“Quality Control” Hematology Analyzers

1. “Quality Control” Hematology Analyzers May 30th 2014 M R Tiwari B.Sc. (Microbiology), PGDMLT, M.Sc.(TQM) Scientific Assistant ‘D’ Hematology, Composite Laboratory, ACTREC, TMC

2. Laboratory test results (Good laboratory practice, GLP) Clinical diagnosis Patient management

3. Good Laboratory Practice Quality can be assured at • Pre-analytical stage • Analytical stage • Post-analytical stage

4. Quality management at the Pre-analytical phase

5. Requisition form • Sample collection & transport • Sample receiving & rejection • Sample preparation QC at Pre-analytical stage

6. Quality Management of the Analytic Phase

7. Terminologies = QC at Analytical stage

8. Neither Accuracy nor Precision QC at Analytical stage

9. Precision Precision No accuracy • Definition Reproducibility of a result • Achieved with • Controls samples • (Commercially procured or whole blood) • When required • Calibration • Daily quality control • After troubleshooting • After change of reagent Precision can be achieved without accuracy… QC at Analytical stage

10. Accuracy Precision & accuracy • Definition Closeness of a result to the true value • Achieved with • Calibrator • When required • Calibration Accuracy cannot be achieved without precision… QC at Analytical stage

11. Basic statistics • Mean – The target • Standard deviation – The acceptable limits (±2SD) • Coefficient of variation (CV %) • variation at different levels can be compared. QC at Analytical stage

12. What is Levey-Jennings (L-J) chart? • X-axis - the days of the month (time interval) • Y-axis. - control observations QC at Analytical stage

13. In 1931, Dr. Walter Shewhart, a scientist at the Bell Telephone Laboratories, proposed applying statistical based control charts to interpret industrial manufacturing processes. In 1950, S. Levey& E.R. Jennings suggested the use in the clinical laboratory. Control Chart's Inventor QC at Analytical stage

14. L-J chart interpretation Westgard rules Dr. James O Westgard QC at Analytical stage

15. Modification of 10x Dr. James O Westgard QC at Analytical stage

16. Hematology analyzers QC at Analytical stage

17. Life of an Haematology analyzer QC at Analytical stage

18. Life of an Haematology analyzer QC at Analytical stage

19. Life of an Haematology analyzer QC at Analytical stage

20. Life of an Haematology analyzer QC at Analytical stage

21. Linearity • WBC (0.02 to 400) • RBC (0.0 to 7.0) • HGB (0.0 to 22.5) • PLT (0.2 to 3500) • RETIC% (0.2 to 24.5) QC at Analytical stage

22. Carryover • Carryover is defined as a number of cells remaining behind following the cycling of a blood sample. • This test is performed to determine if one sample interferes with the accurate analysis of the next sample. • Ideally, carryover shall be very low. • %Carryover = [(L1-L3)/H]x100 • L1– the count of first aspiration of cell-free plasma • L3- the count of third aspiration of cell-free plasma • H – the count of high pool QC at Analytical stage

23. Precision QC at Analytical stage

24. Calibration (setting accuracy) QC at Analytical stage

25. Calibration (setting accuracy) Calibrator Certified Reference Material (CRM) used to calibrate a measurement on an analyzer. Cal-Factors If any deviation from calibration references is observed necessary calibration correction factors are applied to set the accuracy of the instrument. QC at Analytical stage

26. Calibration (setting accuracy) • Pre-calibration check • Total maintenance of the instrument • Reagents (replenish or replace) • Calibrator (Check for expiry) • Controls (Check for expiry) • Calibration procedure • Carryover check • Precision check • Calibration in both • (open and closed modes) • Post-calibration validation • Run calibrator as samples • Run 3 level controls QC at Analytical stage

27. Life of an Haematology analyzer QC at Analytical stage

28. Internal quality control (IQC) Hematology analyzers QC at Analytical stage

29. Daily IQC protocol QC at Analytical stage

30. Daily IQC protocol QC at Analytical stage

31. Daily IQC protocol Warning rule = use other rules to inspect the control points Rejection rule = “out of control” • Do not run patient samples • Identify and correct problem • Do not report patient results until problem is solved and • controls indicate proper performance QC at Analytical stage

32. Daily IQC protocol QC at Analytical stage

33. Other additive IQCs QC at Analytical stage

34. On board additive IQCs • All haematology analyzers • Moving average analysis (Bull’s algorithm) • High end analyzers • WBCP –WBCB • HGB (spectrophotometricaly)-HGB(cellular-laser) • MCHC – CHCM • PMN – (Neutrophils, Eosinophils) • MN – (Lymphocytes, Monocytes) QC at Analytical stage

35. Maintenance of the analyzer • Follow the manufacturer’s manual • Perform maintenance regularly • Daily • Weekly • Biweekly • Monthly • Annually • As if required Maintain record of maintenance QC at Analytical stage

36. Breakdown of analyzer • Try to correct at operator level if possible or • Call the service engineer for help • Maintain a record of any breakdown observed • Nature • Time • Error detected • Corrective action • QC checked • Service report QC at Analytical stage

37. External Quality Assessment(Proficiency testing) QC at Analytical stage

38. Normal Distribution Curve or Gaussian curve Describes events or data that occur symmetrically about the mean. Out of 100 events 68.7 will fall within ±1 SD 95.4 will fall within ± 2 SD 99.7 will fall within ±3 SD QC at Analytical stage

39. Comparative performance evaluation Z-Score QC at Analytical stage

40. If EQAS results are out QC at Analytical stage

41. Quality Management of the Post-analytic phase

42. Delta Check Reference: Lewis: Dacie and Lewis Practical Haematology, 10th ed.,Pg 665 • A formal way of testing for aberrant results is known as `delta check`. • The blood count parameters should not differ from recent tests in the previous 2-3 weeks by more than a certain amount. Assuming that the patient’s clinical condition has not altered significantly QC at Post-analytical stage

43. Alert the clinicianfor report with critical values QC at Post-analytical stage

44. Turn Around Time (TAT) The laboratory takes responsibility for reporting the results within the specified turn around time. The requester i.e. the clinician is notified in case of delay in examination only in such cases where the delay can compromise patients care. Quality Indicator – “TAT shall be monitored on periodic basis for continual improvement” QC at Post-analytical stage

45. Summary… Laboratory test results • Pre-analytical stage • Analytical stage • Post-analytical stage Clinical diagnosis Patient management Quality Good Laboratory Practice

46. Thank you…