MEASURES REGISTRY USER GUIDE
Measurement is a fundamental component of all forms of research and it is certainly true for research on childhood obesity. A top priority for the National Collaborative on Childhood Obesity Research (NCCOR) is to encourage consistent use of high-quality, comparable measures and research methods across childhood obesity prevention and research.
NCCOR’s Measures Registry—a free, online repository of articles about measures—helps achieve this aim. It is widely recognized as a key resource that gives researchers and practitioners access to detailed information on measures in one easy-to-search location. The Registry’s measures focus on four domains that can influence childhood obesity on a population level:
- Individual Diet
- Food Environment
- Individual Physical Activity
- Physical Activity Environment
NCCOR: WORKING TOGETHER TO REVERSE CHILDHOOD OBESITY
NCCOR is a partnership of the four leading funders of childhood obesity research: The Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), the Robert Wood Johnson Foundation (RWJF), and the U.S. Department of Agriculture (USDA). These four leaders joined forces in 2008 to continually assess the needs in childhood obesity research, develop joint projects to address gaps and make strategic advancements, and work together to generate fresh and synergetic ideas to reduce childhood obesity. For more information about NCCOR, visit www.nccor.org.
Even with this resource, however, it can be challenging for users to choose the most appropriate measures for their work. To address this need, NCCOR began the Measures Registry User Guide project in 2015. Organized by the same four domains as the Measures Registry, the User Guides are designed to provide an overview of measurement, describe general principles of measurement selection, present case studies that walk users through the process of using the Measures Registry to select appropriate measures, and direct researchers and practitioners to additional resources and sources of useful information (Figure 1). The User Guides will help move the field forward by fostering more consistent use of measures, which will allow for standardization, meta-analyses, and synthesis.
Figure 1: NCCOR Measures Registry User Guides
Overview of the Individual Diet Measures Registry User Guide
This User Guide is specific to individual dietary behaviors, for which a plethora of measures are available. Dietary behavior is complex, and so is its measurement.1 Nonetheless, measuring dietary behaviors can provide extremely useful information. However, due to the varying characteristics, strengths, and weaknesses of different measures, and corresponding degrees of appropriateness for particular applications, choosing the most appropriate tool for a given population and purpose can be a challenging task. The goal of this User Guide is to help researchers and practitioners make effective use of the Individual Diet domain within the Measures Registry, as well as complementary resources, to select the best possible measures to conduct population surveillance of dietary behavior, to assess dietary determinants of disease and health outcomes, and to evaluate policy and program interventions. The User Guide also aims to help users consider salient issues related to administration of measures, data analysis, and interpretation and reporting of the resulting findings. The User Guide does not provide a comprehensive summary of each of the measures, an evaluation of the measures, or a compilation of research using the measures, but rather, addresses concepts associated with the measurement of dietary behaviors broadly.
The focus of this User Guide on individual diet differentiates it from the complementary Guide on measures of the food environment. As such, this Guide is aimed at providing guidance on measuring diet among individuals. However, it is important to note that, for the purposes of childhood obesity research, data are typically captured at the level of individuals, but inferences are made at the level of groups or populations. For example, in the National Health and Nutrition Examination Survey (NHANES), dietary intake data are collected from individuals for the purpose of generating estimates of intake of certain components, such as fruits and vegetables or sugar-sweetened beverages, among different subgroups of the population, as well as examining influences of sociodemographic or other characteristics on dietary behavior.2 The measurement of dietary behavior at the level of individuals for the purposes of clinical assessment or counseling is outside of the scope of this Guide, though measures within the Registry may be applicable to these purposes. It is difficult to characterize the dietary behaviors of a given individual3; however, this is not necessary for research questions related to estimating consumption of particular dietary components in a population or assessing associations between dietary intake and other variables, for example.1
Within the Registry, dietary behavior measures are identified as tools and methods used to assess individuals’ diets. For the purpose of this User Guide, methods relate to a particular approach to the collection of dietary behavior (e.g., food frequency questionnaire), and tools refer to a particular measure (e.g., Calcium Food Frequency Questionnaire). Many measures within the Registry reflect tools that are variations on the same method.
Organization of this User Guide
In addition to this Introduction, this User Guide includes the following sections: