Dose-response analysis of smartphone usage and self-reported sleep quality: a systematic review and meta-analysis of observational studies

Study Objectives: Several studies have recently reported on the association between smartphone usage and self-reported sleep quality. However, no systematic review or meta-analysis has yet been performed. We aimed to analyze the association between smartphone usage time and self-reported sleep quality. Methods: We searched for articles published up to January 13, 2022, using the Embase and Medline databases. All observational studies were eligible for inclusion. The Newcastle-Ottawa scale was used to evaluate the risk of bias within studies. We used restricted cubic spline analysis to perform a dose-response analysis. Results: Seventeen studies with a total of 36,485 participants were included. The pooled odds ratio was 2.28 (confidence interval [CI]: 1.81-2.89; P < .001) and heterogeneity was 80%. In the dose-response analysis conducted on 5 studies, the regression coefficient between daily smartphone usage time (hours/day) and poor sleep quality was 1.042 (1.027-1.058), which confirmed a significantly positive association. Conclusions: Smartphone overuse was closely associated with poor self-reported sleep quality, sleep deprivation, and sleep latency prolongation. Further studies using a more structured method and high-quality evidence (cohort or case-control) should be conducted. Systematic Review Registration: CRD42022303371.