Add-ons may infringe on the purpose of the survey. Cooperative efforts with other agencies, such as the American Cancer Society, the American Lung Association, and the American Diabetes Association, may be required. Some programs can be formatively evaluated only and results, if obtained in pilot testing, generalized to subsequent versions of the program. Generalization of results will be limited if new groups of participants differ demographically. Measuring distribution of materials or messages can be an inexpensive alternative for measuring change in awareness or knowledge.
Low cost is paralled by low precision in estimating impact.
Distribution may not be an adequate alternative, especially among population segments with low education or receptivity. Trends in risk factors and disease provide a measure of efficacy. The ability to discern the specific impact of AHA efforts from those of other agencies is limited. A registry of program participants permits audience characterization and follow-up. Registries can be costly in terms of staff time and participant burden.