Quality Control and Quality Assurance for Antibiotic Testing

Size: px

Start display at page:

Download "Quality Control and Quality Assurance for Antibiotic Testing"

Hillary Ellis
6 years ago
Views:

1 Quality assurance Quality Control and Quality Assurance for Antibiotic Testing 26 Sep 2013 Microbiology Technical Workshop Lily Ng Siew Yong practice of assessing performance in all steps of the process to promote excellent outcome in medical care Quality control aggregate of processes and techniques to detect, reduce, and correct deficiencies in an analytical process. Processes Quality Assurance With thanks to Derek EUCAST Educational Workshop: 31 March 2012

2 Standard documentation External quality assurance Routine Quality Control External Quality Assurance The challenge of laboratory procedures with specimens of known but undisclosed content Evaluation Quality Internal Quality Assurance External laboratory Or organization Prepares sample and sends to participants Receives and analyses results Participating laboratory Receives sample and performs testing Reports results Prepares report Analyses reports & deficiencies Validation Education & Training Institutes corrective actions EQA Examples of EQA organizations College of American Pathologists Royal College of Pathologists (Australasia) UKNEQAS Local reference laboratories EQA: benefits Independent assessment of performance Assessment of performance over time Comparison with other laboratories Highlights problem areas Performance related to guidelines and methods

3 EQA: benefits International differences highlighted EQA: limitations Number of specimens distributed is small Gives practical experience of difficult tests (especially if resistance is uncommon) May be considered inappropriate to send some organisms Provides background information and guidance on appropriate methods Performance indicator for accreditation Specimens do not reflect routine isolates Laboratories may not treat specimens as routine CGH Laboratory Survey subscription based on services offered Survey sample management Internal Quality Assurance The challenge of laboratory procedures by repeat testing of specimens of unknown content Sample Result submission management Performance assessment routine testing results blinded routine testing results reported compare & evaluate

4 Internal Quality Assurance The challenge of laboratory procedures by repeat testing of specimens of unknown content Internal Quality Assurance The challenge of laboratory procedures with spiked specimens Sample Sample Spiked sample blinded blinded Routine testing routine testing routine testing routine testing routine testing results results results results results reported reported compare & evaluate reported compare & evaluate Compare & evaluate IQA: Benefits Check of laboratory processes Identifies: typographical errors Inconsistencies between different technologists process errors IQA: Practical issues Different organisms picked from mixture on primary plates Borderline susceptibility leads to variation Discrepancies with difficult tests Labor intensive Sample variability (stored samples)

IQA: @ CGH Laboratory Target: 50 specimens issued monthly Frequent issues: Variation in zone diameters Enumeration of cells Urine viable count Audit Processes Documentation Skills Knowledge check

5 CGH Laboratory Target: 50 specimens issued monthly Frequent issues: Variation in zone diameters Enumeration of cells Urine viable count Audit Processes Documentation Skills Knowledge check -inspect -verify CGH Laboratory Accreditation audit Internal surveillance Target 10 % of total test specimens July 2013: 1,198 of 13,209 specimens CGH Laboratory Errors Internal surveillance 10 % of total test specimens July statistics: 1,198 of 13,209 specimens Frequent issues: Variation in zone diameters Enumeration of cells Urine viable count

Documentation Documentation Standard operating procedures user-friendly, not reference text! Examples from: WHO SOP (SE Asia) http://apps.searo.who.int/pds_docs/b0217.

pd f updated regularly document control Readily accessible HPA (UK) SOP repository http://www.hpa.org.uk/smi Mount Sinai SOP http://microbiology.mtsinai.on.ca/manual/anti/ind ex.

6 Documentation Documentation Standard operating procedures user-friendly, not reference text! Examples from: WHO SOP (SE Asia) Standard operating procedures user-friendly, not reference text! Examples from: f updated regularly document control Readily accessible HPA (UK) SOP repository Mount Sinai SOP ex.shtml updated regularly document control Readily accessible Documentation Standard operating procedures user-friendly, not reference text! updated regularly document control Evaluation & Validation For new testing methods / antibiotics introduced into laboratory Analytic accuracy Compare new against gold standard Readily accessible hard copy soft copy Precision Repeatibility

Evaluation & Validation @ CGH Laboratory www.hpa.org.

7 Evaluation & CGH Laboratory paweb_c/ Introducing use of yeast AST testing by Vitek Analytic accuracy Precision Compare results obtained by Vitek against reference microbroth dilution method using a range of various species 20 consecutivedays of parallel testing Education & Training Competency Define skills to be assessed Define how to assess Define who will assess Documentation Remediation Continuing professional education Skills upgrading Reference Competency Assessment in the Clinical Microbiology Laboratory. Clin. Microbiol. Rev. July 2004 vol. 17 no. 3, Importance of proper technique for AST Observation of resistance mechanisms expression in Proteuses Antimicrobials and the beta lactam family drug family Extended spectrum beta lactamases Staph lugdunensis: significance, identification, and susceptibility ampc beta lactamases Penicillin binding proteins in relation to staphylococcal growth and drug resistance Antimicrobial testing and reading of test findings Training topics Lab reports vs clinical impact of Staphylococcal AST Interpretation and reporting of test results for Enterococcal AST Interpretation and reporting of test results for EnterobacteriaceaeAST Interpretation and reporting of test results for non-enterobacteriaceae ASTcs Identification, susceptibility testing and result interpretation of Strep pneumoniae MIC determination by macrobroth and microbroth methods Microscan testing Drug options, result interpretation and reporting for Staphylococcal AST

