Evaluating community-based nutrition programs: comparing grocery store and individual-level survey measures of program impact

This paper examines whether an "environmental indicator"--a survey of grocery store product displays--can provide a realistic alternative to individual-level telephone surveys for the evaluation of community-based nutrition programs.

Telephone and grocery store measures were used separately to evaluate three community-level dietary interventions that were part of the Kaiser Family Foundation Community Health Promotion Grants Program (CHPGP). Both surveys were conducted in the three intervention and seven control communities at three points in time: 1988, 1990, and 1992. The grocery store survey recorded the relative availability of low-fat and high-fiber products and the amount of store-provided health-education information. Self-reported dietary intake of residents was obtained in the same communities using a telephone survey.

In the one community in which the intervention seemed to have contributed to reduced fat consumption, the grocery store and telephone surveys showed very similar relative changes for the only variable they had in common, low-fat milk consumption. In another community, both survey approaches indicated that there was no change or perhaps a slight worsening in the treatment relative to the controls. The third community produced the only contradictory results: the telephone survey suggested no change or perhaps a worsening, while the grocery store results were generally positive, though not statistically significant.

These results, combined with the much lower cost of the grocery store survey, justify further pursuit of environmental indicators as an evaluation tool.