LAUSR

Bedtime procrastination occurs when individuals go to bed later than they intended despite knowing that there may be negative consequences. The prevalence, drivers, and consequences of bedtime procrastination on daily sleep behavior are poorly understood. In university students, (1) we measured the frequencies and reasons for going to bed later than intended, and (2) we tested the hypothesis that bedtime procrastination results in shorter sleep on school nights but not non-school nights. University students living in a residential college (n=109) completed daily sleep diaries for 2 weeks during their school semester. Each morning, students indicated if they went to bed later than they intended and the associated reasons. Sleep parameters included bedtime, wake-up time, and nocturnal time in bed for sleep. Simple effect sizes were used to compare mean differences in sleep behavior on nights with versus without bedtime procrastination. Students went to bed later than they intended on approximately half of all nights, irrespective of whether they had school the next day (school nights, 56.6%; non-school nights, 51.6%). On school and non-school nights with bedtime procrastination, time in bed was shorter by about 45 min (school nights: mean difference=-0.74h, 95% CI= -0.97h to -0.53h; non-school nights: mean difference=-0.79h, 95% CI=-1.01h to -0.58h). The most common reason for bedtime procrastination was “lost track of time” (34.9%), which was reported nearly twice as often compared with “wanted some me time” (19.5%), “wasn’t tired yet” (16.7%), “engaging in social leisure activities in person” (15.2%), and “engaging in social leisure activities online” (13.6%). The largest decrease in time in bed was observed when bedtime procrastination occurred due to in-person social activities (mean difference=-1.23h, 95% CI=-1.49h to -0.97h). University students living in a residential college frequently engaged in bedtime procrastination on school and non-school nights, resulting in shorter nocturnal sleep opportunities. Losing track of time was the most common reason, suggesting that interventions for improving sleep in these students should emphasize self-regulation and time management skills. Our findings also suggest a strong social component of bedtime procrastination. Ministry of Education, Singapore (MOE2019-T2-074)