Objective: To examine rates of severe hypoglycemia (SH) in a large population-based cohort of children with type 1 diabetes and relationships to HbA.

Research Design and Methods: Data from 1,683 children (mean [SD] age at diagnosis 10.5 [4.2]; range 1–18 years) from 2000 to 2009 were analyzed from the Western Australian Children's Diabetes Database. Rates of SH were related to HbA1c using negative binomial regression.

Results: A total of 7,378 patient-years of data and 780 SH events were recorded. The rate of SH per 100 patient-years peaked at 17.3 in 2001 and then declined from 2004 to a nadir of 5.8 in 2006. HbA1c <7% was not associated with higher risk of SH (incidence rate ratio 1.2 [95% CI 0.9–1.6], P = 0.29) compared with HbA1c of 8–9%.

Conclusions: In a sample of youth with type 1 diabetes, there has been a decrease in rates of SH and a weaker relationship with glycemic control than previously observed.