| Study summary: |
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We propose a 2-arm, parallel group, randomized controlled trial to test the efficacy of an
after school ethnic dance program plus a culturally-tailored, home-based screen time
reduction intervention to reduce weight gain (body mass index) among lower socioeconomic
status, pre-adolescent Latina girls. The control group will receive an “active-placebo”
information-based health education intervention. A total of 240 7-9 year old girls will be
randomized to the two conditions, and both interventions will last for the full 2-year
period of the study for each girl.
Latina girls are at increased risk of obesity and obesity-related morbidities. However,
effective and generalizable obesity prevention programs for this rapidly growing population
are not available. After school ethnic dance programs are highly motivating, and an
innovative approach to providing a large “dose” of moderate-to-vigorous physical activity
for Latina girls. After school programs may also indirectly reduce sedentary behavior and
improve diet. Dance is fun for pre-adolescent girls, it plays an important social and
cultural role in Latino communities, and after school dance classes are a potentially
generalizable “environmental” intervention strategy. Our past pilot studies and ongoing
trials of ethnic dance interventions demonstrate that (1) dance is a highly attractive and
feasible form of activity for pre-adolescent girls and (2) a dance intervention can result
in reduced weight gain (BMI) and increased fitness among girls.
Latina girls are also heavy consumers of screen-based media, television, videotapes/DVDs and
video games. Excessive screen time is considered one of the most modifiable causes of
childhood obesity. We propose a culturally-tailored, home-based screen time reduction
intervention, delivered by bilingual, Latina, Community Health Advisors (CHAs). Our prior
and ongoing studies demonstrate the feasibility and potential efficacy of (1) reducing
children’s screen time to reduce weight gain and (2) providing home-based behavior change
interventions to low-income Latino families using CHAs. All interventions will be further
developed, revised, and pilot-tested with Latina girls and their families through formative
research.
240 girls Latina girls will be recruited over 18 months from six public elementary schools
serving low-income Latino communities in northern CA. Measures will be collected in girls’
homes at baseline, 6, 12, 18 and 24 months, including height and weight, waist
circumference, triceps skinfold thickness, blood pressure and resting heart rate, physical
activity monitoring by accelerometry, media use, 24-hour dietary recalls, weight concerns,
depressive symptoms, school performance, sexual maturation, and demographics. Body Mass
Index (BMI) is the primary outcome measure. The primary outcome analysis will compare
individual trajectories of change in BMI in the treatment and control groups over the entire
two-year course of the trial, using random regression models. The study is powered (90%) to
detect a clinically-significant effect. Specific Aims include:
1. To test the efficacy of a combined, after school ethnic dance and home-based screen
time reduction intervention to reduce weight gain (BMI) over 2 years.
Primary hypothesis: Compared to controls, girls in the treatment group will
significantly reduce their weight gain (BMI) over the two-year study period.
2. To test the effects of a combined, after school ethnic dance and home-based screen time
reduction intervention on secondary outcomes over two years.
Secondary hypotheses: Compared to controls, girls in the treatment group will
significantly reduce their waist circumference, triceps skinfold thickness, systolic
and diastolic resting blood pressures, resting heart rate, television, videotape/DVD
and video game use, meals eaten with TV, daily dietary energy intake, percent of energy
from fat, weight concerns and depressive symptoms, and significantly increase their
daily physical activity, daily moderate to vigorous physical activity, liking for
physical activity, and school performance.
3. To evaluate potential demographic, cultural, psychological, and biological moderators
and mediators of intervention effects on BMI and secondary outcomes, to evaluate
correlates and risk factors for change in BMI and secondary outcomes, and to evaluate
intervention delivery variables and their relationships to outcomes. |