Frier et al published a review that evaluated various published cohorts of people with type 1 diabetes and the frequency of severe hypoglycemia.1

This review included 10 published studies in people with type 1 diabetes mellitus (T1DM) that

• were both prospective and retrospective in design
• evaluated between 100 and 3813 people
• were older than 14 years of age
  
• had a duration of follow-up between 1 week and 19 months
• had reported mean glycated hemoglobin values of 7.3% to 10.7%
• had severe hypoglycemia defined as the need for third party assistance or glucagon/intravenous glucose, and
• had various insulin regimens with the majority ranging from twice daily injections to 4 or more injections daily or continuous subcutaneous insulin infusion.1

Using data from a variety of published cohorts summarized in the review by Frier et al, the mean incidence of severe hypoglycemia events in people with T1DM using insulin was approximately 1.5 events/person/year (range, 0.2-3.2 events/person/year).1

Using data from a variety of published cohorts summarized in the review by Frier et al, the prevalence of severe hypoglycemia events in people with T1DM using insulin was approximately 29% (range, 3%-46%).1