Video AbstractBACKGROUND AND OBJECTIVES: Heterogeneity in risk among low-income families suggests the need for tiered interventions to prevent disparities in school readiness. Smart Beginnings (SB) integrates two interventions: Video Interaction Project (VIP) (birth to 3 years), delivered universally to low-income families in pediatric primary care, and Family Check-Up (6 months to 3 years), targeted home visiting for families with additional family risks. Our objective was to assess initial SB impacts on parent-child activities and interactions at 6 months, reflecting early VIP exposure.METHODS: Two-site randomized controlled trial in New York City (84% Latinx) and Pittsburgh (81% Black), with postpartum enrollment and random assignment to treatment (SB) or control. At 6 months, we assessed parent-child interactions through surveys (StimQ, Parenting Your Baby) and observation (video-recorded play, coded by using Parent-Child Interaction Rating Scales – Infant Adaptation).RESULTS: A total of 403 families were enrolled at child’s birth (201 treatment) with 362 (89.8%) assessed at 6 months. Treatment families had increased StimQ, including total score (Cohen’s d = 0.28; P < .001) and domains reflecting reading (d = 0.23; P = .02) and teaching (d = 0.25; P = .01), and Parent-Child Interaction Rating Scales – Infant Adaptation, including a cognitive stimulation factor (d = 0.40; P < .001) and domains reflecting support for cognitive development (d = 0.36; P < .001), and language quantity (0.40; P < .001) and quality (d = 0.37; P < .001). Thus, significant effects emerged across a broad sample by using varied methodologies.CONCLUSIONS: Findings replicate and extend previous VIP findings across samples and assessment methodologies. Examining subsequent assessments will determine impacts and feasibility of the full SB model, including potential additive impacts of Family Check-Up for families at elevated risk.