UK NEQAS FOR BLOOD COAGULATION: Programmi EQAS nel laboratorio di coagulazione

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1 UK NEQAS FOR BLOOD COAGULATION: Programmi EQAS nel laboratorio di coagulazione Tim Woods, Manager UK NEQAS for Blood Coagulation STH Royal Hallamshire Hospital Sheffield U.K.

2 Quality Assurance IQC Are my results the same today as they were yesterday? EQA Are my results the same as other labs doing the same test?

3 Why EQA? UK NEQAS (BLOOD COAGULATION) 2007

4 A laboratory in Philadelphia used an incorrect calculation to determine INRs 932 patients in an 8 week period given the wrong INR

5 The report indicated that the laboratory used a sensitive chemical believing it to be insensitive An ISI of 1.0 instead of 1.8 was used in the computer algorithm for INR calculation At least 2, possibly 5 patients died as a result of overdosing

6 Commercial control plasmas Very wide quoted control ranges Roche CoaguChek INR control plasma INR Biopool Haemostasis Reference plasma APTT IL normal plasma FVIII:C %

7 EQA for Blood Coagulation Tests Stable, consistent samples that, where possible, resemble clinical specimens Reliable, valid target values Adequate, topical data, from sufficient returns for statistical analysis number of participants in data returns prompt return of results from participants number of analytes in each distribution frequency of distributions

8 EQA for Blood Coagulation Tests: 2 Effective communication of performance data through: well-composed, informative and easily understood reports sequential historical performance grades Quality assessment of haemostatic assays and external quality assessment schemes Laboratory Techniques in Thrombosis: A Manual; Kluwer Academic Publishers

9 UK National External Quality Assessment Service (UK NEQAS) NHS organisation, Blood Coagulation (and others) based in Sheffield Not-for for-profit organisation, funded directly by participation fees Participants in over 80 different countries (BC; 30 countries) In UK, overseen by Steering Committee, NQAAP, JWG, DoH. Remit to improve laboratory performance

10 UK NEQAS : Objectives To provide laboratories with an assessment of performance both within the laboratory and in relation to that of other laboratories. To provide information on the relative performance of available kits and methods. To identify factors associated with good and poor performance. To monitor and improve the between-laboratory agreement. The primary role of UK NEQAS is education!

11 UK NEQAS Haematology Division Royal Hallamshire Hospital, Sheffield Blood Coagulation Leucocyte Immunophenotyping Watford General Hospital General Haematology Blood Transfusion Laboratory Practice Good Hope Hospital, Sutton Coldfield Haematinics

12 UK NEQAS for Blood Coagulation: Surveys Participation available in the following programmes: Blood Coagulation: Level 1 Level 2 Point of Care / Near Patient Testing (POCT/NPT) Homocysteine Assay Factor V Leiden / Molecular Genetics of Thrombophilia Haemophilia Molecular Genetics

13 UK NEQAS for Blood Coagulation: Registrations 1020 participants registered overall in L1/L2 645 (63.2%) in UK NHS and private laboratories 16 (1.6%) manufacturers of reagents/ instruments 359 (35.2%) outside UK in 30 countries

14 UK NEQAS for Blood Coagulation: Test Registrations; Level 1 Prothrombin Time (PT)/INR (Quick and/or capillary methods) PT (diagnostic) Activated Partial Thromboplastin Time (APTT) Heparin Dosage Assessment (HDA) Heparin Assay (HA) Thrombin Time (TT) Fibrinogen evaluation Fibrin(ogen) ) Degradation Products (FDP)/ D-DimerD Dimer Lupus anticoagulant

15 UK NEQAS for Blood Coagulation: Test Registrations; Level 2 Assays Factor II assay Factor V assay Factor VII assay Factor VIII:C assay Factor IX:C assay Factor X assay Factor XI assay Factor XII assay Factor XIII screen Quantitative VIII inhibitor Von Willebrand factor antigen assay Von Willebrand factor RCo (activity) assay

16 UK NEQAS for Blood Coagulation: Test Registrations; Level 2 Thrombophilia Antithrombin antigen assay Antithrombin activity assay Protein C antigen assay Protein C activity assay Protein S total antigen assay Protein S free antigen assay Protein S activity assay Plasminogen assay Activated Protein C resistance assay

17 UK NEQAS for Blood Coagulation: Assistance to the participant Professional Advice Technical Advice Additional samples for troubleshooting Information resource At no additional charge!

