Association Between Excessive Internet Use Time, Internet Addiction, and Physical-Mental Multimorbidity Among Chinese Adolescents: Cross-Sectional Study

Abstract

Background: In contemporary society, the lives of adolescents are profoundly influenced by the internet. While irrational internet use may have an impact on the physical and mental well-being of teenagers, the relationship between excessive internet use and physical-mental multimorbidity in adolescents remains unclear.

Objective: The aim of this study was to examine the relationship between excessive internet use and physical-mental multimorbidity among adolescents in China.

Methods: A total of 5842 students aged 13 to 18 years from Suzhou city in Eastern China were recruited. Four specific physical disorders and a mental disorder were considered to assess the physical-mental multimorbidity, that is, obesity, hypertension, myopia, dental caries, and depressive symptoms. Logistic regression models were used to evaluate the odds ratios (ORs) and 95% CIs between internet use time, internet addiction (IA) behaviors, and physical-mental multimorbidity. Mediation analyses were performed to explore the mediating effect of sleep duration, diet scores, and tobacco or alcohol consumption on the association between excessive internet use and physical-mental multimorbidity.

Results: A total of 973 (16.7%) students exhibited physical-mental multimorbidity. Students with excessive internet use time (≥2 hours per day) were associated with 45% higher odds of physical-mental multimorbidity compared to their peers who reported internet use for <1 hour per day. Among children and adolescents, a significant J-shaped association was observed between internet use time and physical-mental multimorbidity (nonlinear P<.001). Diet score (16.3%) and tobacco or alcohol consumption (12.7%) partially mediated the relationship. Students who met 1 IA behavior (OR 2.44, 95% CI 2.00-2.98) or ≥2 IA behaviors (OR 5.80, 95% CI 4.90-6.86) were associated with higher odds of physical-mental multimorbidity. In the total population, a positive nonlinear correlation was identified between the number of IA behaviors and physical-mental multimorbidity (nonlinear P<.001). Sleep duration (2.3%), dietary scores (6.1%), and tobacco or alcohol consumption (6.2%) partially mediated the association.

Conclusions: Excessive internet use is associated with increased odds of physical-mental multimorbidity among adolescents. Sleep duration, dietary quality, and tobacco or alcohol consumption may partially mediate this relationship. These findings highlight the need for monitoring and promoting healthy internet habits as well as addressing lifestyle factors in order to prevent and control physical-mental multimorbidity among adolescents. This research will also provide references for managing internet use and physical-mental health as well as for future longitudinal studies.

Keywords: adolescent; cross-sectional study; internet use; mediation analysis; physical-mental multimorbidity.

Figure 1

Dose-response association between internet use time and the number of IA behaviors and physical-mental multimorbidity in all students. The dotted line presents the 95% CIs. Models were adjusted for age, sex, grade, the number of family members, BMI, and physical activity. P (nonlinear) was <.001 between internet use time and physical-mental multimorbidity and <.001 between the number of IA behaviors and physical-mental multimorbidity. IA: internet addictive; OR: odds ratio.

Figure 2

Forest plots for internet use time and the number of IA behaviors in subgroups. ORs and 95% CIs for internet use time ≥2 hours per day and for IA behaviors ≥2 are shown for subgroups as defined by baseline participant characteristics. IA: internet addictive; OR: odds ratio.