Driving and diabetes
Most people with diabetes also drive, and will require your assistance on advice as to when to they should inform the DVLA about their diabetes and on completing DVLA documentation.
Downloadable resources and leaflets are available on the TREND website
There are 2 groups of vehicle licences, Group 1 entitlement – car, motorcycle which is what most people will need and Group 2 entitlement vocational – lorries, buses.
Diabetes treated by diet, or tablets other than sulfonylureas (SUs) or glinides
When diabetes is treated by diet, or diet and medication which has no likelihood of causing hypoglycaemia (metformin, acarbose, the DPP4 agents and dapagliflozin or canagliflozin, or GLP analogue when used as monotherapy or in combination, but not with sulphonylrea, or insulin, there is no requirement to inform the DVLA. All people with diabetes will need to report changes in vision and visual field as would any other person.
Diabetes treated by SUs or glinides which may cause hypoglycaemia
When diabetes is treated managed by tablets (sulphonylureas and glinides) which carry a risk of inducing hypoglycaemia, the DVLA does not need to be informed. It is be appropriate to monitor blood glucose regularly and at times relevant to driving to enable the detection of hypoglycaemia. People with diabetes must be under regular medical review. If there is a second episode of hypoglycaemia requiring the assistance of another person within the preceding 12 months, the DVLA must be informed.
Group 2 entitlement
For people seeking Group 2 entitlement vocational, the DVLA must be informed, but will be entitled to drive if they have no episode of hypoglycaemia requiring the assistance of another person has occurred in the preceding 12 months, have full awareness of hypoglycaemia, regularly monitors blood glucose at least twice daily and at times relevant to driving, demonstrate an understanding of the risks of hypoglycaemia, have no other debarring complications of diabetes such as a visual field defect, and be under regular medical review.
When insulin is used for a short period such as treatment for gestational diabetes, post-myocardial infarction or with a course of steroids, there is no requirement to inform the DVLA for Group 1. However, for Group 2 entitlement the DVLA must be informed.
Diabetes treated with insulin
When people with diabetes are treated with insulin, the requirements are more arduous. All will need to inform the DVLA.
The requirements to drive are that there are fewer that 2 episodes of severe hypoglycaemia in a 12 month period. When a Group 1 driver (car/motorcycle) has had 2 or more episodes of hypoglycaemia requiring assistance from another person at anytime (including when sleeping) in a year, they must inform DVLA, and be advised not to drive. A Group 2 driver (bus/lorry) with one or more episode(s) of hypoglycaemia requiring the assistance of another person in the previous 12 months must inform DVLA and be advised not to drive. Hypoglycaemia requiring assistance from another person at any time of day constitutes an episode for reporting purposes. The requirement of assistance would include admission to A and E, treatment from paramedics, or from a partner/friend who has to administer glucagon or glucose because the patient cannot do so themselves. It does not include another person offering or giving assistance, in circumstances where the patient was aware of his/her hypoglycaemia and able to take appropriate action independently. It follows that when filling in the questionnaire that great care is taken to elicit an exact history of each episode, and it would be sensible to chart this information carefully in their records.
Primary care teams should consider referral to the specialist team for patients who have suffered a single hypoglycaemic attack requiring assistance, where a second episode might result in loss of employment.
Many patients do not inform their doctor about hypoglycaemia. However reports of hypoglycaemia may be sent from the ambulance team or A and E to the patient’s registered GP. If you are informed that a patient has required treatment to manage hypoglycaemia, it would be sensible to see the patient and inquire about the frequency and severity of hypoglycaemia. For Group 1 drivers, with two episodes of hypoglycaemia requiring the assistance of another person within the previous 12 months, the doctor must inform the patient that they need to notify DVLA and advise the patient not to drive. This advice should be charted. A Group 2 driver with one such episode in the previous 12 months should be advised not to drive and notify DVLA. A referral to specialist care would be appropriate.
In some interviews, it may be suspected that severe nocturnal hypoglycaemia is present in a patient sleeping on their own, but not witnessed or treated. This would not necessarily constitute an episode for reporting. However if the clinician had concerns it may be appropriate to advise the patient to notify DVLA. Paradoxically, people sleeping on their own, with nocturnal hypoglycaemia may be advantaged in terms of maintaining their driving licence, although clearly not in terms of overall well-being. Similarly, data while using continuous glucose monitoring devices or other evidence of hypoglycaemia may not constitute evidence to stop driving in the absence of symptoms unless the clinician has concerns. However, where hypoglycaemia with reduced awareness is suspected, a referral to specialist care would be appropriate.
Most clinicians will have experienced interviews when the patient has current or describes previous biochemical evidence of asymptomatic hypoglycaemia (below 3mM/l) on capillary glucose testing. On occasion, later laboratory blood testing may demonstrate hypoglycaemia with apparently normal cognitive function. This biochemical evidence of hypoglycaemia shows that the patient has a degree of hypoglycaemia unawareness. They are likely to have cognitive dysfunction during hypoglycaemia, and are at increased risk of severe hypoglycaemia. Whilst such episodes do not constitute an episode of hypoglycemia for reporting purposes, they do require a clinical response. When found, if driving is planned, the hypoglycaemia should be corrected, and the patient advised not to drive until this has been treated. Again, evidence of reduced awareness of hypoglycaemia will require treatment regime review and a referral to specialist care would be appropriate.
There are no specific guidance as to what constitute hypoglycaemic unawareness, but if there is evidence for cognitive dysfunction around 3 mmol/l, people who are asymptomatic when under this glucose concentration they are at risk of awareness.
Some people will not inform the DVLA that they are having hypoglycaemia requiring assistance. When any doctor is aware that a patient who has been advised to stop driving continues to do so, according to GMC advice, they should advise the patient not to drive and the doctor should notify DVLA. It would be good practice to confirm this conversation in writing to the patient so that there is no doubt about the advice. This should be documented in the patient notes. It is up to the DVLA to revoke/renew license. The doctor may also want to inform the patient that their insurance is no longer valid. If the doctor feels the patient is not fit to drive or they have concerns but are not sure if the patient is fit to drive they should advise the patient to notify DVLA and document this in the notes.