WEQAS: what is it and what does it mean?. Celia Critchley Point of Care Co-ordinator Warrington and Halton Hospitals NHS Foundation Trust

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1 WEQAS: what is it and what does it mean?. Celia Critchley Point of Care Co-ordinator Warrington and Halton Hospitals NHS Foundation Trust

2 Objectives Overview of External Quality Assessment and its relevance to health care professionals and their patients Relationship between EQA and Quality Standards in Healthcare Introduction to WEQAS Purpose of EQA

3 Objectives The Abbott I-Stat and Blood Gas EQA The WEQAS report what does it mean and what to look out for Examples Identifying problems and what to do about them

4 External Quality Assessment EQA is defined as a system for objectively checking a laboratory s performance using an external agency or facility. Proficiency testing an external provider sends unknown samples for testing to a set of laboratories, and the results of all laboratories are analyzed, compared, and reported to the laboratories.

5 EQA helps to assure customers, such as physicians, patients, and health authorities, that the laboratory can produce reliable results. Care Quality Commission NHSLA Clinical Pathology Accreditation (CPA) UK

6 WEQAS Wales External Quality Assessment Scheme WEQAS Quality Laboratory part of the Cardiff and Vale University Health Board Supplies Blood Gas and Co-oximetry samples for Laboratory based and Point of Care Testing instruments

7 Purpose of EQA An evaluation of a participant s measuring performance compared with other laboratories using the same methods. Schemes can be used to assess one or more of the following: The quality of the analytical performance of the participant s laboratory Intralaboratory variation Interlaboratory variation Relationship between calibration procedures and analytical results Relationship between analytical procedures and results Relationship between commercial reagents and results Relationship between analytical instruments and results Systematic deviations for the individual laboratory from state-of-theart values or reference target values

8 The Abbott I-Stat and Blood Gas EQA Currently around 160 I-Stat instruments registered with WEQAS for Blood Gas Scheme Monthly distribution of 3 samples per instrument 2.5 ml sealed glass ampoules. Tonometered protein based aqueous material is used. Additional freshly tonometered bovine blood sample distributed annually

9 The WEQAS Report - Analyte Specific

10 The WEQAS Report Analyte Specific

11 The standard deviation shows how much a value varies from the average or expected value (mean). A low standard deviation indicates the data points are very close to the mean; a high standard deviation indicates that the data points are spread out over a large range of values. Your report will show your reported result, your method mean and the overall mean. WEQAS will calculate your results standard deviation from the method mean (for ph (H+), pco2 and po2) and from this a standard deviation index (SDI) score is calculated. The average SDI score is then calculated for each analyte.

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13 Also shown on the report is a graph of the previous distributions analyte SDI score allowing an overview of any adverse trends

14 The WEQAS Report

15 The WEQAS Report Other information included on the WEQAS report: Bias plot (Bland Altman) for samples from the current distribution and also from this and previous distributions Precision and accuracy indicators

16 So What should I be looking for?? Blood gas and ph on the I-Stat: Compare your results with method mean (I-Stat) SDI for each sample analyte ideally <1; <2 is acceptable Review SDI graphs for previous distributions to identify any adverse trends Managers performance summary gives an easy-to-read indication of problems

17 Managers Performance Summary Sheet

18 Managers Performance Summary Sheet

19 Poor Performance Procedures Flag up as poor performer after 2 consecutive SDIs >2 on an individual analyte Contact from scheme organiser to notify participant of poor performance and to offer assistance A response must be made and action taken within 3 months or a second letter is sent to the participant No response to second letter from WEQAS identifies the participant as a persistent poor performer and the appropriate National Quality Assessment Advisory Panel (NQAAP) will be notified.

20 Help! I m a poor performer! Common causes of poor performance on I-Stat EQA Incorrect WEQAS sample preparation by operator Sample or cartridge temperature Incorrect storage conditions for cartridges Incorrect sampling technique Transcription errors Non-return of results!

21 What can I do? Ensure you are using the correct techniques for EQA analysis as per WEQAS instructions Run IQC samples to check cartridge performance Check cartridge storage temperatures / expiry dates Request repeat samples from WEQAS Log any deviations from the procedure (e.g. delay in analysis etc) at the time of running the EQA

22 Where can I get advice? Abbott Customer Helpline WEQAS telephone enquiries WEQAS.com Your local laboratory (may have POCT service)

23 Any Questions?