Short-term Temporal Stability in Observed Retail Food Characteristics

ObjectiveUse 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.DesignIn-person observations of retail food stores at 2 time points, 2 weeks apart.SettingSouthwest Chicago, IL.Sample157 food stores.Main Outcome MeasuresAvailability 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.AnalysisTemporal stability was tested for availability using a McNemar test and for price and quality using a Wilcoxon signed-rank test.ResultsMeasures of food availability and prices as well as fresh produce quality at stores were generally stable at the 2 time points.Conclusions and ImplicationsThis study suggests that a single observation may be sufficient to accurately characterize within-season food availability, food prices, and fresh produce quality.