About NEMS

NEMS Measures Development

The aims of the original Nutrition Environment Measures Study were to:

1. Develop measures of nutrition environments and survey retail and food service outlets (stores and restaurants)
2. Test the inter-rater and test-retest reliability of NEMS instruments
3. Examine sampling and generalizability issues

The NEMS measures focus on surveying community and consumer nutrition environments which include the type and location of food outlets, availability of healthful choices and information, pricing, promotion, and placement of healthier food products.

The third aim of NEMS is still in process as more data is collected for the NIK Study (Neighborhood Influences on Kids).

Ensuring Reliability

When raters are well trained and quality control is enhanced, the NEMS measures have demonstrated high reliability and validity. Proper training is necessary to ensure proper use of and/or adaptation of the measures.

To assess inter-rater reliability, two trained raters independently visited food outlets to complete the same set of assessments on the same day. To assess test-retest reliability, outlets were re-assessed within one month after the initial observations. Construct validity was assessed by comparing findings across different types of stores (grocery, convenience) and restaurants (sit-down, fast-food), and by comparing high- and low- income neighborhoods.

The measures were completed in 88 stores and 216 restaurants. The study yielded very high inter-rater reliability, and test-retest reliability ranged from .73 to 1.00 except for measures of fruit quality. Construct (discriminant) validity was examined by comparing the availability of healthful options in grocery stores versus convenience stores, and high- vs. low-income neighborhoods. These hypotheses were confirmed. Findings for measures of restaurant environments were similar.