Efficacy methods to evaluate health communication and marketing campaigns.

Communication and marketing are growing areas of health research, but relatively few rigorous efficacy studies have been conducted in these fields. In this article, we review recent health communication and marketing efficacy research, present two case studies that illustrate some of the considerations in making efficacy design choices, and advocate for greater emphasis on rigorous health communication and marketing efficacy research and the development of a research agenda. Much of the outcomes research in health communication and marketing, especially mass media, utilizes effectiveness designs conducted in real time, in the media markets or communities in which messages are delivered. Such evaluations may be impractical or impossible, however, imiting opportunities to advance the state of health communication and marketing research and the knowledge base on effective campaign strategies, messages, and channels. Efficacy and effectiveness studies use similar measures of behavior change. Efficacy studies, however, offer greater opportunities for experimental control, message exposure, and testing of health communication and marketing theory. By examining the literature and two in-depth case studies, we identify advantages and limitations to efficacy studies. We also identify considerations for when to adopt efficacy and effectiveness methods, alone or in combination. Finally, we outline a research agenda to investigate issues of internal and external validity, mode of message presentation, differences between marketing and message strategies, and behavioral outcomes.