Background and aims: Only a few specialised centres in Germany initiated insulin pump therapy before 1990. Initiation of pump therapy involves the participation in a structured treatment and teaching programme (TTP). During the last decade insulin pump therapy has been widely used. The impact of this decentralisation on the quality of care is still unknown. The aim of this trial was both to evaluate the outcome of insulin pump therapy outside specialised centres and to identify features that might be associated with persistently increased HbA1 c levels.
Patients and methods: 250 patients with type 1 diabetes mellitus (age 36.0 +/- 13.1 years; diabetes duration 16.1 +/- 9.9 years), who were on continuous subcutaneous insulin infusion (CSII) therapy during 1999 - 2000, were individually included in the study. Second examination was performed one year after participation in the in-patient TTP for insulin pump therapy. Patients were recruited from 21 member institutions of the Working Group for Structured Diabetes Therapy of the German Diabetes Association. Further details were sought by questionnaire on those patients with persistently increased HbA1c (> 1.7 fold of mean normal range.)
Results: One year after participation in the TTP for CSII relative HbA1c (original value/mean normal of the local method [Müller et al., 1999]) decreased from 1.51 (0.9 - 3.2) to 1.44 (0.9 - 3.6) (p < 0.0001), severe hypoglycaemia from 0.46 to 0.12/patient/year (p < 0.001), severe ketoacidosis from 0.08 to 0.05/patients/year (p = 0.003) and hospitalisation from 5.2 to 3.1 days/patient/year (p = 0.002). In 43/207 (17%) the incidence of severe hypoglycaemia was unchanged (before 0.12 and after TTP 0.14/patients/year), there was slight increase in severe ketoacidosis (before 0.15; after TTP 0.23/patients/year) and hospitalisation days were unchanged (before 4.5; after TTP 4.4 days/patients/year). The following factors were associated with adverse outcomes: psychological problems including eating disorders and alcohol abuse (28%), lack of interest in self-management (28%) and social problems (11%). In 28% there was no follow-up treatment by diabetologists specialised in pump therapy.
Conclusion: The benefits of insulin pump therapy are improvement of HbA1c, reduction of hypoglycaemia, ketoacidosis and hospitalisation days as well as improved flexibility. It is possible to draw up a list of clinical criteria and service requirements, which are likely to reduce failures.