Determinants of Age at First Exposure to Digital Devices Among Children Aged 2 to 6 Years: Survival Analysis

Background: Digital media exposure is nearly universal by the preschool years. However, little is known about the timing of first exposure to different devices, and the factors associated with earlier exposure. Objective: This study examined age at first exposure to multiple digital devices and investigated sociodemographic, family, and behavioral factors associated with earlier exposure in preschool-aged children. We hypothesized that the timing of exposure would vary according to device-specific family and parental factors. Methods: Cross-sectional data from 892 Portuguese children aged 2 to 6 years were analyzed. Parents reported their children's age at first exposure to television, video game consoles, computers, tablets, and smartphones. Children not yet exposed were treated as censored observations. Kaplan-Meier analyses estimated the median age at first exposure, and Cox proportional hazards models examined associations with child sex, parental education, parental screen time, and the presence of older siblings. Results: Among 892 children, exposure to digital devices was nearly universal (n=889, 99.7%), with television being the most common device. The median age at first exposure to any device was 12 months, with 581 (65.1%) children exposed by this age. Timing of exposure varied substantially across devices, with the earliest exposure observed for television, followed by smartphones and tablets, whereas computers and video game consoles were introduced later. Associations with earlier exposure differed by device. Earlier video game exposure was associated with being male and having older siblings. Parental screen time was statistically associated with earlier exposure to computers and tablets, although the magnitude of these associations was small. Smartphone exposure was associated with higher paternal education. No consistent factors were observed for television or overall device exposure. Conclusions: Digital device exposure begins during infancy and is widespread by the preschool years, but the timing and associated factors differ across devices. These findings suggest that early digital exposure is not a uniform behavior and support the importance of considering device-specific patterns when examining children's early media experiences.