This paper reviews the research that has been done on mass media effects in health communication: breakthroughs in treatment, rising costs of medical care, innovations in the organization of health care, governmental involvement, the rise in malpractice litigation, and so on. The conceptual framework employed proposes a continuum of audience involvement--in some studies, audience reaction is no more than implied, while in others, audience interaction is examined to some degree. This framework sets the stage for the paper's main thesis: that methods need to be employed in media-effects studies so that audience interaction may be taken into full account. It is contended that more attention needs to be focused on the communication network in the study of health communication and on the role of mass communication in general. (KS)