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:
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 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 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
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 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 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
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 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 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 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 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 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 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 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 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 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 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 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 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 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 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.