Weight Status Measures Collected in the Healthy Communities Study

Abstract

The Healthy Communities Study is one of the largest studies to assess the relationship between characteristics of community programs and policies to prevent childhood obesity and obesity-related outcomes. The purpose of this paper is to describe the protocol that was developed for collecting the anthropometric data for the study and the procedures for analyzing the data. Data were collected from 2013 to 2015 and analyses will be completed by mid-2016. During in-home visits, Healthy Communities Study staff collected height, weight, and waist circumference measurements from child participants and height and weight measurements from adult participants. The protocol for obtaining these measurements was adapted from the protocol used by the National Health and Nutrition Examination Survey, with modifications to accommodate assessments conducted in homes rather than in a Mobile Examination Center. In addition to anthropometric data from in-home visits, the Healthy Communities Study collected retrospective height and weight measurements from the medical records of child participants. These data were used to calculate trajectories of BMI and BMI z-scores. The study implemented procedures for ensuring the accuracy of the in-home measurements and abstracted medical data. These procedures included automatically checking the ranges on entered data, reviewing data for end-digit patterns, and abstracting selected medical records using two independent abstractors to assess agreement. The collection of longitudinal height and weight measures will allow researchers to address several pressing questions related to how characteristics of community programs and policies are associated with obesity-related outcomes among children.

Community Policies and Programs to Prevent Obesity and Child Adiposity

“…Participants underwent a standard protocol to measure child height, weight, and waist circumference and information collection on demographic and background characteristics and nutrition and physical activity behaviors. 18 …”

“…18 Measures were taken twice and entered into the information management system, which checked for data quality (e.g., plausible values). Data quality was achieved through training and certification of field staff, repeated measurement, presence of supervising staff during selected in-home visits, and post-visit review of data.…”

Statistical Design Features of the Healthy Communities Study

“…With these outcomes observed on a large sample of children, data can be combined across communities to identify the program and policy attributes that are most closely associated with child outcomes at different stages of development. Power calculations demonstrated that the study can detect 4.9%–7.5% differences in current BMI associated with current indices of community-based program and policy intensity using cross-sectional models, and BMI change differences of less than 1% by combining longitudinal measures of BMI from medical records 18 with longitudinal indices of community-based program and policy intensity. 17 …”

“…standard protocol: current height/weight status of child, questionnaires from parent/child on physical activity and diet, and medical record abstraction to develop longitudinal BMI trajectories from entire sample 18–20 ;…”

“…21–26 Another attractive feature of the design is the ability to generate longitudinal BMI trajectories 27 up to 10 years in length on a sample of children within each community (combining BMI measures from medical record abstraction 18 with those from the household visit). These trajectories can be modeled as a function of the time series of standardized community scores.…”