Question Are the rates of severe hypoglycemia and diabetic ketoacidosis lower with insulin pump therapy than with insulin injection therapy in young patients with type 1 diabetes? Findings In this population-based observational study including 30 579 young patients with type 1 diabetes, pump therapy, compared with injection therapy, was associated with significantly lower rates of severe hypoglycemia (9.55 vs 13.97 per 100 patient-years) and ketoacidosis (3.64 vs 4.26 per 100 patient-years), and with lower hemoglobin A 1c levels (8.04% vs 8.22%) in a propensity score–matched cohort. Meaning Insulin pump therapy was associated with reduced risks of short-term diabetes complications and with better glycemic control compared with injection therapy. Importance Insulin pump therapy may improve metabolic control in young patients with type 1 diabetes, but the association with short-term diabetes complications is unclear. Objective To determine whether rates of severe hypoglycemia and diabetic ketoacidosis are lower with insulin pump therapy compared with insulin injection therapy in children, adolescents, and young adults with type 1 diabetes. Design, Setting, and Participants Population-based cohort study conducted between January 2011 and December 2015 in 446 diabetes centers participating in the Diabetes Prospective Follow-up Initiative in Germany, Austria, and Luxembourg. Patients with type 1 diabetes younger than 20 years and diabetes duration of more than 1 year were identified. Propensity score matching and inverse probability of treatment weighting analyses with age, sex, diabetes duration, migration background (defined as place of birth outside of Germany or Austria), body mass index, and glycated hemoglobin as covariates were used to account for relevant confounders. Exposures Type 1 diabetes treated with insulin pump therapy or with multiple (≥4) daily insulin injections. Main Outcomes and Measures Primary outcomes were rates of severe hypoglycemia and diabetic ketoacidosis during the most recent treatment year. Secondary outcomes included glycated hemoglobin levels, insulin dose, and body mass index. Results Of 30 579 patients (mean age, 14.1 years [SD, 4.0]; 53% male), 14 119 used pump therapy (median duration, 3.7 years) and 16 460 used insulin injections (median duration, 3.6 years). Patients using pump therapy (n = 9814) were matched with 9814 patients using injection therapy. Pump therapy, compared with injection therapy, was associated with lower rates of severe hypoglycemia (9.55 vs 13.97 per 100 patient-years; difference, −4.42 [95% CI, −6.15 to −2.69]; P < .001) and diabetic ketoacidosis (3.64 vs 4.26 per 100 patient-years; difference, −0.63 [95% CI, −1.24 to −0.02]; P = .04). Glycated hemoglobin levels were lower with pump therapy than with injection therapy (8.04% vs 8.22%; difference, −0.18 [95% CI, −0.22 to −0.13], P < .001). Total daily insulin doses were lower for pump therapy compared with injection therapy (0.84 U/kg vs 0.98 U/kg; difference, −0.14 [−0.15 to −0.13], P < .001). There was no significant difference in body mass index between both treatment regimens. Similar results were obtained after propensity score inverse probability of treatment weighting analyses in the entire cohort. Conclusions and Relevance Among young patients with type 1 diabetes, insulin pump therapy, compared with insulin injection therapy, was associated with lower risks of severe hypoglycemia and diabetic ketoacidosis and with better glycemic control during the most recent year of therapy. These findings provide evidence for improved clinical outcomes associated with insulin pump therapy compared with injection therapy in children, adolescents, and young adults with type 1 diabetes. This population-based cohort study compares rates of severe hypoglycemia and diabetic ketoacidosis among children, adolescents, and young adults with type 1 diabetes managed with insulin pump therapy vs insulin injection therapy.
