Can measures of the grocery store environment be used to track community-level dietary changes?
BACKGROUND
This article examines whether an in-store unobtrusive survey of grocery store product displays can be used to track community-level dietary behavior.


METHODS
The survey was conducted in 12 western communities two different times to measure two aspects of the grocery store environment: (a) the relative availability of low-fat and high-fiber products and (b) the amount of store-provided health-education information. Self-reported dietary intake of residents was obtained in the same 12 communities using a telephone survey. We compared the individual and store-level measures both cross-sectionally and over time.


RESULTS
We found positive and statistically significant correlations between the availability of healthful products in stores and the reported healthfulness of individual diets in cross-sectional analyses, but correlations between changes over time in the two measures were weaker and not statistically significant. The variance of the grocery store measures was nonetheless sufficiently small that a grocery store survey of 15 stores in each of 8 communities (n = 120 surveys) had power comparable to that of a telephone survey of 200 individuals/community (n = 1,600) surveys, at a fraction of the cost.


CONCLUSIONS
Although the results provide further validation of cross-sectional measures of the grocery store environment, additional efforts are required to establish the validity of the grocery store survey as a method of measuring dietary change.
Cheadle
A
A
Department of Health Services, University of Washington, Seattle 98195.
Psaty
B M
BM
Curry
S
S
Wagner
E
E
Diehr
P
P
Koepsell
T
T
Kristal
A
A
D000329:Advertising; D003430:Cross-Sectional Studies; D004034:Diet Surveys; D004041:Dietary Fats / Q000008:administration & dosage; D004043:Dietary Fiber / Q000008:administration & dosage; D004777:Environment; D005247:Feeding Behavior; D005500:Follow-Up Studies; D005523:Food Supply; D006801:Humans; D052756:Nutritional Sciences / Q000193:education*; D015203:Reproducibility of Results; D013689:Telephone
D004041:Dietary Fats; D004043:Dietary Fiber