Prevalence of intentional under- and overdosing of insulin in children and adolescents with type 1 diabetes

Schober E, Wagner G, Berger G, Gerber D, Mengl M, Sonnenstatter S, Barrientos I, Rami B, Karwautz A, Fritsch M, on behalf of the Austrian Diabetic Incidence Study Group. Prevalence of intentional under‐ and overdosing of insulin in children and adolescents with type 1 diabetes. Objective: The aim of this study was to evaluate the prevalence of insulin under‐ and overdosing in paediatric patients. Research design and methods: Cross‐sectional study including 241 patients (age 14.0 + 2.7 yr, 42.5% males) with type 1 diabetes from 21 diabetic outpatient clinics. Haemoglobin A1c (HbA1c), height, and weight were available from clinical records. Patients were interviewed with the Diabetes Self‐Management Profile (DSMP) interview. T test, U test, and chi‐squared test were used for comparison. Results: On the basis of the DSMP, 103 (42.7%) patients (group A) showed adherence to the therapeutic insulin regimen, while 71 (29.5%) patients (group B) confessed intentional over and/or under‐dosing of insulin. Sixty‐seven (27.8%) adolescents (group C) reported management problems leading to unintended inappropriate insulin dosages. In group B, 55 (22.8%) injected higher insulin doses and 58 (24.1%) omitted insulin. Patients of group B compared to group A were older 15.0 (±2.5) vs. 14.0 (±2.5) yr (p < 0.01), older at onset 9.5 (±3.6) vs. 8.3 (±3.8) yr (p = 0.05), were more often girls (69 vs. 45.6%), had a higher actual HbA1c (8.7 ± 1.7 vs. 7.8 ± 1.2%), and a higher average HbA1c in the previous year (8.3 ± 1.6 vs. 7.9 ± 1.2%) (p < 0.01). No significant differences could be found between group A and group C. Conclusion: Intentional overdosing of insulin is almost as prevalent in children and adolescents as insulin omission. Females are more at risk.