18 What is the right answer (target value)? Reference method Expert laboratories Consensus result derived from all laboratory results

19 Target Values n method C method B method A Median INR = / / / INR

20 Target Values : UK NEQAS Aim; To provide comparison with: Overall median Peer group median

21 PEER GROUPS Sample XX/13 : a 51 year old man with mechanical heart valve replacement ( ) median INR % Under dosed % Adequately dosed Inst. Lab PTFib HS Manchester Manchester low

22 Protein C activity Donor homozygous for FV Leiden Clotting-based Chromogenic n u/dl

23 How is performance assessed? n / / / INR

24 How is performance assessed? (2) n / / / INR

25 How is performance assessed? (3) n / / / INR

26 median Within consensus Outwith consensus -15% +15% Outwith consensus

27 median Within consensus Outwith consensus -15% +15% Outwith consensus INR APTT

28 Performance : Persistently outwith consensus Screening tests Outwith consensus >15% from reagent group (if n>10), overall median (if n<10) Persistently outwith consensus >15% from reagent group/overall median x 3 consecutive occasions

29 Assay performance UK NEQAS (BLOOD COAGULATION) 2007 median Within consensus Outwith consensus -15% +15% Outwith consensus FVIII 100u/dl FVIII 10u/dl

30 Assay performance UK NEQAS (BLOOD COAGULATION) 2007 median 10% 25% 25% 10% 5% 5% 5% 5% 5% 5% e d c b a A B C D E grade

31 A-E E grading: FVIII:C assay median = 100u/dl UK NEQAS (BLOOD COAGULATION) 2007 n FVIII:C u/dl Ee Dd Cc Bb Aa

32 Performance Criteria; Factor Assays The overall consensus median is the target value. Individual results ranked in 5 unequal quantiles above and below the median, each quantile designated by a letter depending on ranked distance from the median: A: nearest 25% of results above and below (a)( ) the median; 50% of all results B: next 10% of results above and below (b)( ) the median; 20% of all results C: next 5% of results above and below (c)( ) the median: 10% of all results D: next 5% of results above and below (d)( ) the median; 10% of all results E: 5% of results furthest from median, above and below (e);( 10% of results

33 Cumulative Performance; Factor Assays Grades below the median are shown in lower case, and above the median in upper case, to aid in assessment of bias. Performance is based on grades obtained in two consecutive exercises for any particular test. Performance "outwith" consensus" is defined as a combination of a C (or c ) grade together with an E (or e ) grade, or any combination of D (or d ) and E (or e ) grades (e.g. CE, EC, DD, DE, ED in consecutive distributions of that particular assay).

34 A-E E grades Identifies participants furthest from the median State of the art For imprecise assays, wide acceptable range Survey 114, VWF:RiCoF A grade 63-96u/dl For precise assays, tight range of results Survey 112 Factor X:C A grade 46-52u/dl 10% of labs will receive an E (or e ) grade for any one test

35 Performance: Persistently outwith consensus Assays Outwith consensus Combination of C/E or D/D or D/E or E/E in consecutive surveys Persistently outwith consensus Two consecutive outwith consensus performances e.g. D/D/D; e/c/e; ; D/e/E

36 Assay FVIII:C FXI:C Sample no. 02/06 02/07 Your method One-stage APTT - Your reagent Diagen KPS - Your result 10 - Units u/dl u/dl Your normal range Total no. of participants Median result % deviation Interquartile range ("A" grade) Your performance quantile d - Your cumulative grades e/e/d - Your performance Persistently outwith consensus Your interpretation Abnormal - Overall interpretation (%) - Normal Borderline Abnormal

37 Letter from the Scheme Director Dear Colleague... Can we help? With best regards

38 Case Study : Problems with an individual test Lab. A: INR values consistently high %devn Consecutive surveys

39 Case Study : Problems with an individual test Use Simplastin Excel S on a CA6000 Only 1 other centre uses this combination?appropriate ISI for this combination *Changed reagent to Dade- Behring Innovin Instrumenṯ- Instrument specific ISI %devn * Consecutive surveys

40 Case Study UK NEQAS (BLOOD COAGULATION) 2007 Problems with reference plasmas Lab W Protein C activity with a widely used kit. Grades in 5 surveys A/A/*d/e/c *- introduction of a new primary standard by the lab. Standard provided with 2 values. Wrong value used. Results on average 14% below median in each survey, although assay controls were "within limits".