Education & Training @ CGH Laboratory Microbiology Training Record Training Date Topic Trainer Hr LNG GHT ELC HYX HJ SMF LHZ TSY SFM NAP OJL Category 12/03/2013 Talk Importance of proper technique

8 Education & CGH Laboratory Microbiology Training Record Training Date Topic Trainer Hr LNG GHT ELC HYX HJ SMF LHZ TSY SFM NAP OJL Category 12/03/2013 Talk Importance of proper technique for AST LNG 0.5 Trainer p p AL p p p OFF p p 26/03/2013 Practical Observation of resistance machanisms expression in Proteuses 11/04/2013 Powerpoint Antimicrobials and the beta lactam family drug family LNG 1 Trainer p p p p p p p p p HJ / LNG 0.5 Trainer P P P Trainer P P P P P 17/04/2013 Powerpoint Extended spectrum beta lactamases HJ / LNG 1 Trainer P AL P Trainer P P P P 22/04/2013 Talk Staph lugdunensis: significance, identification, and susceptibility LNG 1 Trainer P P P P P P P P P 24/04/2013 Powerpoint ampc beta lactamases HJ / LNG 1 Trainer P P P Trainer P P P OFF P 29/05/2013 Talk Penicillin binding proteins in relation to staphylococcal growth and drug resistance Antimicrobial testing and reading of test Insert page of CME AST listing here 30/05/2013 Powerpoint 11/06/2013 Talk, part 1 11/06/2013 Talk, part 2 findings Drug options, result interpretation and reporting for Staphylococcal AST (incl FOX vs OX, E vs CC, Quinolones) Lab reports vs clinical impact of Staphylococcal AST (incl TGC, RA5, FU, Gm, SXT) LNG 0.5 Trainer P P AL P P P P P P HJ / LNG 0.5 Trainer P P AL Trainer P P P P P LNG 0.5 Speaker P P P P P P P AL P LNG 0.5 Speaker P P P P P P P AL P Quality Control Antibiotic testing QC: Antibiotic testing Temperature Media Disc potency Atmosphere Organism Specified routine quality control strains are used to monitor test performance Quality control strains must be from a reliable source Proper storage to maintain characteristics

9 QC Strains: specific tests QC Disc: acceptable ranges Acceptable range for ATCC strains QC Disc: acceptable ranges QC Disc: testing

Westgard rules Westgard relevant multiple rules used to monitor a

10x reject when 10 consecutive control measurements fall on one side of

QC Disc: monitoring QC Disc: failures ID cause Cause found: repeat x 01

10 Westgard rules Westgard relevant multiple rules used to monitor a charted process determines if the process is within acceptable limits 10x reject when 10 consecutive control measurements fall on one side of the mean. QC Disc: monitoring QC Disc: failures ID cause Cause found: repeat x 01 No obvious cause Repeat out of range Repeat ok = case close 5 consecutive days repeat All within range = case close Re-examine 1 out of range

11 Antibiotic testing: Common sources of error Media ph Thickness Wrong media QC strains Wrong strains Inocula Age Antibiotic testing: Common sources of error Media Thickness ph Wrong media QC strains Wrong strains Inocula Age Antibiotics Wrong disc Procedures Incubation conditions Disc placement transcription Antibiotics Wrong disc Procedures Incubation conditions Disc placement transcription Antibiotic testing: Common sources of error Media Thickness ph Wrong media QC strains Age Inocula Wrong strains Antibiotic testing: Common sources of error Media Thickness ph Wrong media QC strains Wrong strains Inocula Age Antibiotics Wrong disc Procedures Incubation conditions Disc placement transcription Antibiotics Wrong disc Procedures Disc placement Incubation condition transcription

Restricted range of test concentrations means that the available range may not

12 QC Disc: Troubleshooting QC of Automated Systems Use the recommended quality control strains Follow manufacturer s instructions Purity check of used inocula Restricted range of test concentrations means that the available range may not include the MIC of the control strain. Quality Assurance Some concluding thoughts

13 Quality measure Effort (%) Clinically relevant testing strategies 15 Testing of reference QC strains 15 Technical competency 15 Organism antibiogram verification 15 Supervisor review of results 15 Procedure manual 10 Cumulative antibiogram 5 Proficiency surveys 5 Other 5 Conclusion Rankin I. D. (2005). Quality Assurance/Quality Control (QA/QC) In: Coyle M. B. (ed.) Manual of Antimicrobial Susceptibility Testing. 1st ed, Washington, D.C.: American Society for Microbiology; % of Microbiology reports are wrong! Journal of Hospital Infection. Vol 30, Supp, June 1995, Pages Can we afford quality assurance in microbiology laboratories? Can we afford NOT TO HAVE quality assurance in microbiology laboratories?

14 Resources WHO Laboratory Quality Management System Handbook CLSI M40 susceptibility testing EUCAST quality tables General Review

QUALITY CONTROL FOR AST: IQCP? Romney Humphries UCLA

QUALITY CONTROL FOR AST: IQCP? Romney Humphries UCLA WHAT IS QUALITY CONTROL? Procedures used to detect errors that occur due to: test system failure adverse environmental conditions variance in operator