General practice management of type 2 diabetes

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Diabetes is identified as one of the medical conditions that may impair driving ability. Diabetes and diabetes medications may alter the capacity to drive safely.

Impairment can occur due to unexpected hypoglycaemia (main hazard) for drivers with type 2 diabetes on glucose-lowering medications and/or sensory or end-organ complications, particularly reduced vision and sensation in the feet.

Other comorbidities such as sleep apnoea and cardiovascular problems have substantial implications.

Drivers with diabetes must meet specific national standards. Certain criteria must be met to ensure that their health status does not increase the risk of a crash. Medical assessment should include:

  • therapeutic regimens (eg diabetes treated by any glucose-lowering agents including insulin)
  • commercial or private standards
  • satisfactory control of diabetes
  • hypoglycaemic unawareness
  • recent severe hypoglycaemic event
  • comorbidities and end-organ complications.

In practice

Evaluate patients with diabetes on their capacity to drive against national standards.

Medical standards for licensing and clinical management guidelines for commercial and private vehicle drivers are contained in the Austroads and National Transport Commission document Assessing fitness to drive for commercial and private vehicle drivers 264 A flowchart to assist with the management of diabetes and driving can be found on page 59 of the above document. The document is currently being updated and the new version will be published on 1 October 2016.

As each state and territory has differing medical assessment instructions, check with the relevant transport authority for requirements in respective states.

Specialist referral is usually required for commercial licences if the patient is on oral glucose-lowering agents or insulin therapy. Licensing review periods are also determined by therapeutic regimes. People with diabetes on commercial licences are subject to yearly specialist review if they are on any form of glucose-lowering therapy, unless they are on metformin alone, where ongoing fitness to drive may be assessed by the treating GP by mutual agreement with the treating specialist. The initial recommendation of a conditional licence must, however, be based on the opinion of a specialist in diabetes.

An HbA1c level of ≥75 mmol/mol (≥9.0%) should not be used administratively by licensing authorities to deny eligibility for a licence in the absence of a medical review. There is no strong evidence of high average blood glucose levels and driving risk. The new national standards, which is due for publication later in 2016, will likely not include an upper HbA1c threshold of concern regards driving requirements.

These are national standards, so it is important to contact the driving authority in individual states and territories as variations to the national standards do exist.

The Diabetes and driving: Above 5 to drive! consumer booklet  provides a checklist and offers advice for people with diabetes to ensure that they have safe blood glucose levels before they drive. The importance of taking extra precautions to maximise road safety and reduce risks of road accidents caused by hypoglycaemic incidents is highlighted and should be actively promoted.

For example, drivers are required to perform a blood glucose check before they drive and again during the journey if driving for more than two hours.

Diabetes Australian and RACGP logo's
  1. Austroads and National Transport Commission. Assessing fitness to drive. 4th edn (amended up to 30 June 2014). Sydney: Austroads and NTC, 2012.