41 Case Study UK NEQAS (BLOOD COAGULATION) 2007 Further problems with reference plasmas Lab X AT activity with a frozen reference plasma. Grades in 5 surveys A/*/^E/D/E (POC) *- noṉ- non participation due to a change in methodology ^- introduction of a new primary standard by the lab.

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43 Case Study UK NEQAS (BLOOD COAGULATION) 2007 Further problems with reference plasmas Lab X AT activity with a frozen reference plasma. Grades in 5 surveys A/*/^E/D/E (POC) *- noṉ- non participation due to a change in methodology ^- introduction of a new primary standard by the lab. Repeat samples requested from UK NEQAS BC Retested with a major use reference plasma in run Results would have given grades of B/A/A (no POC)

44 Could EQA results be affected by postal delays? 4 weeks at 22 C no change in PT/INR, APTT, FVIII:C, FVII, FV More than 1 week at 37 C C required before results were outwith consensus More than 2 weeks at 37 C PT, APTT lengthen, FV, FVII, FVIII:C activities lost Indian EQA Pilot programme no correlation between delayed receipt of samples and pattern of results

45 Molecular Genetics in the Coagulation laboratory Fewer, specialist centres Wide range of molecular defects Interpretation/reporting of greater importance Genetics testing is now routinely carried out in Coagulation laboratories; increase likely due to improved technology and simplification of technique

46 Molecular Genetics: Getting the right answer UK NEQAS For Molecular Genetic Testing Preston et al; Thromb Haemost 1999; 82: Relatively poor performance of clinical laboratories for DNA analyses. a cause for concern Tripodi et al; Thromb Haemost 2002; 88:690-1.

47 POCT/NPT Quality Control INTERNAL Electronic Lyophilised plasma containing RBC s Lyophilised plasma EXTERNAL UK NEQAS Survey every 3 months 8 samples per year Lyophilised plasma and diluents Comparison with results from hospital laboratory?

48 Registrations in UK NEQAS POC/NPT Programmes October 2007: Germany: 2 Greece: 2 Ireland: 19 Portugal: 5 Sweden: 3 UK: participants

49 Registrations in UK NEQAS POC/NPT Programmes (2) CoaguChek S: 764 participants CoaguChek XS/ +: 487 Hemochron Jr. Sig: Hemochron Jr. Sig: 15 (citrated) 5 (non-citrated)

50 Accreditation & Certification Accreditation standards require: Quality system Quality management Technical competence Certification standards require: Quality system

51 UKAS and CPA UK Accreditation Service Clinical Pathology Accreditation Ltd UKAS and CPA work in a formal partnership in complementary fields UKAS is the recognised as the UK National Accreditation body CPA and CPA (EQA) retain the authority to accredit medical laboratories and clinical EQA schemes in the UK

52 EQA Programme Accreditation By CPA (EQA) UK Ltd Standards traceable to ISO standards Inspection every 2 years UK NEQAS Code of Practice requires all EQA programmes to achieve accreditation UK Government requires all public medical laboratories to register with CPA

53 UK NEQAS for Blood Coagulation Online Result Entry: 2004: Blood Coagulation introduced online result entry; 10% of users returned results online and downloaded reports 2006: 55% of users return results online and download reports 2007: NPT programme now available for result entry and report download through the website

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56 UK NEQAS FOR BLOOD COAGULATION WEBSITE: With thanks to: Dr I Jennings Mrs D P Kitchen Dr S Kitchen Professor I D Walker UK NEQAS BC UK NEQAS BC/STH UK NEQAS BC UK NEQAS BC