Health Campaign Channels Tradeoffs Among Reach, Specificity, and Impact

Abstract

The authors examined comparative effects of five health campaign channels used in the Stanford Five-City Multifactor Risk Reduction Project. Three distinct criterion variables were evaluated: (a) reach, measured as the number of messages intervention community residents remembered; (b) specificity, assessed by examining whether the campaign differentially reached those who were already knowledgeable and practicing cardiovascular disease risk reduction; and (c) impact, defined as the amount of knowledge gained during the 5-year campaign. Path analyses revealed that reach was highest for tip sheets. Specificity was highest for booklets and then television programs. Newspaper messages appeared to have the most impact, followed by booklets and television public service announcements, tip sheets, and finally, television programs. Channels varied according to reach, specificity, and impact, and each of these criteria were distinct. No channel was optimal for all three of the outcome measures, suggesting that channel selection involves tradeoffs among different types of effects.