Background/aim Mobile phone use in children and adolescents has steadily increased over the past decade, and public health concerns about the potential effects of exposure to radio-frequency electromagnetic fields remain. The aim of the present study was to explore socio-demographic predictors of mobile phone ownership as well as call frequency and call time duration.

Methods We analysed data from the baseline assessment of the Study of Cognition, Adolescents and Mobile Phones (SCAMP), which was collected between 2014 and 2016. SCAMP is a prospective secondary school-based cohort study established to investigate whether the use of mobile phones and other wireless devices is associated with cognitive, behavioural, educational, and physical and mental health outcomes. Pupils from 39 secondary schools (26 state, 13 independent) in and around London provided self-report data on mobile phone ownership and mobile phone use, including phone call frequency and call time duration. Multiple logistic regression analyses were performed using age, sex, ethnicity and parental socioeconomic classification to predict current mobile phone ownership and mobile phone use.

Results n=6616 pupils participated in the computer assessment at baseline, 83% of whom reported to own a mobile phone. We found a 62% increase in the odds of owning a phone for every year increase in age. Black, Asian and Mixed ethnicity was associated with lower odds of owning a phone compared to White ethnicity. Membership in a lower socioeconomic class was associated with lower odds of mobile phone ownership. We found that with increasing age pupils reported more frequent phone calls, and longer call time duration on weekends. Females reported more phone use than males. Black or Mixed ethnicity was associated with higher levels of phone use compared to White ethnicity, while Asian pupils reported lower phone use. No associations between phone use and socioeconomic classification were found.

Conclusion We have shown that differences in the socio-demographic characteristics of pupils are associated with variation in mobile phone ownership as well as call frequency and call time duration. The socio-demographic characteristics that were associated with higher levels of mobile phone ownership were in most cases not associated with higher levels of mobile phone use.