Design and methods of the Healthy Kids & Families study: a parent-focused community health worker-delivered childhood obesity prevention intervention

Background
One third of U.S. children and two thirds of adults are overweight or obese. Interventions to prevent obesity and thus avert threats to public health are needed. This paper describes the design and methods of the Healthy Kids & Families study, which tested the effect of a parent-focused community health worker (CHW)- delivered lifestyle intervention to prevent childhood obesity.

Methods
Participants were English or Spanish-speaking parent-child dyads (n = 247) from nine elementary schools (grades K-6) located in racial/ethnically diverse low-income communities in Worcester, Massachusetts. Using a quasi-experimental design with the school as the level of allocation, the study compared the lifestyle intervention vs. an attention-control comparison condition. The lifestyle intervention was guided by social cognitive theory and social ecological principles. It targeted the child’s social and physical home environment by intervening with parental weight-related knowledge, beliefs, and skills for managing child obesogenic behaviors; and addressed families’ needs for community resources supportive of a healthy lifestyle. The two-year CHWdelivered intervention was structured based on the 5As model (Agenda, Assess, Advise, Assist, Arrange follow up) and included two in person sessions and two telephone follow-ups per year with the parent, with a personalized letter and print materials sent after each contact. Parents also received quarterly newsletters, Facebook messages, and invitations to community events. The attention-control comparison condition used the same format and contact time as the intervention condition, but targeted positive parenting skills. Measurements occurred at baseline, and at 6-, 12-, 18- and 24-month follow-up. Assessments included anthropometrics, accelerometry, global positioning system (GPS), and self-report surveys. The primary outcome was child body mass index (BMI) z score. Secondary outcomes were parent BMI; and parent and child diet, physical activity, sedentariness, and utilization of community resources supportive of a healthy lifestyle.

Discussion
A CHW-delivered parent-focused lifestyle intervention may provide a translatable model for targeting the high priority public health problem of childhood obesity among low-income diverse communities. If demonstrated effective, this intervention has potential for high impact.