Short-term temporal stability in observed retail food characteristics.

Objective: Use of direct observation to characterize neighborhood retail food environments is increasing, but to date most studies have relied on a single observation. If food availability, prices, and quality vary over short time periods, repeated measures may be needed to portray these food characteristics. This study evaluated short-term (2-week), within-season temporal stability in retail food availability, prices, and quality.

Design: In-person observations of retail food stores at 2 time points, 2 weeks apart.

Setting: Southwest Chicago, IL.

Sample: 157 food stores.

Main Outcome Measures: Availability and prices of food items selected from the following food groups: fruit, vegetables, grains, meats and beans, and dairy, as well as fresh produce quality.

Analysis: Temporal stability was tested for availability using a McNemar test and for price and quality using a Wilcoxon signed-rank test.

Results: Measures of food availability and prices as well as fresh produce quality at stores were generally stable at the 2 time points.

Conclusions And Implications: This study suggests that a single observation may be sufficient to accurately characterize within-season food availability, food prices, and fresh produce quality.