A Response to: Letter to the Editor with Regard to the Cost-Effectiveness of an Advanced Hybrid Closed-Loop System in People with Type 1 Diabetes: A Health Economic Analysis in Sweden

Abstract

We would like to thank Levrat-Guillen and Ghazi for their interest in our recent analysis relating to the cost-effectiveness of advanced hybrid closed-loop (AHCL) insulin delivery relative to intermittently scanned continuous glucose monitoring (isCGM) in combination with multiple daily injections (MDI) or continuous subcutaneous insulin infusion (CSII) in people with type 1 diabetes (T1D) [1].Levrat-Guillen and Ghazi have expressed concern over several aspects of the analysis.In an attempt to alleviate these concerns, the issues raised are addressed in a point-by-point fashion below.In the absence of head-to-head comparisons of AHCL versus isCGM, Levrat-Guillen and Ghazi expressed concern over the clinical input data used to inform the analysis.For the isCGM arm, the HbA1c treatment effect was sourced from the real-world FUTURE study published by Charleer et al. [2].Whilst several other potential data sources were available, the FUTURE study was chosen owing to the robust nature and design of the study (e.g., the study was conducted in specialist diabetes centers, with a large number of patients and long duration of follow-up) and a baseline HbA1c value that closely matched the levels observed in the study published by Collyns et al. [3], which was used to inform the AHCL arm.Levrat-Guillen and Ghazi mentioned three sources specifically (Gilbert et al. [4], Evans et al. [5], and Rose et al.[6]) but these studies were not considered for several reasons.The study published by Gilbert et al. [4] was considered inappropriate as the authors assessed the effectiveness of real-time CGM (rtCGM) rather than isCGM; utilization of this study would therefore require the assumption that isCGM and rtCGM are equivalent and evidence from a recent head-to-head study has suggested that this is not the case [7].The metaanalysis by Evans et al. [5] reported a mean HbA1c reduction of 0.56% with isCGM; however, this was based on a large number of studies with baseline HbA1c values ranging from 6.79% to 10.28%.Finally, in the German observational study by Rose et al. [6], patients had a mean