Smartphone use health outcomes in children and adolescents: A systematic review of behavioral, developmental, and environmental risk pathways

Table 1 PICO framework for the systematic review

Component	Description	Operational definition in this review
Population (P)	Children and adolescents	Individuals aged 0-18 years. Studies including mixed populations were eligible only if pediatric data were reported separately. Subgroup analyses planned for early childhood (0-5 years), school-age children (6-12 years), and adolescents (13-18 years)
Exposure (I/E)	Mobile phone use and exposure	Use of smartphones or cellular phones, including: (1) Duration and frequency of use; (2) Voice calls and messaging; (3) Internet browsing; (4) Social media engagement; (5) Mobile gaming; (6) Night-time use; and (7) RF-EMF exposure attributable to mobile phones
Comparator (C)	Lower or no exposure	(1) Non-users vs users; (2) Low vs high usage groups; (3) Short vs prolonged exposure; (4) Baseline vs follow-up (longitudinal studies); and (5) Different exposure intensities (e.g., hours/day, nighttime use)
Primary outcomes (O1)	Core health outcomes	(1) Sleep disturbances (duration, quality, latency); (2) Mental health outcomes (anxiety, depression, emotional symptoms); (3) Attention and executive function; and (4) Neurodevelopmental outcomes
Secondary outcomes (O2)	Additional health and behavioral outcomes	(1) Visual complaints (digital eye strain, myopia); (2) Musculoskeletal symptoms; (3) Physical activity levels and obesity; (4) Problematic smartphone use/addiction behaviors; (5) Academic performance; and (6) Biological or health effects related to RF-EMF exposure
Study designs	Eligible study types	Randomized controlled trials, cohort studies, case-control studies, and cross-sectional studies
Setting	Geographic scope	No geographic restriction; studies from all regions included

RF-EMF: Radiofrequency electromagnetic field.