New Hb A1c Numbers Presentation
- 1. Understanding the New IFCC HbA1c Numbers
- 2. Clear understanding of HbA1c Clear understanding of the new values for reporting HbA1c and what they mean Clear understanding of what is going to happen and what to do Training outcomes
- 3. Introduction What is HbA1c? What period is measured? Why is HbA1c important? Current reporting of HbA1c New standardisation of HbA1c How to read the new values and compare them with the old UK Consensus and plan Questions Agenda
- 5. What is HbA1c HbA1c is simply haemoglobin to which circulating glucose has bound Glucose + haemoglobin Red blood cell Glycohaemoglobin
- 6. HbA1c is Glycosylated Haemoglobin 14% 7% 9% The HbA1c test reports the amount of HbA1c as a proportion of the total haemoglobin Glucose + haemoglobin Red blood cell Glycohaemoglobin
- 7. What period does HbA1c measure?
- 8. March February May April May 6.25% April March Feb March April April May 8.33% May 12.5% May 25.0% May 52% April 27% March 14.5% Feb 6.5% Test at end May What period is measured ? Month red blood cell produced Total influence of monthly blood glucose on HbA1c
- 9. Why is HbA1c so important?
- 10. Why is HbA1c so important? Microvascular complications 37% 14% Deaths related to diabetes Microvascular complications HbA 1c 37% 14% Deaths related to diabetes Microvascular complications HbA 1c 37% 14% Deaths related to diabetes Microvascular complications HbA 1c 37% 14% Deaths related to diabetes 21% Microvascular complications HbA 1c 37% 14% Deaths related to diabetes 21% Microvascular complications HbA 1c 37% 14% Deaths related to diabetes 21% 1% Myocardial infarction DCCT showed that HbA1c is the best long-term marker of diabetes control Better control of HbA1c leads to better outcomes in people with diabetes Stratton IM, et al . BMJ 2000; 321:405–412.
- 11. What is DCCT Alignment of HbA1c?
- 12. What is DCCT Alignment? The DCCT is the largest and most significant study into the long term control of diabetes and outcomes in type 1 diabetes The UKPDS is the equivalent landmark study into type 2 diabetes, and uses the same reference system for HbA1c All UK labs standardise their activities so that results are aligned to DCCT This means that data from DCCT, UKPDS and other long term studies are cross-compatible, and the patient’s risk of complications can be inferred from their results.
- 14. Targets based on DCCT / UKPDS findings: NICE QOF IDF DCCT Aligned Targets 6.5 to 7.5% < 6.5% 85% < 10% 50% < 7.4% NICE <6.5% Increased risk of arterial disease
- 15. Why change from DCCT Alignment? Since the DCCT, the method used then for measuring HbA1c has been found to have interferences causing a falsely high number. Test results from newer methods can report the accurate value without interferences but have always been adjusted to give results aligned to the old DCCT method. Original DCCT method New modern methods DCCT aligned 8.0% 6.4% 8.0% Scientists and clinicians have agreed that it is no longer tenable to report results which they know to be falsely elevated 1.6% Interferences
- 16. What will replace DCCT alignment? International Federation of Clinical Chemistry and Laboratory Medicine
- 17. Scientists and clinicians have been working for more than 10 years to produce a gold-standard, interference free method for HbA1c The new calibration method, without interferences, gives values approximately 1.5% lower than the DCCT values Unfortunately the two numbers are still similar enough in appearance to cause confusion, so a decision has been taken to change the units of reporting the new values in order to avoid any problems The new ‘IFCC standardised’ results will be written in units of mmol/mol IFCC Calibration
- 18. What is the relationship between IFCC and DCCT?
- 19. What is the relationship? For example So to help avoid confusion IFCC HbA1c will be reported as mmol/mol rather than % DCCT HbA1c 8% IFCC HbA1c 6.4% = DCCT HbA1c 8% IFCC HbA1c 64 mmol/mol =
- 20. Conversion Graph DCCT to IFCC
- 21. Conversion table DCCT to IFCC DCCT % HbA1c IFCC mmol/mol HbA1c 4 20 4.5 26 5 31 5.5 37 6 42 6.5 48 7 53 7.5 58 8 64 8.5 69 9 75 9.5 80 10 86 10.5 91 11 97 11.5 102 12 108 12.5 113 13 119 13.5 124 14 130 14.5 135 15 140 15.5 146 16 151 16.5 157 17 162
- 22. Key treatment targets - NICE
- 23. Key treatment targets - IDF
- 24. Key treatment targets - QOF DCCT %HbA1c IFCC mmol/mol HbA1c 6 42 6.5 48 7 53 7.4 57 8 64 8.5 69 9 75 9.5 80 10 86 50% 85%
- 25. Converting DCCT to IFCC - A quick trick 7% = 53mmol/mol For whole numbers between 4 and 13 Minus two, minus two... 7 - 2 = 5
- 26. Converting DCCT to IFCC - A quick trick 7% = 53mmol/mol For whole numbers between 4 and 13 Minus two, minus two... 7 - 2 = 5 5 - 2 = 3
- 27. What has been agreed?
- 28. Worldwide Consensus Statement published at the end of 2007 What has been agreed globally ?
- 29. What has been agreed UK? UK Consensus Statement published July 2008
- 30. UK Consensus Statement Summary HbA1c test results should be standardised using the IFCC reference method (already completed by manufacturers) Extensive education programmes should be developed for all healthcare professionals HbA1c results should be reported in IFCC (mmol/mol) units and DCCT (%) units Parallel reporting will start from June 2009 and continue for 2 years After this time it is envisaged that laboratories will report only IFCC units
- 31. What happens now? From January of 2009 some UK labs will start producing reports with both DCCT % and IFCC mmol/mol values Primary Care reporting systems already have the facility to accept DCCT aligned results Software releases on 1st April 2009 will allow the incorporation of the new IFCC aligned results into patient records
- 32. Reporting Formats HbA1c level = 8.0% (DCCT aligned) HbA1c level = 64 mmol/mol (IFCC aligned) This is the format which will appear in primary care reporting systems Internal hospital reports and results printed directly from HbA1c analysers may appear in a slightly different format
- 34. Summary and Conclusion The appearance of HbA1c results is going to change The new values will look very different but can easily be compared to the familiar ones You will see the changes in the next few months You have two years to get used to the new values (Dual reporting) for treatment targets for interpretation of results Questions?
- 35. Clear understanding of HbA1c Clear understanding of the new values for reporting HbA1c and what they mean Clear understanding of what is going to happen and what to do Training outcomes
- 36. Understanding the New HbA1c Numbers
Editor's Notes
- #2: From June 2009 there is to be a change to the way that HbA1c measurement test results are reported. This change could lead to potential confusion amongst diabetes nurses in secondary and primary care, and their patients. There could be a real risk that patient control could deteriorate due to potential lack of understanding of the new units by patients and healthcare professionals, leading to complications. The good news is that for a while to come the reports you see will still show the ‘old’ numbers alongside the new, giving you the chance to get used to the new numbers. The good news is that this presentation, which you can have a copy of, explains everything so you can be comfortable with what’s happening.