Medicines Optimisation and LTCsTeam

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ToAll Practices, Lambeth CCG

CcCommunity Pharmacists, Lambeth CCG

Re. Identification of people at high risk of diabetes, interpretation of HbA1c results.

Please share this letter with the relevant clinical staff in your practice.

Since 2012, NICE and the NHS Health Checks programme have recommended the use of HbA1c blood testing for the diagnosis of diabetes. The HbA1c blood test is also used to stratify those at increased risk of developing type 2 diabetes. This is known as pre-diabetes or Impaired Glucose Regulation. The HbA1c blood test is also more traditionally used for the routine monitoring of glycaemic control in people with Diabetes Mellitus.

This “dual use” of HbA1c has led to some confusion as many laboratories in the country do not include the new diagnostic use of HbA1c in the text or reference range that accompanies the numerical test result thus values at the lower end of the pre-diabetes range (42mmol/mol) have been reported as normal.

The interpretation of an HbA1c value of 42mmol/mol depends upon the context under which the test has been requested:

  • Individual known to have diabetes. For glycaemic control or response to treatment a value of 42mmol/mol is considered to be within the normal range. This is currently indicated in reference range from the laboratory that accompanies the result.
  • Individual at high risk of developing type 2 diabetes.When using HbA1c for diagnostic purposes, a value of 42mmol/mol (range 42-47mmol/mol) indicates that the individual is at high risk of developing type 2 diabetes.
    Action to be considered in individuals at high risk :
  1. Follow the London Strategic Clinical Networks consensus approach to the diagnosis of type 2 diabetes (attached).
  2. Read code - 14O80 which indicates High Risk of Diabetes Mellitus,
  3. Referral to an intensive lifestyle management programme, designed to reduce their subsequent risk of developing type 2 diabetes – STEPs programme (referral forms and guidance will be uploaded to DXS).

Nationally, the Association of Clinical Biochemists are now looking to address the way diagnostic test results for HbA1c are reported, by providing clarity to laboratories across the country. This will hopefully be reflected in the communication of results to primary care in due course.

I hope this provides some clarification. If you have any questions please contact Dr Mark Chamley, GP Lead, Diabetes Intermediate Care Team

Regards,

Dr Neel Basudev

GP, Clinical Network Diabetes Lead, Lambeth CCG

cc.Dr John Balazs, GP, Board Member Lambeth CCG
Dr Mark Chamley, Partner Crown Dale Medical Centre and DICT.

Moira McGrath, Director of Integrated Commissioning

Dr Sarah Corlett, Lambeth & Southwark Public Health Team

Vanessa Burgess, Assistant Director Lambeth CCG

CCG Chair: Dr Adrian McLachlan Chief Officer: Andrew Eyres