RESUMEN
Objective: To help inform decisions regarding the equitable implementation of obesity interventions, we examined whether interventions were equitably reaching the most vulnerable communities, identified communities that received fewer interventions than expected, and estimated the effect of 'dose' of interventions on obesity prevalence. Methods: We created a database to identify and characterize obesity-related interventions implemented in Los Angeles County from 2005 to 2015 linked to community-level sociodemographic and obesity prevalence data. We ran generalized linear models with a Gamma distribution and log link to determine if interventions were directed toward vulnerable communities and to identify communities that received fewer interventions than expected. We ran fixed-effects models to estimate the association between obesity prevalence and intervention strategy count among preschool-aged children enrolled in the Special Supplemental Nutrition Assistance Program for Women Infants and Children. Results: We found that interventions targeted vulnerable communities with high poverty rates and percentages of minority residents. The small cluster of communities that received fewer interventions than expected tended to have poor socioeconomic profiles. Communities which received more intervention strategies saw greater declines in obesity prevalence (ß = -0.023; 95 % CI: -0.031, -0.016). Conclusions: It is important to determine if interventions are equitably reaching vulnerable populations as resources to tackle childhood obesity become available. Evaluating the population impact of multiple interventions implemented simultaneously presents methodological challenges in measuring intervention dose and identifying cost-effective strategies. Addressing these challenges must be an important research priority as community-wide interventions involve multiple intervention strategies to reduce health disparities.
RESUMEN
The recognition of the role of the environment in contributing to the obesity epidemic has led to increasing efforts to address obesity through environmental or place-based approaches in the past decade. This has challenged the use of the quasi-experimental design for evaluating community interventions. The objective of this study is to describe the development of an index of dose of exposure to community interventions that impact early childhood obesity. The goal is to provide an alternative means for evaluating the impact of multiple intervention strategies that target the same community at the same time. Two workgroups developed domains, constructs and protocols for estimating a "community intervention dose index" (CIDI). Information used to develop the protocol came from multiple sources including databases and reports of major funding organizations on obesity-related interventions implemented in Los Angeles County from 2005 to 2015, key informant interviews, and published literature. The workgroups identified five domains relevant to the consideration of dose of exposure to interventions: physical resources, social resources, context, capacity development, and programs and policies; developed a system for classifying programs and policies into macro- and micro-level intervention strategies; and sought ratings of strategy effectiveness from a panel of 13 experts using the Delphi technique, to develop an algorithm for calculating CIDI that considers intervention strength, reach and fidelity. This CIDI can be estimated for each community and used to evaluate the impact of multiple programs that use a myriad of intervention strategies for addressing a defined health outcome.
