PT - JOURNAL ARTICLE AU - Jo Salmon AU - Lauren Arundell AU - Ester Cerin AU - Nicola Dawn Ridgers AU - Kylie D Hesketh AU - Robin M Daly AU - David Dunstan AU - Helen Brown AU - Jacqui Della Gatta AU - Paul Della Gatta AU - Mai J M Chinapaw AU - Lauren Shepphard AU - Marj Moodie AU - Clare Hume AU - Vicki Brown AU - Kylie Ball AU - David Crawford TI - Transform-Us! cluster RCT: 18-month and 30-month effects on children’s physical activity, sedentary time and cardiometabolic risk markers AID - 10.1136/bjsports-2022-105825 DP - 2023 Mar 01 TA - British Journal of Sports Medicine PG - 311--319 VI - 57 IP - 5 4099 - http://bjsm.bmj.com/content/57/5/311.short 4100 - http://bjsm.bmj.com/content/57/5/311.full SO - Br J Sports Med2023 Mar 01; 57 AB - Objective To test the efficacy of the Transform-Us! school- and home-based intervention on children’s physical activity (PA), sedentary behaviour (SB) and cardiometabolic risk factor profiles.Methods A 30-month 2×2 factorial design cluster randomised controlled trial delivered in 20 primary schools (148 Year 3 classes) in Melbourne, Australia (2010–2012), that used pedagogical and environmental strategies to reduce and break up SB, promote PA or a combined approach, compared with usual practice. Primary outcomes (accelerometry data; n=348) were assessed at baseline, 18 and 30 months. Secondary outcomes included body mass index (BMI) and waist circumference (WC) (n=564), blood pressure (BP) (n=537) and biomarkers (minimum n=206). Generalised linear mixed models estimated the interactive effects of the PA and SB interventions on the outcomes. If there was no interaction, the main effects were assessed.Results At 18 months, there were intervention effects on children’s weekday SB (−27 min, 95% CI: −47.3 to −5.3) for the PA intervention, and on children’s average day PA (5.5 min, 95% CI: 0.1 to 10.8) for the SB intervention. At 30 months, there was an intervention effect for children’s average day SB (−33.3 min, 95% CI: −50.6 and −16.0) for the SB intervention. Children’s BMI (PA and SB groups) and systolic BP (combined group) were lower, and diastolic BP (PA group) was higher. There were positive effects on WC at both time points (SB intervention) and mixed effects on blood parameters.Conclusions The Transform-Us! PA and SB interventions show promise as a pragmatic approach for reducing children’s SB and adiposity indicators; but achieving substantial increases in PA remains challenging.Trial registration ISRCTN83725066; ACTRN12609000715279.Data are available upon reasonable request.