Quality control in clinical laboratories

QC

1. Quality Control In Clinical Laboratory

2. Learning Outcomes At the end of the presentation, participants should Understand the basic principles of Quality control Understand the importance for internal and external quality control schemes

3. Quality is.... invisible when GOOD impossible to ignore when BAD

4. DEFINITIONS Quality Quality Control Quality Assurance Total Quality management Quality Assessment

5. Quality Control In Clinical Laboratory

6. No result is better than wrong result

7. Analytical Processes Non analytical processes Pre-analytical Post-analytical LABORATORY PROCESSES

8. Patient Treatment Interpretation Data flow Lab analysis Orders Collection Transportation

9. DEFINITIONS Quality The characteristics of a product or service and its ability to satisfy fulfill customer needs (conformance to customer requirements) Quality assurance Planned and systematic activities to provide adequate confidence that requirements for quality will be met Total Quality management Overall management function that determine Quality policy objectives Responsibilities Implementation

10. FUNDAMENTALS OF TQM Customer focus Management commitment Training Process capability & control Measurement using quality–improvement tools

11. 5Q Cycle

12. PDCA CYCLE Plan Check Do Act

13. GOALS QUALITY

14. DEMING’S CONCEPT Quality improvement reduces waste & increase productivity Reduces costs Provides a competitive advantage by customer satisfaction

15. COSTS OF CONFORMANCE & NONCONFORMANCE

16. COSTS OF CONFORMANCE & NONCONFORMANCE

17. ANALYTICAL QUALITY CONTROL

18. DEFINITIONS Quality control Steps taken by the lab to ensure that the tests are performed correctly QC procedures The protocol & materials necessary for an analyst to assess whether a method is working properly & patient test results can be reported. No of control measurements The decision criteria (control rules)

19. DEFINITIONS Internal quality control Procedures adopted by the lab for checking day to day accuracy & precision of all procedures and equipment External quality control A quality program in which specimens are submitted to labs for analysis & results of an individual lab are compared with the results of participating labs or reference method

20. PRECISION & ACCURACY

21. INTERNAL QUALITY CONTROL PROGRAM Running samples of known values Calculation mean and standard deviation Decision criteria (Range: mean ±2SD, or 3SD) Run QC daily/ as per requirement/SOP Plotting them on control charts/LJ charting Interpretation by Westgard multi-rule Record in registers/ proforma

22. Daily maintenance schedule Record any change Frequency of known QC samples and calibrators Frequency of blind QC samples Run QC samples before patient samples Normal and abnormal control INTERNAL QC CHECKS

23. Levey –Jennings Control Charts If precision remains unchanged then 68% fall within 1SD and 95% values fall within 2SD range One in 20 readings crossing 2SD One in 1000 readings crossing 3SD

24. QC Profrma

25. Consecutive daily measurements of controls are used to calculate the mean and SD value These values are plotted on a graph paper showing horizontal lines of mean 1SD, 2SD and 3SD. If precision remains unchanged then 68% fall within 1SD and 95% values fall within 2SD range Permissible limits are one in 20 readings crossing 2SD limit and 3 in 1000 readings crossing 3SD limit Levey –Jennings Chart

26. Levey –Jennings Control Charts

27. SHIFT & TREND

28. Levey –Jennings Control Charts

29. How to apply QC rules Ctr Rule Days Action Type L1 10 x 2 1s 3-12 13 Rejection Warning Systematic Random L2 3 1s 2 1s 3 13 Rejection Warning Random Random BTW R 4s 13 Rejection Random

30. INTERNAL QC REVIEW Daily Weekly Monthly Annual Periodic

31. DAILY QC REVIEW Decision about validity of batch results Record of QC result and decisions Error detection and correction Log book maintenance Communication with physicians

32. TYPE ERRORS Predictable Unpredictable

33. RANDOM ERROR Improper mixing of reactions constituents Contamination during testing Pipetting & glassware variation Electrical Supply Variation in temp and time control Variation in cuvettes Change of technician Spectrophotometer lamp detoriation

34. SYSTEMATIC ERROR Calibration Detoriation of lamp Improper reconstitution of controls Error in control concentration Reagent contamination Long term Instrument problems Inadequate mixing of controls/Controls left at suboptimal temperature for too long Lot number change

35. SHIFT & TREND Abrupt Change Gradual Detoriation

36. WEEKLY QC REVIEW Short term changes Trends & shifts Weekly maintenance checks

37. MONTHLY QC REVIEW Check monthly maintenance Shifts or trends Evaluate monthly average against target average (temporary and final ) Significant change limit Check against QC goals Monthly patient average limit

38. MONTHLY QC REVIEW Compare monthly SD with USD If difference between target average and monthly average is more than 1 USD Statistical significance? Medical significance? Operational significance?

39. BLIND SAMPLES Blind quality control samples Blind patient samples Purpose

40. QUALITY CONTROL MATERIAL Commercial , lyophilized pool material Commercial, low temperature liquid serum pools Frozen, pooled patient sample QC pool serum should be free of: Hepatitis B and C HIV 1-2 year supply

41. QUALITY CONTROL OF REAGENTS Date of preparation Expiry date Requirement for refrigeration Freeze thaw cycles Radioactivity, flammability One container should be reserved for one reagent only Reagents should be free from dirt and direct sun light

42. CALIBRATION Controls and calibrators Matrix effect Sufficient for 1-2 years Verification of new calibrators Duplicate measurements QC samples Patient samples Average SD test Significant difference

43. Precision Selection of specimens Arrangement of specimens Effect of concentration Between-batch CV Within-batch CV

44. Interferences Calibration Nonlinearity Contamination Uncorrected blank Bias Instrumental shifts Lack of Precision Operator Bias Matrix effects Reagent Instability

45. CORRECTION OF THE ERRORS Stepwise checking Control material Standards Sampling system Measuring system like spectrophotometers Reagents Performance of analytical system

46. EXTERNAL QUALITY CONTROL Procedures used to evaluate the performance of different laboratories is known as external QC Maintenance of long-term accuracy of the analytical methods EQAS External Quality Assurance System REQAS CAP NEQAPP National External Quality Assurance Program Pakistan Also called PT

47. PROFICIENCY TESTING The process in which stimulated specimens made from a pool are analyzed by a lab The results of this procedure are evaluated to determine the quality of the lab’s performance It is used as an objective method for lab accreditation

48. Lab Accreditation Advantages Compulsory participation Ensures action following poor performance Ensures employment of qualified staff Laid down acceptability targets Disadvantages Destroys the educational aspect of scheme Bureaucratic action to deal with poorly performing laboratories

49. Conclusion

50. Conclusion However, good laboratory practices and compliance with strategies for error prevention can lead to a substantial reduction in pre-analytical errors Continuous trg of staff

51. THANK YOU