Abstract
OBJECTIVES: To investigate changes in children's television and computer time according to three socio-economic status (SES) indicators. DESIGN: Prospective cohort study. METHODS: Data were drawn from the European Youth Heart Study and included longitudinal data collected in 1997 and 2003 in Denmark. Television and computer time were self-reported by children. Parental education, income and ethnicity were parent-reported. Baseline data were available for 549 children (47.0% boys, 9.6 years). Generalized linear mixed models analyzed whether changes in television and computer time from baseline to follow-up differed according to the SES-indicators. RESULT: TV viewing time increased with 25% over time (ExpB = 1.25, 95% CI = 1.04-1.50). At both time points, children with two higher educated parents viewed 25% less hours of television than children with no higher educated parents (ExpB = 0.75, 95% CI = 0.60-0.94) and one higher educated parent (ExpB = 0.75, 95%CI = 0.59-0.97). Among children with no higher educated parents the odds of being in a higher category of computer time increased with 80% over time (OR = 1.80, 95% CI = 1.24-2.60). Among children with two higher educated parents the odds of being in a higher category of computer time decreased with 45% over time (OR = 0.55, 95% CI = 0.32-0.94). The association with ethnicity showed that white children had 42% lower odds (OR = 0.58; 95% CI = 0.34-1.00) of being in a higher category of computer time than non-white children. No significant associations were found for parental income. CONCLUSIONS: The most important SES measure of screen-based behaviors in children was parental education. Ethnicity was only associated with computer time. Financial resources were less relevant for changes in television viewing and computer use.