The current manuscript presents results from a descriptive study of sleep in adolescents and young adults with and without type 1 diabetes. Strengths of the study include the inclusion of a control group, and the use of actigraphy as well as a subjective measure of sleep quality. However, the lack of details regarding sample recruitment and differences between the two samples require more discussion. Suggestions for edits are below:
Introduction:
1. The authors do a nice job of reviewing the relevant literature. Greater attention to developmental issues would further strengthen the introduction and justify the age range included in this study. For example, we would expect quite different bedtimes and sleep duration among early adolescents (age 13-14) as compared to young adults (age 18-20).
Method:
2. It is not clear how representative these samples were. What was the participation rate for each of the studies? Were there differences in demographic or clinical characteristics between the people who did and did not participate in each of the studies? How burdensome was the study for participants (i.e., would adolescents and young adults be less willing to participate in one or the other based on the time commitment and/or compensation?)
3. How were missing data handled in analyses?
4. What was the reliability of the PSQI total score and individual scales? Are the subscales considered reliable and valid for this age group? If not, the focus of the results should be on the global score. This would also reduce the number of comparisons.
Results:
4. For the sample with type 1 diabetes, it would be useful to report the association between HbA1c and the sleep variables.
Discussion:
6. The language in the discussion needs to be tempered to reflect that, once adjustments were made for demographic factors, there were no differences between groups in the objective sleep characteristics.
7. I would like to see greater discussion of why the perceived sleep quality was poorer among young people with type 1 diabetes, but no significant differences in objective sleep were observed. What are the implications for clinical practice and future research?
8. While the inclusion of a control group is a strength of the study, the fact that it was not matched on age, race/ethnicity, or socioeconomic status is a limitation. These differences may explain the lack of findings in the final models.
9. While age was adjusted in the models, as noted above, the age range of participants encompasses early adolescents through young adults, which may also limit the ability to detect effects that are specific to a developmental stage.
Minor Note: The title uses the term “youth” but “adolescents and young adults” may be more appropriate, given the inclusion of adult participants, ages 18-20.

The authors were generally very responsive to my comments. However, I would like to see greater attention to one point: the validity of the use of subscales of the PSQI in this population. The authors note in their response the subscale correlations with the global scale, but I am more concerned about the internal consistency of the subscales or component scores. The Raniti et al., 2018 paper cited indicates that a single factor model is most appropriate in adolescents, so I would recommend that the subscale analyses be omitted, with the focus on the valid and reliable global score. This would also reduce the number of comparisons.