Assessing the community food environment: Results from a food store reliability study

Background: Research has demonstrated that factors in the built environment, such as the availability and characteristics of food retail outlets, may impact dietary behaviors. Understanding these relationships requires the reliable measurement of food outlet characteristics. Methodology: An inter-rater reliability study was conducted in 120 food stores (including supermarkets, grocery, convenience, discount department and other stores) in the Chicago MSA. Observational data were collected for several variables, including availability and pricing of food and beverage products; counts of total fresh, frozen, and canned fruit and vegetable options; and number of exterior advertisements. Results: Preliminary results indicate that inter-rater reliability for measures of general availability was excellent (Kappa ≥ 0.80) for all products except a limited number of beverage items (juice drinks, juice boxes, and powdered drinks). Reliability for price measures (for specified brands and package sizes) was more variable; preliminary results show that reliability was low (ICC = 0.35 - 0.55) for the price of soda, candy and bottled water. Inter-rater reliability was excellent for the total number of food and beverage ads on the building exterior (ICC ≥ 0.94), though slightly lower for number of ads on the store property (ICC = 0.68 for count of beverage ads on store property). Discussion: Results from this study indicate that product availability, pricing and promotion can be reliably obtained from community food stores through observational methods. Lessons learned will be discussed and applied to an upcoming nationwide study of both the food and physical activity environments in 150-200 communities.