The Fit Study: Design and rationale for a cluster randomized trial of school-based BMI screening and reporting

Abstract

Background In the U.S., 25 states conduct body mass index (BMI) screening in schools, just under half of which report results to parents. While some experts recommend the practice, evidence demonstrating its efficacy to reduce obesity is lacking, and concerns about weight-related stigma have been raised. Methods/Design The Fit Study is a 3-arm cluster-randomized trial assessing the effectiveness of school-based BMI screening and reporting in reducing pediatric obesity and identify unintended consequences. Seventy-nine elementary and middle schools across California were randomized to 1 of 3 arms: 1) BMI screening and reporting; 2) BMI screening only; or 3) no BMI screening or reporting. In Arm 1 schools, students were further randomized to receive reports with BMI results alone or both BMI and fitness test results. Over 3 consecutive years, staff in schools in Arms 1 and 2 will measure students’ BMI (grades 3–8) and additional aspects of fitness (grades 5–8), and students in grades 4–8 in all Arms will complete surveys to assess weight-based stigmatization. Change in BMI z-score will be compared between Arm 1 and Arm 2 to determine the impact of BMI reporting on weight status, with sub-analyses stratified by report type (BMI results alone versus BMI plus fitness results) and by race/ethnicity. The potential for BMI reports to lead to weight-based stigma will be assessed by comparing student survey results among the 3 study Arms. Discussion This study will provide evidence on both the benefit and potential unintended harms of school-based BMI screening and reporting.

Food Insecurity Is Associated with Body Dissatisfaction among Children in California

“…For this investigation, baseline data were collected during the 2014–2015 and 2015–2016 school years (two separate cohorts) from a randomized trial of BMI screening and reporting in 79 California public schools. 19 Only students in the intervention arm of the study in which BMI was assessed were included in the analysis (n=19,046). Of those, 4,278 students with missing data were excluded from analysis.…”

Parents Recall of, and Reactions to, School-Based BMI Reports

“…This repeated cross-sectional study used parent survey data from the Fit Study, a 3-year, cluster-randomized trial examining the impact of school-based BMI reporting on pediatric obesity. 15 Students in the Fit Study (grades 3-7 in California public schools) were recruited in two cohorts during the 2014-15 and 2015-16 school years. Participating students in the intervention arm had their BMI assessed in school in the spring of 2015 and 2016; students in grades 5-8 also participated in 5 fitness tests that assessed strength, flexibility, and aerobic capacity.…”

Effect of school-based body mass index reporting in California public schools: a randomized clinical trial

“…Schools were the unit of randomization and intervention; recruitment and study design have been described previously. 22 The study protocol and statistical analysis plan are provided in the Supplemental Materials.…”

“…Change in BMI z-score 24 . School staff assessed BMI among participating Arm 1 and 2 students in grades 3-8, using research-grade equipment 22 ; height and weight measurements were equivalent to those of trained researchers. 27 The California Department of Education excused Control (Arm 3) schools from assessing BMI during study years; however, all study schools conducted fitness assessments per usual.…”