Glycemic Control Variations for Children, Adolescents With T1D in High-Income Countries

A mother measuring her daughter's glucose
A mother measuring her daughter’s glucose
Investigators examined glycemic control variations in 8 high-income countries from multicenter registries in children with type 1 diabetes.

The mean glycated hemoglobin (HbA1c) level of children and adolescents with type 1 diabetes was lowest in Sweden, Denmark, and Norway, with the smallest between-center variations, compared with children and adolescents with type 1 diabetes at centers in the United States, Germany, England, Wales, and Austria, according to a study published in Diabetes Care

The study set out to describe the variations in glycemic control within 8 high-income countries (1 in the United States and 7 in Western Europe) and explore how these variations may be attributable to center differences.

Data from all countries were taken from national, population-based registries or audits covering at least 80% of children with type 1 diabetes, except for the US data, which were taken from a clinic-based registry.

All children (N=64,666) had a similar age and sex profile. Using fixed and random-effects models, study investigators calculated variations in HbA1c, as well as the association between glycemic control and within center variations.

The lowest mean HbA1c was found in Sweden (59 mmol/mol [7.6%]), which, together with Denmark and Norway, also had the smallest between-center variations (ICC ≤ 4%). The next lowest mean Hb1Ac levels were found in Austria and Germany (61–62 mmol/mol [7.7–7.8%]), but these countries also had the biggest between-center variations (ICC ∼15%). The centers in the United States, England, and Wales had high mean values with low-to-moderate center variations. In pooled analysis, the significance of these differences between countries persisted after adjustment for center effects and characteristics of children (P<.001). Across all countries, variable glycemic results were associated with higher HbA1c.

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The improved glycemic outcomes found in Sweden can most likely be attributed to a system-wide collaboration between quality registries, which was established to promote performance improvement for pediatric diabetes. The nationwide program includes transparent public reporting of performance within centers, performance data used for professional development and as a clinical tool, and active center participation in collaborations for quality improvement.

One limitation of the study that is particularly applicable to clinicians in the United States is that the United States data were taken from a selective group of clinics and may therefore not be directly comparable to data taken from population-based registries. 

Nevertheless, study investigators conclude “the distribution of glycemic achievement across centers within countries should be considered, alongside national mean values, in developing informed policies that drive quality improvement.”


Charalampopoulos D, Hermann JM, Svensson J, et al. Exploring variation in glycemic control across and within eight high-income countries: a cross-sectional analysis of 64,666 children and adolescents with type 1 diabetes [published online April 12, 2018]. Diabetes Care. doi: 10.2337/dc17-2271