Clarke Score

The Clarke Score is used to check hypoglycemia perception in patients with diabetes mellitus. The «Swiss Society of Endocrinology and Diabetology» recommends, among other things, the use of the Clarke Score to assess the risk of hypoglycemia regarding fitness to drive and driving ability in patients with diabetes mellitus.

Choose the statement that describes you best.

I always have symptoms when my blood sugar is low. I sometimes have symptoms when my blood sugar is low. (+1) I never have symptoms when my blood sugar is low. (+1)

Have you lost symptoms of hypoglycemia that used to occur when your blood sugar is low?

No Yes (+1)

In the past 6 months, how often have you had severe low blood sugar episodes in which you were confused, disoriented, and unable to self-medicate but without becoming unconscious?

Never 1–2× (+1) Every 2nd month (+1) Every month (+1) More than once a month (+1)

In the past year, how many severe low blood sugar episodes have you had in which you were unconscious, had seizures, or required a glucagon or glucose injection?

None Once or more (+1)

In the last 4 weeks, how often have you had blood sugar levels below 3.9 mmol/l (70 mg/dl) with symptoms?

Never 1–3× 1× per week 2–3× per week 4–5× per week Almost daily

In the last 4 weeks, how often have you had blood sugar levels below 3.9 mmol/l (70 mg/dl) without symptoms?

Never 1–3× 1× per week 2–3× per week 4–5× per week Almost daily

How far does your blood sugar have to drop for you to notice symptoms?

3.3 – 3.8 mmol/l / 59 – 68 mg/dl 2.8 – 3.2 mmol/l / 50 – 58 mg/dl 2.2 – 2.7 mmol/l / 40 – 49 mg/dl (+1) < 2.2 mmol/l / < 40 mg/dl (+1)

How reliably can you tell from your symptoms that your blood sugar is low?

Always Frequent Sometimes (+1) Rarely (+1) Never (+1)

Clarke Score:

Interpretation

Points	Assessment
≤ 3	Normal hypoglycemia perception
≥ 4	Reduced hypoglycemia perception

References

Lehmann R, Czock A, Egli M et al. (2017) Schweizerische Gesellschaft für Endokrinologie und Diabetologie. Richtlinien bezüglich Fahreignung und Fahrfähigkeit bei Diabetes mellitus. Abgerufen von https://www.sgedssed.ch