The association of screen time with problematic smartphone use by educational attainment and household income in Hong Kong Chinese adults: a population-based study

Abstract

Background: Studies have found the association of screen time with problematic smartphone use (PSU), but few investigated potential interaction effects of socioeconomic status. We studied the associations stratified by socioeconomic indicators among Hong Kong Chinese adults. Methods: We analyzed data of 5063 respondents (mean age 48.1 years, SD 18.2; 45.0% men) from a probability-based telephone survey in 2017. PSU was assessed by the Smartphone Addiction Scale-Short Version with higher scores indicating higher risks. Hours per day on the computer, tablet or smartphone were self-reported. We used multivariable regression to examine the associations stratified by educational attainment (3 levels) and monthly household income (2 levels), adjusting for sociodemographic variables. Results: Screen time increased with education and income levels (both P < .001). Each hour longer screen time was associated with greater PSU risks (adjusted beta 0.50; 95% CI 0.37–0.64), but the association was stronger in respondents with lower education (adjusted beta 0.93, 0.59 and 0.33 for ≤ primary, secondary and tertiary education, respectively) and lower income levels (adjusted beta 0.94 and 0.40 for lower and higher income) (both P for interaction < .05). Conclusions: Hong Kong Chinese adults with lower educational attainment and household income were more susceptible to PSU associated with screen time.