Evaluation of psychometric properties of sleep quality questionnaire among medical students of Guilan University of Medical Sciences

Abstract

Abstract Background Since evaluating sleep quality among students is of great importance and is one of the challenges facing the health field regarding this group, we were determined to conduct this study to evaluate the psychometric properties of the Sleep Quality Questionnaire (SQQ) among the medical students at the Guilan University of Medical Sciences. Methods This research was conducted as a cross-sectional study. In the procedure, a random group of medical students at Guilan University of Medical Sciences were provided with questionnaires and the study’s pre-prepared checklist and were asked to answer them accurately. The questionnaires used in this study include the Sleep Quality Questionnaire (SQQ), and the Pittsburgh Sleep Quality Index (PSQI). After collecting the entries, all the data were subjected to a statistical analysis using the SPSS software. Results In this study, 249 medical students with an average age of 23.88 ± 2.46 were evaluated, of which 140 (56.2%) were female and the rest were male. According to the results, the average sleep quality for SQQ was 19.31 ± 8.06, and the Pittsburgh Sleep Quality Index (PSQI) was 7.95 ± 3.76. Based on the results obtained from the exploratory analysis, it was determined that no high overlap exists between the two evaluated factors in the sleep quality questionnaires, confirming their divergent validity. In evaluating the convergent validity, the correlation between the SQQ and PSQI questionnaires was reported as 0.642, which was significant (p < 0.001). Cronbach’s alpha for the SQQ questionnaire was equivalent to 0.882, which is verified since the minimum value is 0.70. Also, utilizing the test-retest method, the reliability was found to be 0.74, which is acceptable according to the minimum value of 0.70. SQQ scores had a direct and meaningful relationship with age (r = 0.185, p = 0.003). Based on the pairwise comparison, there was a significant difference in SQQ scores between the students in different stages and the duration of sleep. Conclusion The current study’s findings indicate that the SQQ questionnaire possesses adequate validity and reliability, which could be utilized to evaluate sleep quality in domestic studies.