Continuing Stability of Center Differences in Pediatric Diabetes Care: do advances in diabetes treatment improve outcome? The Hvidoere Study Group on Childhood Diabetes

Abstract

Objective To re- evaluate the persistence and stability of previously observed differences between pediatric diabetes centers, and to investigate the influence of demography, language communication problems and changes in insulin regimens on metabolic outcome, hypoglycemia and ketoacidosis.

Research Design and Methods Observational cross sectional international study in 21 centers, with clinical data obtained from all participants and HbA1c levels assayed in one central laboratory. All individuals with diabetes aged 11-18 yrs (49.4 % females), with duration of diabetes of at least one year were invited to participate. Fourteen of the centers participated in previous Hvidoere Studies, allowing direct comparison of glycemic control across centers between 1998 and 2005.

Results Mean HbA1c was 8.2 ± 1.4%, with substantial variation between centers (mean HbA1c range 7.4-9.2% ; p<0.001). There were no significant differences between centers in rates of severe hypoglycemia nor DKA. Language difficulties had a significant negative impact on metabolic outcome (HbA1c 8.5±2.0 % vs 8.2±1.4 % ;p<0.05). After adjustement for significant confounders of age, gender, duration of diabetes, insulin regimen, insulin dose, BMI and language difficulties, the center differences persisted, and the effect size for center was not reduced. Relative center ranking since 1998 has remained stable, with no significant change in HbA1c.

Conclusions Despite many changes in diabetes management, major differences in metabolic outcome between 21 international pediatric diabetes centers persist. Different application between centers in the implementation of insulin treatment appears to be of more importance and needs further exploration.