Motor vehicle driving among diabetics taking insulin and non-diabetics.

Objective: To determine whether rates of road traffic accidents were higher in diabetics treated with insulin than in non-diabetic subjects.
Design: Controlled, five year retrospective survey.
Setting: Diabetic, dermatology, and gastroenterology outpatient clinics.
Patients: 596 Diabetics treated with insulin (354 drivers) aged 18-65 attending two clinics and 476 non-diabetic outpatients (302 drivers).
Main Outcome Measures: Rates of accidents in diabetic and non-diabetic subjects.
Results: A self completed questionnaire was used to record age, sex, driving state, and rates of accidents and convictions for motoring offences among diabetic and non-diabetic volunteers. For the diabetic volunteers further information was obtained on treatment, experience of hypoglycaemia, and declaration of disability to the Driving and Vehicle Licensing Centre and their insurance company. Accident rates were similar (81 (23%) diabetic and 76 (25%) non-diabetic drivers had had accidents in the previous five years). A total of 103 diabetic drivers had recognised hypoglycaemic symptoms while driving during the previous year. Only 12 reported that hypoglycaemia had ever caused an accident. Overall, 249 had declared their diabetes to an insurance company. Of these, 107 had been required to pay an increased premium, but there was no excess of accidents in this group.
Conclusions: Diabetic drivers treated with insulin and attending clinics have no more accidents than non-diabetic subjects and may be penalised unfairly by insurance companies.