Social Support and Daytime Sleepiness Among Chinese Medical Students: Mediating Roles of Loneliness and Problematic Smartphone Use

BACKGROUND: Sleep problems have become a serious threat to public health worldwide. Daytime sleepiness is an important indicator of many sleep problems, which have a significant impact on academic performance, physical and mental health, and wellbeing among medical students. We aimed to explore the factors associated with daytime sleepiness among medical students. METHODS: We conducted a cross-sectional survey of 466 medical students recruited via convenience sampling. Self-rated psychometric scales, including the Social Support Rate Scale, the Epworth Sleepiness Scale, the Chinese version of the UCLA loneliness scale, and the Mobile Phone Addiction Index (MPAI), were utilized to evaluate social support, daytime sleepiness, loneliness, and problematic smartphone use. A sequential mediation model was constructed with daytime sleepiness as the dependent variable, social support as the independent variable, and loneliness and problematic smartphone use as mediating variables. Age, gender, and grade were taken as covariates. RESULTS: Social support among medical students was negatively associated with loneliness, problematic smartphone use, and daytime sleepiness (p < 0.01). A sequential mediation analysis showed that loneliness (the first mediator) and problematic smartphone use (the second mediator) sequentially mediated the path from social support to daytime sleepiness among medical students (β = −0.008; 95% CI = −0.016, −0.002). Moreover, there were also significant mediating roles observed in the relationship between social support and daytime sleepiness via loneliness only (β = −0.037; 95% CI = −0.062, −0.015) and problematic smartphone use only (β = −0.022; 95% CI = −0.041, −0.008). CONCLUSION: Social support, loneliness, and problematic smartphone use among medical students influenced their daytime sleepiness. Interventions targeting medical student loneliness and problematic smartphone use behaviors might attenuate the effects from low levels of social support and further improve daytime sleepiness.