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Factors Influencing Quality lecture 1. 2 Problem Scenario  You want to have an overall view of what can influence the quality of your results concerning.

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Presentation on theme: "Factors Influencing Quality lecture 1. 2 Problem Scenario  You want to have an overall view of what can influence the quality of your results concerning."— Presentation transcript:

1 Factors Influencing Quality lecture 1

2 2 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.

3 3 The Quality System Process Control (Quality Control & Specimen Management) Purchasing & Inventory Assessment Occurrence Management Information Management Process Improvement Customer Service Facilities & Safety Organization Personnel Equipment Documents & Records

4 4 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

5 1. Examples of factors influencing quality

6 6 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)

7 7 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

8 8 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

9 2. The common mistakes

10 10 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

11 11 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)

12 12 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)

13 13 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

14 14 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

15 15 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

16 16 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)

17 17 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

18 18 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

19 19 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

20 20 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

21 21 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

22 22 Don’t forget Stock managt IQC, EQC QAM Equipment & maintenance Analysis and reports management Analysis Prescription Interpretation Cold chain Training level of the staff Reagents and consumables Organization Sampling Summary

23 23 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.

24 24 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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