Evaluation of a pragmatic trial of a collaborative school-based obesity prevention intervention in a low-income urban district

Broader adoption of effective school-based obesity prevention interventions is critical to the success of ongoing efforts to address the childhood obesity epidemic. School-level barriers to adopting evidence-based interventions may be overcome by empowering school-level leaders to select appropriate intervention components. We used a quasi-experimental pragmatic trial design to evaluate a tailored obesity prevention intervention in 9 schools in a mid-sized urban school district in upstate New York from fall 2013 to spring 2016. We analyzed repeated height and weight measurements from an existing district screening system on 5882 students from intervention and control schools matched using propensity score methods. We assessed diet and physical activity changes in intervention schools using surveys and direct observation. The intervention led to a change of -0.27 (p = 0.026, 95% Confidence Interval (CI): -0.51, - 0.03) and -0.28 (p = 0.031, 95% CI: -0.54, -0.03) BMI units in spring 2014 and fall 2014, respectively. There were no significant differences between intervention and control from spring 2015 to spring 2016. Despite the lack of sustained effects on BMI, we demonstrated the potential of supporting school leaders in a low-income district to implement supportive policy and practice changes and of using an existing BMI screening system to reduce the burden of health promotion evaluation.