Abstract
Objective: Despite the increase in the volume and importance of food environment research, there is a general lack of reliable measurement tools. This study presents the development and reliability assessment of a tool for measuring consumer nutrition environment in urban food stores.
Design: Cross-sectional design.
Setting: A racially diverse downtown portion (6 ZIP code areas) in Albany, New York.
Participants: A sample of 39 food stores was visited by our research team in 2009 to 2010. These stores were randomly selected from 123 eligible food stores identified through multiple government lists and ground-truthing.
Main Outcome Measures: The Food Retail Outlet Survey Tool was developed to assess the presence of selected food and nonfood items, placement, milk prices, physical characteristics of the store, policy implementation, and advertisements on outside windows. For in-store items, agreement of observations between experienced and lightly trained surveyors was assessed. For window advertisement assessments, inter-method agreement (on-site sketch vs digital photo), and inter-rater agreement (both on-site) among lightly trained surveyors were evaluated. Percent agreement, Kappa, and prevalence-adjusted bias-adjusted kappa were calculated for in-store observations. Interclass correlation coefficients were calculated for window observations.
Results: Twenty-seven of the 47 in-store items had 100% agreement. The prevalence-adjusted bias-adjusted kappa indicated excellent agreement (>=0.90) on all items, except aisle width (0.74) and dark-green/orange colored fresh vegetables (0.85). The store type (nonconvenience store), the order of visits (first half), and the time to complete survey (>10 minutes) were associated with lower reliability in these 2 items. Both the inter-method and inter-rater agreements for window advertisements were uniformly high (intraclass correlation coefficient ranged 0.94-1.00), indicating high reliability.
Conclusions: The Food Retail Outlet Survey Tool is a reliable tool for quickly measuring consumer nutrition environment. It can be effectively used by an individual who attended a 30-minute group briefing and practiced with 3 to 4 stores.