Does Sedentary Behavior Context Matter for Problematic Smartphone Use? Associations with Screen-Based,...

Background: This study assessed the associations of screen-based, non-screen-based, and mixed sedentary behavior (SB) with problematic smartphone use (PSU) in adults, and explored whether statistically reallocating screen-based SB to non-screen-based or mixed SB would be associated with lower PSU. Methods: This secondary analysis of a web-based cross-sectional study included 1037 adults (average age = 28.9 years; 52.9% women). The culturally adapted Arabic version of the Sedentary Behavior Questionnaire estimated SB. The Arabic version of the Smartphone Addiction Scale measured PSU. Adjusted partition regression and isotemporal substitution models evaluated the study's objectives. Results: Higher screen-based SB was associated with higher PSU (B ranged between 1.725 and 5.891 points; p < 0.05 for all). Non-screen-based and mixed SB were associated with lower PSU in specific analyses among women (B ranged between -1.200 and -1.886 points; p < 0.05 for all), whereas no statistically significant associations were observed among men (p > 0.05). Statistically reallocating time spent in screen-based SB to non-screen-based or mixed SB was associated with lower PSU in several analyses (B ranged between -2.299 and -7.777 points; p < 0.05 for all). For weekdays and weekends, statistically significant associations were observed for selected SB categories, with fewer statistically significant associations observed in the weekend analyses. Conclusions: These findings suggest that higher screen-based SB was associated with higher PSU, whereas associations of non-screen-based and mixed SB with PSU were less consistent. Statistically reallocating reported screen-based SB to non-screen-based or mixed SB may be associated with lower PSU. These findings do not establish causal effects or actual behavioral changes, and further prospective and experimental research is required.