The Effect of Sleep Quality on Students' Academic Achievement [Response to Letter].

Dear editor

I read the letter from the students of the University of Manchester entitled “Medical Students’ Perspective on the Effect of Sleep Quality on Academic Performance.” I thank them for their attention and I wish that our students grew up with critical thinking.

Turning to their views on the article by me and my colleagues,1 I want to clarify that several studies are done on the relationship between sleep quality and academic achievement, including systematic reviews and meta-analysis.2,3 In the studies, correlation have been studied from different aspects, taking into account confounding variables such as age,4 although there is still no definite answer as to whether these two variables are related or not.5 In the present study,1 the authors intended to respond to these controversy views by using a type of sampling in qualitative research named purposeful sampling with maximum variation. We assumed that if sleep quality was the main variable and predictor of academic success, students (regardless of field of study, semester, and gender) with better academic performance (based on grade point average) should have lower sleep quality scores (better sleep quality). Conversely, students with lower academic performance have higher sleep quality scores while no correlation was found. However, for better commentary, a more accurate answer can be obtained by using interventional and longitudinal studies with appropriate sample size and eliminating confounding variables. However, academic achievement and sleep quality are both composite variables and several factors are involved in their formation as well as their relationship, so any claim must be taking into account all those variables.

Finally, this study has no other claim than what is concluded in conclusion section, and also longitudinal studies are recommended. This study intended to answer the question of the relationship between sleep quality and academic achievement and intended to shed light on this ambiguity from another aspect.