Thank you for asking me to review this paper about treatment satsifcation with iGlarLixi in suboptimally controlled patients with type 2 diabetes.

Whilst treatment satisfaction is clearly an important measure and has links with concordance and therefore suggests the potential to improve longer-term outcomes, this study fails to make a strong case for the significance of these findings.

Positives:
The paper is well written and clearly articulates the research undertaken.

The inclusive nature of this study - ensuring accurate representation of the American population living with Type 2 diabetes. This is rarely seen and lends an important real-world lens to this study.

Concners / Queries:

1. As the original study was single-arm, this means the impact and significance of this paper is limited without a comparison group. The inability to infer any cause and effect is a huge challenge.

How do we know that ANY change of treatment would not have led to the same improvements in treatment satisfaction? How do we know that simply being part of a research study led to the improvements?

1. Adding a qualitative element to this paper would have given greater depth of understanding to the potential improvements in treatment satisfaction.

2. Describing the association as weak but a positive correlation without stating clearly that several of the confidence intervals reported cross zero and therefore lack statistical significance.

3. I am not a statistician but I would imagine there are some rather more sophisticated ways that this data could have been analysed to understand the correlation? For exmaple, to look at the level of improvement in treatment satsifcation alongside the degree of improvement in TIR - using for example regression analysis.

4. What does this paper mean to practicing clinicians and patients? This needs to be more clearly stated.