Abstract
PURPOSE: The efficacy of sleep extension therapy using a remote support system (SET-R) was investigated in university students with increased social jetlag (SJL). METHODS: For this two-arm parallel randomized controlled trial, we recruited Japanese university students with SJL ≥ 60 min. The SET-R provided an individualized sleep schedule for gradual sleep extension using email and sleep hygiene education, stimulus control therapy, and progressive muscle relaxation as web content. The control group was sent an email that encouraged them to record their sleep. The duration of the intervention program was two weeks. The primary outcome was the mean change in SJL two weeks later, assessed using the Munich ChronoType Questionnaire (MCTQ). The other outcomes included Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale (ESS), Insomnia Severity Index, Patient Health Questionnaire-9 (PHQ-9), and sleep quiz. A follow-up survey was conducted 6 months after the intervention. RESULTS: Of 54 students, 26 were assigned to an intervention group and 28 to a control group. The difference in the mean change in SJL between the two groups (n = 26, n = 27) at two weeks was statistically significant (27.7 min, P = 0.048). The scores for the ESS, PHQ-9, and sleep quiz were improved in the intervention group relative to the control group. At the 6-month follow-up point, the difference in the mean change in SJL between the two groups (n = 22, n = 27) was not statistically significant, but scores for the PHQ-9, and sleep quiz remained significant. CONCLUSIONS: This study demonstrated the efficacy of the SET-R among university students with increased SJL. TRIAL REGISTRATION: The study was registered with the UMIN Clinical Trials Registry (UMIN000042634, 2021/02/01).