Association between Recreational Screen Time and Sleep Quality among Adolescents during the Third Wave of the COVID-19 Pandemic in Canada

Round 1

Reviewer 1 Report

The authors present a body of data interesting for the audience. There are some concerns that prevent me to accept it as it stands. 

Introduction, last part. 

-The manipulation and the instruments adopted are neither  mentioned nor scientifically justified.

-Expectations have to be given.  

Materials and Methods

-The reader may wonder what the results of the preliminary study were. I suggest adding this information.

-Cronbach's alfa and other details should be given for the questionnaires.

-Sample size. Please, justify the number of participatns involved.

-Table 1 caption is unclear and partial with respect to data reported in the table.

-Consider that Fig 1 is substantially superimposed on table 3.

Finally, the authors honestly stated all the limitations of the study, and this allows the scientific audience to better assess whether or not this study should be considered. 

Author Response

We thank the editor and Reviewer #1 for their careful reading and constructive criticism on the original submission. We have made changes to the manuscript on the basis of the comments, and believe that the revised manuscript has improved as a result of these changes.

Comment 1: The authors present a body of data interesting for the audience. There are some concerns that prevent me to accept it as it stands.

Response 1: We thank the reviewer for finding our data interesting and for providing us suggestions on how to improve our paper.

Comment 2: Introduction, last part: The manipulation and the instruments adopted are neither mentioned nor scientifically justified.

Response 2: This study does not include any manipulations. It did not adopt an experimental design; it was a cross-sectional survey on adolescents’ recreational screen time and sleep quality. The instruments adopted are mentioned in the Materials and Methods section (see 1^st and 2^nd paragraphs on page 4). We also justify the use of the Screen Time-Based Sedentary Behavior Questionnaire and the short version of the Adolescent Sleep-Wake Scale by the fact that both instruments were validated in adolescent samples. This information already appears in the manuscript (see 1^st and 2^nd paragraphs on page 4).

Comment 3: Introduction, last part: Expectations have to be given.

Response 3: In the last paragraph of the introduction, we already mention that we expect that the increases in recreational screen time during the peak of the COVID-19 pandemic will be associated with declines in sleep quality among adolescents (see page 3).

Comment 4: Materials and Methods: The reader may wonder what the results of the preliminary study were. I suggest adding this information.

Response 4: We are not sure what the reviewer is referring to. If the reviewer is referring to the larger study on the psychosocial correlates of recreational screen time based on the Reasoned Action Approach, those results are not yet published. If the reviewer is referring to the two-week test-retest study conducted prior to the main study, those results are already reported in the present article in a separate paragraph (see section 3.1 Test-Retest Study on page 5).

Comment 5: Materials and Methods: Cronbach's alfa and other details should be given for the questionnaires.

Response 5: We added the κ-values for the test-retest reliability of the Screen Time-Based Sedentary Behavior Questionnaire and also specified that it was validated using objectively measured sedentary time among adolescents (12-18 years) (see top of page 4). We added that the short version of the Adolescent Sleep-Wake Scale had acceptable internal consistency with all Cronbach alpha coefficients > 0.70 in two previous studies among adolescents (12-18 years) (see middle of page 4).

Comment 6: Materials and Methods: Sample size. Please, justify the number of participants involved.

Response 6: We have computed a sample size calculation a-priori for our larger study on the psychosocial correlates of recreational screen time. This sample size calculation was not reported in the present manuscript as it was not calculated for the objective of this study. We did however add a sample size calculation specific to the objective of the study reported in the present article (see top of page 5).

Comment 7: Materials and Methods: Table 1 caption is unclear and partial with respect to data reported in the table.

Response 7: Table 1 does not contain a footnote as we find its content is fairly self-explanatory. It reports the age, biological sex, gender and school level of the adolescents included in our study.

Comment 8: Materials and Methods: Consider that Fig 1 is substantially superimposed on table 3.

Response 8: We agree with the reviewer that it looks like Figure 1 is superimposed on Table 3. This may be because the top line of Figure 1 is missing in the article. In the Figure 1 supplied during the submission of the article, it had a line at the top of the figure. We have re-submitted Figure 1 along with the revised version of our article.

Comment 9: Finally, the authors honestly stated all the limitations of the study, and this allows the scientific audience to better assess whether or not this study should be considered.

Response 9: We are glad the reviewer finds that we stated all the limitations of our study.

Author Response File: Author Response.pdf

Reviewer 2 Report

This is a thorough, well-written paper.

Under limitations (in Discussion), I agree that timing of screen time (especially whether right before bedtime) is very important to ask and I am surprised that this was not asked.

With the prevalence of blue light blocking glasses and screens, it would also be of interest to ask about whether these are being used.  Blue light is what is thought to disrupt sleep.

Another limitation is that the data is based on retrospective "estimates" of screen time rather than objective measures.  It is possible that the estimates are systematically off.

Author Response

We thank the editor and reviewer #2 for their careful reading and constructive criticism on the original submission. We have made changes to the manuscript on the basis of the comments, and believe that the revised manuscript has improved as a result of these changes.

Comment 1: This is a thorough, well-written paper.

Response 1: We thank the reviewer for this kind comment.

Comment 2: Under limitations (in Discussion), I agree that timing of screen time (especially whether right before bedtime) is very important to ask and I am surprised that this was not asked.

Response 2: We agree with the reviewer that when looking at whether recreational screen time can have an impact on adolescents’ sleep quality, it is important to assess whether this occurs before bedtime (e.g., within 1 hour of bedtime). The validated instrument used to measure recreational screen time in our study did not have any items on when this occurs in a day. There is also data suggesting that daytime (not just bedtime) screen time can negatively affect adolescents’ sleep (see Hysing et al., 2015. Sleep and use of electronic devices in adolescence: Results from a large population-based study. BMJ open).

Comment 3: With the prevalence of blue light blocking glasses and screens, it would also be of interest to ask about whether these are being used.  Blue light is what is thought to disrupt sleep.

Response 3: We agree that future studies may want to ask adolescents if they are using blue light-blocking glasses or the blue light filer mode on their electronic devices in the evening. We added that there is also data suggesting that the use of blue light-blocking glasses can mitigate the impact of evening recreational screen time on adolescents’ sleep and added a scientific reference supporting this claim. We also added that future studies may want to document if adolescents are using those glasses or the blue light filter mode on their electronic devices in the evening (see top of page 11). We thank the reviewer for this suggestion.

Comment 4: Another limitation is that the data is based on retrospective "estimates" of screen time rather than objective measures.  It is possible that the estimates are systematically off.

Response 4: We agree with the reviewer. We added in the strengths and limitations section that ideally, both objective and self-reported measures of adolescents’ recreational screen time and sleep quality should be used to overcome limitations associated with both types of measure (e.g., reactivity for objective measures and memory bias for self-reported measures) and added a scientific reference to support this claim (see top of page 11).