factors influencing quality lecture 1
DESCRIPTION
Factors Influencing Quality lecture 1. Problem Scenario. You want to have an overall view of what can influence the quality of your results concerning a new PCR test on H5N1 which has been set up in your laboratory. Establish the checklist you will use. Organization. Personnel. Equipment. - PowerPoint PPT PresentationTRANSCRIPT
Factors InfluencingQuality lecture 1
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Problem Scenario
You want to have an overall view of what can influence the quality of your results concerning a new PCR test on H5N1 which has been set up in your laboratory. Establish the checklist you will use.
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The Quality System
Process Control
(Quality Control & Specimen
Management)
Purchasing & Inventory
AssessmentOccurrence
Management
Information Management
Process Improvement
Customer Service
Facilities & Safety
Organization Personnel Equipment
Documents & Records
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Learning Objectives
At the end of this activity, you will be able to: Understand the main factors influencing quality
of analysis results Understand the importance of ALL the different
factors in the production of reliable results
1. Examples of factors influencing quality
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An Example: HIV
Factors influencing quality: Bad/inadequate sample identification Contamination (cross-sample contamination, distillated
water quality, contaminated micropipettes, reuse of ELISA plates)
Bad incubation of ELISA plates (if needed) Bad equipment (bad wavelength, etc.) Bad reagents (expired, bad conservation temperature, low
sensibility, inadequacy, etc.) No or bad quality control (internal/external)
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An Example: HIV (continued)
Factors influencing quality: Destruction of the plate’s coating with the micropipette Misuse of the micropipette (bad tips, bad calibration) Irregularity of the measurements due to the lack of written
techniques Result transcription mistakes Result back mistakes (telephone especially) False positive, false negative
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Another Example
Data from JAMA, 1996 Survey done in the USA Frequency of laboratory mistakes: 1 %o
7 % in the analytical step 93 % in pre/post analytical steps
45 % of the mistakes are important, with consequences for diagnosis and/or treatment of the disease
Most common mistakes = copying/recopying mistakes
2. The common mistakes
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How is quality affected?
The common mistakes: Analysis prescription Sampling conditions Specimen transport and conservation Training level of technical staff Reagents and equipment quality Insufficiency of control procedures Analytical process Interpretation of raw results Transcription and diffusion of the results Interpretation and use of the results
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Analysis Prescription Bad prescription
Too much: toxoplasmosis IgM for prenatal checking Not enough: IgG only during acute phase of a disease,
pathogen micro-organism without AST, Pneumococcus without penicillin MIC…
Inadequate: normal urine analysis for urethritis, bacteriological analysis after treatment initiation
Incomplete prescription Suspicion of typhoid fever, stool culture without blood
culture or vice versa No verification of the efficiency of some treatments (stool
parasites) Anarchical self-prescription (low)
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Sampling Conditions Bad identification of the specimen, incomplete or
unreadable identification Inadequate sampling material (contaminated, containing
disinfectants, multiple use, bad anticoagulant) Inadequate timing of samples:
Sampling after ATB treatment begins Cyclic sampling (filariosis, cortisol) not respected Sampling outside fever acme (malaria, septicemia) or if
hypothermia or if acute phase of the disease (typhoid fever: blood culture before W4)
Long tourniquet time for coagulation tests Inadequate sample: first drop of urine for standard urine
analysis (considered as urethral sample)
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Specimen Transport & Conservation
Inadequate conservation delay Inadequate transportation and conservation temperature Blood sample badly prepared (slow centrifugation, RBC not
separated, frozen without separating RBC) None or inappropriate transport media (Cary-Blair media for
meningitis) Packaging conditions (biosafety regulations, compatibility
with further analysis, addressee contact information) Addressee absent or not reachable No follow-up of the specimen by the sender
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Training Level of Technical Staff Insufficient training level:
Sampling Biosafety Technical Analysis management (logbooks, data, reports, conclusions)
Large inter-technician variability (between technicians) Large intra-technician variability (in one technician) Lack of continuous training and refreshing Techniques not standardized, not unified in the country
large variability between laboratories Lack of training for support staff (cleaners, janitors, reagents
preparation, etc.) Inadequation between initial training and current
responsibilities
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Reagents and Equipment Quality
Usually “least expensive” often “worst quality” No/little preventive maintenance No/little meticulous follow-up of the cold chain and how
equipment are functioning No duplication of critical equipment, no possibility to refer
the specimen if there are analysis problems No expiration logbook, use of expired or badly conserved
reagents No check of spectrophotometers and ELISA readers
(parasitic light, absorbance, band-width, linearity, etc.) No periodical calibration of the equipment
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Analytical Process
Lack of written technique or containing lots of deletions and changes
Old or imprecise technique (Stokes techniques for AST, Kovacs on urine, AST on pure urine, etc.)
Analysis of the inadequate part of the specimen (sputum for TB, bloody diarrhoea)
Serum pooling! Petri dishes split in two (or even in four), reuse of micropipette tips
Insufficient time devoted to the analysis (20 minutes minimum for malaria and TB)
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Insufficiency of Control Procedures No quality assurance system No quality supervisor in the laboratory No national list of registered reagents (or no official
use of the list of another country) No control of culture media, no logbook for the
preparation of media and reagents No positive and negative control for serologies and
other analyses No standardisation of inoculums for AST No participation in any EQC programme
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Interpretation of Raw Results Total dissociation of the units (chemistry, haematology,
bacteriology) problem for global validation No interpretation of bacterial resistances (no expert system) Special physiological situations not integrated:
Children/Pregnant women/The elderly Special pathological situations not integrated:
Renal/liver insufficiency Dehydration/High temperature
No access to patient history Lack of critical thinking concerning results Too much confidence in the automated analyzer
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Transcription and Diffusion of Results
Reminder: the signing biologist might also be in charge of results transmission
Results transcription mistakes; most common mistake in a laboratory
“Rapid” validation/signature unable to avoid incoherence
Delays in result transmission Insufficient, incomplete or delayed weekly report to
surveillance services
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Interpretation and Use of Results
No conclusion or comments on the analysis report Bad interpretation by the prescriber/clinician Prescribers lack confidence in laboratory results
(Communication? Quality assurance? Other?) No access to patient history Incorrect use of the data by surveillance services:
Data integration Denominator problems
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Controllable factors or not? 2 different types of factors:
Controllable by the laboratory (usually analytical factors)
Non controllable by the laboratory (pre and post analytical factors in general)
Final goal: Decrease factors controllable by the lab Communicate with pre and post analytical actors
in order to help them control these factors
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Don’t forget
Stock managt
IQC, EQCQAM
Equipment & maintenance
Analysis and reports
management
Analysis
PrescriptionInterpretation
Cold chain
Training level of the staff
Reagents and consumables
Organization
Sampling
Summary
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Summary
Each of the twelve Quality System essentials can be influenced by many factors
This Set of coordinated activities must function as building blocks for quality management.
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Problem Scenario
You want to have an overall view of what can influence the quality of your results concerning a new PCR test on H5N1 which has been set up in your laboratory. Establish the checklist you will use.