Maternal knowledge explains screen time differences 2 and 3.5 years post-intervention in INFANT.

Very few early childhood interventions have observed sustained effects regarding television viewing and none have examined the mechanisms behind sustained intervention effects at long-term follow-ups. Thus, the aim of this study was to investigate potential mechanisms relating to the maintained intervention effect on television viewing at two long-term follow-ups in the Melbourne Infant Feeding Activity and Nutrition Trial (INFANT). INFANT was a cluster-randomised controlled trial. At the 2- and 3.5-year follow-ups, a total of 262 infant/mother pairs had complete information. Television viewing was assessed via a questionnaire at both follow-ups and six potential mediators were measured post-intervention (i.e. 15 months after baseline). Causal mediation analysis was conducted. At the 2- and 3.5-year follow-ups, the positive impacts of INFANT on maternal television viewing knowledge were maintained (B = 0.34 units; 95% confidence interval (CI95): 0.21, 0.48). An indirect effect of the intervention on reducing children's television viewing time was observed at the 2- and 3.5-year follow-ups (B = -11.73 min/day; CI95: -22.26, -3.28 and B = -4.78 min/day; CI95: -9.48, -0.99, respectively) via improved maternal television viewing knowledge.Conclusion: The positive impacts of INFANT on maternal television viewing knowledge were maintained at both follow-ups, with better maternal knowledge associated with less television viewing time in their children. These results have implications for paediatricians and healthcare professionals as educating new parents early on regarding screen time may lead to the development of healthier screen time habits that are sustained through to the pre-school years. What is Known: • Lifestyle behaviours inclusive of screen time have been found to be established before the pre-school years and track. • Few trials have evaluated the long-term mechanisms related to maintained intervention effectiveness. What is New: • This study shows the positive impacts of a low-dose intervention on maternal television viewing knowledge at two long-term follow-ups. • Better maternal television viewing knowledge was associated with less television viewing time in their children.