Purpose: To develop a valid and feasible short-form corner store audit tool (SCAT) that could be used in-store or over the phone to capture the healthfulness of corner stores.

Design: Nonexperimental.

Setting: Four New Jersey cities.

Subjects: Random selection of 229 and 96 corner stores in rounds 1 and 2, respectively.

Measures: An adapted version of the Nutrition Environment Measures Survey for Corner Stores (NEMS-CS) was used to conduct in-store audits. The 7-item SCAT was developed and used for round 2 phone audits.

Analysis: Exploratory factor analysis and item response theory were used to develop the SCAT.

Results: The SCAT was highly correlated with the adapted NEMS-CS ( r = .79). Short-form corner store audit tool scores placed stores in the same healthfulness categories as did the adapted NEMS-CS in 88% of the cases. Phone response matches indicated that store owners did not distinguish between 2% and low-fat milk and tended to round up the fruit and vegetable count to 5 if they had fewer varieties.

Conclusion: The SCAT discriminates between higher versus lower healthfulness scores of corner stores and is feasible for use as a phone audit tool.

In response to lack of access to healthy foods, many low-income communities are instituting local healthy corner store programs. Some stores also participate in the United States Department of Agriculture's Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) and the Supplemental Nutrition Assistance Program (SNAP). This study used two assessment tools to compare the healthfulness of offerings at stores participating in local healthy store programs (upgraded stores), WIC, and/or SNAP to that of similar non-participating stores.

Based on store audits conducted in 315 New Jersey corner stores in 2014, we calculated healthy food availability scores using subsections of the Nutrition Environment Measures Survey for Corner Stores (NEMS-CS-Availability) and a short-form corner store audit tool (SCAT). We used multivariable regression to examine associations between program participation and scores on both instruments.

Adjusting for store and block group characteristics, stores participating in a local healthy store program had significantly higher SCAT scores than did non-participating stores (upgraded: M = 3.18, 95% CI 2.65–3.71; non-upgraded: M = 2.52, 95% CI 2.32–2.73); scores on the NEMS-CS-Availability did not differ (upgraded: M = 12.8, 95% CI 11.6–14.1; non-upgraded: M = 12.5, 95% CI 12.0–13.0). WIC-participating stores had significantly higher scores compared to non-participating stores on both tools. Stores participating in SNAP only (and not in WIC) scored significantly lower on both instruments compared to non-SNAP stores.

WIC-participating and non-SNAP corner stores had higher healthfulness scores on both assessment tools. Upgraded stores had higher healthfulness scores compared to non-upgraded stores on the SCAT.

Objective

In response to recent national efforts to increase the availability of healthy food in small stores, we sought to understand the extent to which small food stores could implement the newly published Healthy Small Store Minimum Stocking Recommendations and reflect on the new US Department of Agriculture Food and Nutrition Service's final rule for stocking of staple foods for Supplemental Nutrition Assistance Program–approved retailers.

Design

We collected qualitative and quantitative data from 57 small stores in four states (Arizona, Delaware, Minnesota, and North Carolina) that accepted Supplemental Nutrition Assistance Program but not Special Supplemental Nutrition Assistance Program for Women, Infants, and Children benefits. Data from semistructured, in-depth interviews with managers/owners were transcribed, coded, and analyzed. We collected quantitative store inventory data onsite and later performed descriptive analyses.

Results

Store interviews revealed a reluctant willingness to stock healthy food and meet new recommendations. No stores met recommended fruit and vegetable stocking, although 79% carried at least one qualifying fruit and 74% carried at least one qualifying vegetable. Few stores met requirements for other food categories (ie, whole grains and low-fat dairy) with the exception of lean proteins, where stores carrying nuts or nut butter were more likely to meet the protein recommendation. Water and 100% juice were widely available and 68% met basic healthy beverage criteria.

Conclusions

In contrast to the inventory observed, most owners believed store stock met basic recommendations. Further, findings indicate that small stores are capable of stocking healthy products; however, technical and infrastructure support, as well as incentives, would facilitate shifts from staple to healthier staple foods. Retailers may need support to understand healthier product criteria and to drive consumer demand for new products.

Programs such as the Healthy Corner Store Initiative have been widely adopted in recent years to increase the availability of healthy foods in small retail food stores. Valid and reliable measures are necessary to evaluate the effectiveness of these programs. The validated instruments currently available for assessments require in-person evaluations, with surveys taking up to 30 minutes per store to complete. This instrument was developed by researchers at Arizona State University to simplify the process of evaluating the effectiveness of healthy store interventions, and to enable community partners and practitioners to conduct their own evaluations of food access. The SCAT was validated against an adapted version of the Nutrition Environment Measures Survey for Corner Stores, and tested for feasibility of use over the telephone. The SCAT was found to discriminate between corner stores in the top 20% of healthfulness scores from those in the lower 80% with 89% accuracy.

In 2015 a panel of experts was convened by Healthy Eating Research, a program of the Robert Wood Johnson Foundation, to establish a set of minimum guidelines small retail food stores could reach to be classified as meeting basic or preferred stocking levels. Work is currently in progress to assess how the SCAT scores correlate with basic and preferred levels. 

Individuals in urban low-income areas often do not have easy access to large grocery stores and supermarkets, and regularly shop at nearby small/corner stores. These stores stock an abundance of processed, energy-dense, nutrient poor foods, combined with few nutrient-dense products. A high concentration of small/corner stores is associated with poor diets by nearby residents. Interventions that target small food stores for increasing the availability and sale of healthy foods have been launched in many communities, and validated survey instruments have been developed to evaluate the effectiveness of the interventions. However, in-store surveys can take up to thirty minutes to conduct and require individual visits from investigators. Many projects assess the food environment in a large number of stores spread across broad geographical areas, making in-person evaluations infeasible and resource-prohibitive. The purpose of this study was to develop a valid and feasible short survey that could be used in-store or over the phone to capture the healthfulness of corner stores. An adapted version of the Nutrition Environment Measures Survey for Corner Stores (NEMS-CS) was used to conduct store audits of 230 corner stores in four New Jersey cities. Audit results were used in exploratory factor analysis and item response theory to develop a seven-item survey. The short survey was highly correlated with the full survey (r=0.79), and the short survey's classification of stores as healthy (top 20% of scores) versus unhealthy (bottom 80% of stores) matched NEMS-CS categorizations in 88% of cases. A second round of audits was conducted in 100 corner stores to confirm the validity of the seven-item survey and to test its feasibility as a phone audit tool. Complete phone responses were obtained from 86% of stores. Response matches indicated that store owners did not distinguish between 2% and low-fat milk, and tended to round up the fruit and vegetable count to five if they had fewer varieties. The seven-item short survey discriminates between healthy and unhealthy stores and is feasible for use as a phone audit tool.