different times of day
Calculate mean, standard deviation, Coefficient of variation and determine target ranges
Develop Levey-Jenning charts Plot –on the chart- control values each
run/ day Make decisions regarding acceptability
of run using Westgard rules Monitor over time and at defined
intervals
1. 192 mg/dL2. 194 mg/dL3. 196 mg/dL4. 196 mg/dL5. 160 mg/dL6. 196 mg/dL
7. 200 mg/dL8. 200 mg/dL9. 202 mg/dL10. 255 mg/dL11. 204 mg/dL12. 208 mg/dL13. 212 mg/dL
Calculation of the Mean: Outliers
Levey-Jennings Chart Calculate the Mean and Standard Deviation;Record the Mean and +/- 1,2 and 3 SD Control Limits
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
Day
Mean
+1SD
+2SD
+3SD
-1SD
-2SD
-3SD
Levey-Jennings Chart -Record and Evaluate the Control Values
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
Day
Mean
+1SD
+2SD
+3SD
-1SD
-2SD
-3SD
Findings Over Time
Ideally should have control values clustered around the mean (+/-2 SD) with little variation in the upward or downward direction
Imprecision = large amount of scatter around 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
ERRORS
Random Error (RE): Imprecision
Causes:1. Pipetting error2. Temperature error3. Mixing defect4. Machine need
troubleshooting
Systematic Error (SE): Inaccuracy
Causes:1. Deterioration of
control material2. Deterioration of
calibrator3. Deterioration of
reagents
Westgard Rules Allows determination of whether an
analytical run/s (in control) or (out of control)
October 1, 2008
October 1, 2008
Westgard Multirules
When you're running 2 or 4 control levels, use the rules: 13s/22s/R4s/41s/10x
When you're running 3 control levels, use a set that works for multiples of threes:13s/2of32s/R4s/ 31s/12x
When a Rule is Violated
Rejection rule = Out of control=1. Stop testing2. Identify and correct problem3. Repeat testing on pt samples and
control4. Don’t report pt results until problem
is solved and controls indicate proper performance
When a Rule is Violated
Change one variable at a time to troubleshoot an out of control test.
The variables are usually common to all instruments or procedure systems and include the following:
1. Try a fresh vial of QC 2. Try a new reagent (same lot) 3. Try a new consumable (water, part, solution, tubing)
if applicable. 4. Try a new reagent (new lot) 5. Recalibrate (current calibrator) 6. Recalibrate (new lot calibrator) If a system cannot be brought into control,
notify senior staff. Do not process patient samples for the test affected.
Overlap New Lot of Controls
When changing to a new lot number of control material, ideally there should be an overlap period while the new material is being analyzed to establish the new control limits.
In cases where the overlap period is not sufficient, it is possible to establish the mean value for the new control material in a short time, over say a five-day period, or to start with the manufacturer’s values.
Then apply the previous estimate of SD to establish the control limits.
These control limits should be temporary, until sufficient data is collected to provide good estimates of both the mean and SD of the new material.
Establishing the Value of the Mean for a New Lot of QC Material
New lots of a quality control material should be analyzed for each analyte in parallel with the lot of control material in current use.
Ideally, a minimum of at least 20 measurements should be made on separate days when the measurement system is known to be stable, based on QC results from existing lots.
If the desired 20 data points from 20 days are not available, provisional values may have to be established from data collected over fewer than 20 days.
Possible approaches include making no more than four control measurements per day for five different days
Retained patients samples◦ Original samples must be assayed in the lab under accepted
control run conditions◦ Stored aliquited immediately after finishing 1st analysis◦ Storage conditions must meet the requirements for analytes to
be measured◦ Avoid repeated warming/ thawing◦ Stability of the measurand must be carefully respected◦ Better to be alternating with QC material◦ Result of the 1st assay is used as the base for comparison and
calculation (as if gold value)◦ Allowable analytical imprecision is used for judgment of
acceptance or rejection◦ Data calculated from biological variations/ CLIA limits are used
for the issue
When QC Material is deficient:
When QC Material is deficient: (cont.) Result comparison with an in-control
method/ instrument/ procedure for the measurand◦ The in-control instrument/ method is considered
the reference one◦ Not more than one hour time gap between the
parallel assays◦ Principles of assays must be considered if
different◦ Inaccuracy limits is used for comparison◦ Data calculated from biological variations/ CLIA
limits are used for the issue
Individual Patient Results:◦Clinical Correlations◦Correlation with other laboratory tests◦Intralaboratory duplicates◦Delta check with previous test results◦Limit Check
Multiple Patients:◦Test distribution statistics◦Monitoring patients means
Quality Control Using Patient Data
YOUR VALUABLE QUESTIONS
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