The SWITCH Study (Sensing With Insulin pump Therapy to Control HbA_1c): Design and Methods of a Randomized Controlled Crossover Trial on Sensor-Augmented Insulin Pump Efficacy in Type 1 Diabetes Suboptimally Controlled with Pump Therapy

Abstract

Background: Studies investigating the effect of real-time continuous glucose monitoring (CGM) combined with pump therapy on glycemic outcomes in type 1 diabetes are increasing. Pump therapy is well established as a ''gold standard'' for insulin delivery, offering improvements over multiple daily insulin injections. However, there is still a proportion of subjects using continuous subcutaneous insulin infusion in whom goals for metabolic control are far from achieved or benefits of this type of insulin therapy are transient. The SWITCH (Sensing With Insulin pump Therapy to Control HbA 1c [hemoglobin A1c]) study is a multicenter, randomized, controlled, crossover study to evaluate if adding CGM to experienced pump patients with suboptimal metabolic control will provide additional insight enabling clinical and therapeutic benefit. Methods: Subjects meeting the inclusion criteria were randomized to Sensor On or Sensor Off arms for 6 months, after a 1-month run-in period. Following a 4-month washout period, the subjects crossed over to the other study arm for 6 months. The primary end point was the between arm difference in HbA 1c levels. Among others, additional end points include time spent in different glycemic ranges, percentage of patients with HbA 1c <7%, number of hypoglycemic events, glucose variability parameters, safety outcomes, treatment satisfaction, and quality of life. Results: Recruitment occurred between January 2008 and February 2009. A total of 153 patients were randomized. Study completion is anticipated in July 2010. Conclusions: The results will establish if adding CGM to existing, capable, insulin pump users can enable better metabolic control.

The use and efficacy of continuous glucose monitoring in type 1 diabetes treated with insulin pump therapy: a randomised controlled trial

“…Adult participants were aged 19−70 years; paediatric participants were aged 6−18 years. In addition, eligible participants had been using CSII with rapid-acting insulin analogues for more than 6 months, were naive to CGM and had successfully completed a five-question multiple choice test concerning pump therapy and general understanding of diabetes [15]. Exclusion criteria included ≥3 incidents of severe hypoglycaemia in the last 12 months, a history of hypoglycaemia unawareness (i.e.…”

Impact of continuous glucose monitoring on quality of life, treatment satisfaction, and use of medical care resources: analyses from the SWITCH study

“…Details of the SWITCH study have been presented in full elsewhere [12]. In brief, the study was a randomized, controlled, crossover study involving patients aged between 6 and 70 years with type 1 diabetes of more than 1 year and an HbA 1c level between 7.5 and 9.5 % (59–80 mmol/mol).…”

“…The per-protocol population (PP) included patients compliant with the protocol who used the sensor at least 70 % of the required time. Missing data within each treatment period were replaced according to the last observation carried forward (LOCF) principle, and possible carryover effects were minimized using a 4-month washout period [12]. HbA 1c levels in the sensor-On and sensor-Off treatment periods were compared by means of an analysis of covariance (ANCOVA) model with adjustment for period effect and subject as random effect.…”

Real time continuous glucose monitoring: how does it work in real life?

“…11 The recently completed SWITCH study will hopefully answer the latter question soon. 12 Only one study was designed to investigate which patients would benefit most from this new technique. 13 The only baseline factors found to be associated with greater CGM use in month 6 were age ≥25 years and more frequent self-reported pre-study blood glucose measurements per day.…”