Characteristics of Sleep Pattern among Korean College Students / 수면정신생리

ABSTRACT

INTRODUNTION: The objective of the present study was to investigate bedtime, rise time and time-in-bed of Korean college students, separately on weekday and on weekend and to compare them. In addition, this study also aimed to evaluate the influence of gender, age and grade on the above sleep parmeters in Korean college students. METHODS: Information regarding bedtime and rise time, separately on weekday and on weekend, of Korean college students were obtained by self-administered questionnaire. Questionnaires of 1,825 students (1,416 females and 409 males, age 18-30 ; mean age 21.1+/-2.2) were used for statistical analyses. RESULTS: Korean college students retired to bed 50 minutes later (00 : 49 on weekday ; 01 : 40 on weekend ; t=39.67, p<0.001), rose 1 hour 58 minutes later (07 : 52 on weekday ; 09 : 50 on weekend ; t=39.46, p<0.001), and slept 1 hour 8 minutes longer (t=13.33, p<0.001) on weekend. Compared to male students, female students had earlier rise time (t=8.96, p<0.01 ; t=3.89, p<0.01) and earlier bedtime both on weekday and weekend (t=7.10, p<0.01; t=6.04, p<0.01), and shorter time-in-bed on weekday (t=1.99, p<0.01). In addition, rise time delay and time-in-bed increase on weekend were more prominent in female students than in male students (t=3.41, p<0.01 ; t=3.68, p<0.01). Grade was correlated with bedtime and rise time on weekday (beta=0.1022, p<0.01 ; beta=0.1009, p<0.01), bedtime and time-in-bed on weekend (beta=0.1096, p<0.01 ; beta=-0.0990, p<0.01), and differences between weekday and weekend of the rise time and the time-in-bed (beta=-0.0906, p<0.01 ; beta=-0.1115, p=0.02). CONCLUSIONS: In this study, Korean college students had earlier bedtime/rise time and shorter time-in-bed on weekday than on weekend. These findings suggest that weekday sleep-wake schedule of Korean college students may be advanced relative to their biological sleep-wake cycle and that this discrepancy may be associated with weekday sleep deprivation. In addition, differences of sleep patterns between weekday and weekend were more prominent in female students and students with lower grade. Therefore, discrepancy between weekday sleep-wake schedule and biological sleep-wake cycle, as well as weekday sleep deprivation, might be more serious in female or lower-grade students.