Association between trajectories of problematic mobile phone use and chronotype among Chinese college students

Aims: This study aimed to describe the prevalence of problematic mobile phone use (PMPU) and chronotype among Chinese college students, estimate PMPU development trajectories, and further examine the effect of PMPU trajectories on chronotype. Design: In a stratified cluster sampling design, PMPU and chronotype were evaluated in 999 college students from two universities in a 2-year prospective investigation from April 2019 to April 2021, and an investigation was conducted every six months (time 1 - time 5, T1 - T5). Participants: N = 999 college students (mean age at T1: 18.8 years (SD = 1.2), 37.7% male) took part in the study. Measurements: The Self-rating Questionnaire for Adolescent Problematic Mobile Phone Use (SQAPMPU) and the Pittsburgh Sleep Quality Index (PSQI) were used to assess the PMPU and sleep quality of college students at each time point. The Morning and Evening Questionnaire (MEQ) was adopted to investigate the chronotype of college students at T5. Findings: The prevalence of PMPU at T1 - T5 was 24.3%, 27.3%, 35.1%, 31.2% and 31.9%, respectively. The prevalence rates of morning types (M-types), neutral types (N-types), and evening types (E-types) were 19.1%, 70.8%, and 10.1%, respectively. Using latent growth mixture modelling, we identified three trajectories of PMPU: low-level (49.5%), moderate-level (38.6%), and high-level score trajectories (11.9%). Multivariate logistic regression analysis results showed that a trajectory with a high score was positively associated with E-types (P < 0.05). After stratification by gender, a high-level score trajectory was positively associated with E-types only among female college students (P < 0.05). There were sex differences in the association between trajectories of PMPU and chronotype. Conclusion: Long-term symptoms of PMPU may be a potential risk factor for circadian rhythm disturbance among college students, and this effect was significantly different between genders.