What Is The Ideal Bedtime? Data From A Community Sample

Introduction: Advancing bedtime can decrease sleep efficiency, and the delay of bedtime may result in insufficient sleep. In pursuit of an empirically supported, real-­‐world bedtime recommendation, the present study examined community-­‐level data on typical bedtime as it relates to sleep problems. Methods: Data from our SHADES study were used for the analysis, consisting of N=998 adults age 22-­‐60 in Philadelphia. Typical bedtime was assessed and compared to insomnia (ISI), total sleep time, sleep latency, wake after sleep onset, sleepiness (ESS), depression (PHQ9), and anxiety (GAD7). Results were adjusted for age, sex, race/ethnicity, education, and BMI. Results: Compared to 11pm-­‐midnight, higher ISI scores were seen for 1-­‐2am (B=2.65,95%CI[1.36,3.94],p<0.0005), and ≥2am (B=5.79,95%CI[4.50,7.08],p<0.0005). Longer sleep latency was reported by those going to bed ≤8pm (B=14.38,p=0.03), 1-­‐2am (B=8.48,p=0.01), and ≥2am (B=26.88,p<0.0005). Longer WASO was seen for ≤8pm (B=20.76,p=0.04) and ≥2am (B=20.94,p<0.0005). Higher ESS was seen for ≥2am (B=2.27,p<0.0005). Higher PHQ9 was seen for ≤8pm (B=3.19,p=0.02), 1-­‐2am (B=2.43,p<0.0005), and ≥2am (B=4.47,p<0.0005) and lower PHQ9 was seen for 10-­‐11pm (B=-­‐1.39,p=0.01). Higher GAD7 was seen for 1-­‐2am (B=1.64,p=0.009) and ≥2am (B=2.80,p<0.0005). Lowess plots of continuous values show that the minimum value for ISI and other outcomes is at 11pm. Conclusion: Bedtimes of 8pm-­‐1am have fewer problems than bedtimes outside of this window. Bedtimes close to 11pm report the least amount of mental health, sleep, and functioning problems. Work examining modifying bedtimes to promote improvements in these variables is needed