Developing NEMS
NEMS Measures Development
The objectives of the original Nutrition Environment Measures Study were to:
- Develop measures of nutrition environments and survey retail and food service outlets (stores and restaurants)
- Test the inter-rater and test-retest reliability of NEMS instruments
The Measures
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 measures are indicators and are not meant to be an extensive inventory of individual food outlets. Since their public release, many researchers and practitioners have used the measures in their own research and communities.
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 in the study, 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 by one of the original raters who had rated the outlet previously.
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. The hypotheses were confirmed. Findings for measures of restaurant environments were similar.
The results for each specific NEMS tool can be found in their related published journal articles: