The Growing Healthy study is a randomized controlled
trial (RCT). Classrooms (n = 75) are randomized through
an automated system to one of 3 study arms (200 children
per arm): (1) POPS; (2) POPS + IYS; or (3) Usual
HS Exposure. Each HS program hosts all 3 study arms,
and all children in an individual classroom participate in
only one arm. Only one classroom participates per physical
school site to prevent cross-contamination across
study arms and ensure that participants are blind to
group assignments. Families are assigned to study arm
as a function of their classroom assignment. Every effort
is made to match intervention and comparison classrooms
on demographic characteristics in order to
minimize differences not due to the intervention (e.g., %
minority race/ethnicity, teacher education).
Data are collected pre-intervention (in the fall) and
post-intervention (in the spring). Interventions occur between
October and April of the academic year. Process
implementation data are collected throughout the study.
Children are enrolled in each of 4 academic years, with
50 children enrolled into each of the 3 study arms per
year. Data collectors are separate from the interventionists,
and blinded to the study arm to which participants