Lecture start time and sleep characteristics: Analysis of daily diaries of undergraduate students from the LoST-Sleep project.

ABSTRACT

OBJECTIVES: Emerging evidence shows that later high school start times are associated with increased sleep duration; however, little is known if this extends to the university setting. This study investigated associations of first lecture start times with sleep characteristics among university students. DESIGN: Daily diaries. SETTING: Lincoln, UK. PARTICIPANTS: One hundred and fifty-five undergraduate students completed 7-night sleep diaries MEASUREMENTS Of the plausible lecture-day diaries (Monday-to-Friday, expected N = 755 days), 567 days were lecture days (M = 3.8 lecture-days per student, SD = 1.1). The Consensus Sleep Diary was used to collect sleep characteristics. Two-level multilevel mixed effect generalized linear models were employed in the analyses. RESULTS: Seventy-five percent of first lectures occurred before noon. Students reported short sleep (M = 7.0 hours, SD = 1.9) and fewer reported highest levels of sleep quality (42.8%) and restfulness (24.8%) when first lectures started at 0900 or 0930 compared to 1000 or later. Every hour delay of first lecture start time was associated with 15.1 (95% confidence interval [CI] 9.5; 20.7) minutes increase in sleep duration and higher odds of reporting the highest levels of sleep quality and restfulness. Focusing on attended lectures starting before noon, hourly delay of first lecture start time was associated with 37.4 (95% CI 22.0; 52.8) minutes increased sleep duration. Bedtime, sleep time, and sleep onset latency were not significantly associated with first lecture start times. CONCLUSION: This study found that undergraduate students had longer sleep and healthier sleep quality when university first lectures started later. The earliest lecture start time that afforded sufficient sleep duration for students was 1000.