Persistent Differences Among Centers Over 3 Years in Glycemic Control and Hypoglycemia in a Study of 3,805 Children and Adolescents With Type 1 Diabetes From the Hvidøre Study Group

Abstract

OBJECTIVE -Twenty-one international pediatric diabetes centers from 17 countries investigated the effect of simple feedback about the grand mean HbA 1c level of all centers and the average value of each center on changes in metabolic control, rate of severe hypoglycemia, and insulin therapy over a 3-year period.RESEARCH DESIGN AND METHODS -Clinical data collection and determination of HbA 1c levels were conducted at a central location in 1995 (n ϭ 2,780, age 0 -18 years) and 1998 (n ϭ 2,101, age 11-18 years).RESULTS -Striking differences in average HbA 1c concentrations were found among centers; these differences remained after adjustment for the significant confounders of sex, age, and diabetes duration. They were apparent even in patients with short diabetes duration and remained stable 3 years later (mean adjusted HbA 1c level: 8.62 Ϯ 0.03 vs. 8.67 Ϯ 0.04 [1995 vs. 1998, respectively]). Three centers had improved significantly, four centers had deteriorated significantly in their overall adjusted HbA 1c levels, and 14 centers had not changed in glycemic control. During the observation period, there were increases in the adjusted insulin dose by 0.076 U/kg, the adjusted number of injections by 0.23 injections per day, and the adjusted BMI by 0.95 kg/m 2 . The 1995 versus 1998 difference in glycemic control for the seven centers could not be explained by prevailing insulin regimens or rates of hypoglycemia.CONCLUSIONS -This study reveals significant outcome differences among large international pediatric diabetes centers. Feedback and comparison of HbA 1c levels led to an intensification of insulin therapy in most centers, but improved glycemic control in only a few.

Establishing glycaemic control with continuous subcutaneous insulin infusion in children and adolescents with type 1 diabetes: experience of the PedPump Study in 17 countries

“…This study has highlighted the marked variations in patterns of pump use between centres, for example in terms of the number of daily boluses and the proportion of the daily dose given in pump form. This is consistent with the finding in the Hvidore Study that the HbA 1c concentrations achieved with intensive therapy varied markedly between centres [9]. It is important to remember that CSII and multiple daily injections are both viable strategies in children and adolescents, and that the final choice of treatment for an individual patient will require a dialogue between the patient, their parents or guardians, and the physician.…”

“…In contrast, in the Hvidore study, HbA 1c increased by a mean of 0.046% (p<0.0001) with each year of age [9]. It is possible that in the present study any effect of age was masked by the influence of treatment duration.…”

“…This approach was used in a previous study from the Pediatric Pump Study Group (PPSG), which collected data retrospectively from 377 children from nine European countries and Israel [16]. This study found high variability, both in agedependent differences in the distribution of basal insulin and in age-independent day-to-day variations in prandial insulin dosing, which was consistent with the variations in glycaemic control that were observed in the Hvidore study [9]. However, measurement of HbA 1c was not standardised, and hence it was not possible to draw any conclusions about the level of glycaemic control achieved with CSII in these patients.…”

“…This, however, is often difficult to achieve in clinical practice because of variable eating patterns and activity and unpredictable absorption of insulin in young children [5][6][7], and difficulties in complying with the demands of regular blood glucose monitoring and multiple daily injections in adolescents [8]. The problems involved in achieving glycaemic control in children are highlighted by data from the Hvidore study [9], which showed that the levels of glycaemic control achieved varied markedly between centres; furthermore, even when treatment was intensified following feedback from betweencentre comparisons of HbA 1c concentrations, glycaemic control was achieved in only a few centres.…”

Type 1 diabetes in the young: the harvest of sorrow goes on

“…When glucose control was studied in 21 paediatric clinics in Europe, Japan and the USA in 1995, the overall mean HbA 1 c was 8.62%. Three years later, and despite strenuous efforts, the mean HbA 1 c remained at 8.67%, with a persistent 2.5% difference between the best-and worst-performing clinics -equivalent to a four-fold gradient in vascular risk [15].…”