Sensor-augmented pump and multiple daily injection therapy in the United States and Canada: post-hoc analysis of a randomized controlled trial

Objective: Effectiveness of advanced technologies for diabetes management may differ depending on national healthcare models or population characteristics. In the setting of a cross-national trial, we aimed to compare efficacy of sensor-augmented pump (SAP) therapy in the United States (US) and Canada.

Methods: In the clinical trial Sensor-Augmented Pump Therapy for A1C Reduction (STAR 3), 329 adults with type 1 diabetes were randomly allocated to either SAP or glargine-based multiple daily injection (MDI) therapy at 26 US sites (n=271) and 4 Canadian sites (n=58). A bootstrap analysis was performed to confirm significant differences in baseline characteristics. For the primary analysis, we compared the baseline to 1-year change in glycated hemoglobin (A1C) between Canadian and US subjects.

Results: At baseline, compared with US subjects, Canadian subjects were more likely to be students (19% vs. 7%, p<0.01) and to consume alcohol (91% vs. 63%, p<0.01). Although Canadian subjects had greater A1C reductions from baseline compared with US subjects (p=0.02), the incremental benefit of SAP was similar in the US (SAP compared with MDI, -0.93%±0.73% vs. -0.31%±0.81%, p<0.001) and Canada (-1.14%±0.72% vs. -0.67%±0.71%, p<0.001). Mean sensor use was significantly higher in Canada than in the US (79% vs. 68% of the time, p<0.001).

Conclusions: Despite differences in baseline characteristics and sensor adherence, SAP efficacy was similar between US and Canadian participants. As long as the intervention is administered with a similar level of expertise as was conducted in the trial, it is likely to be applicable in diverse clinical practice settings.