THE RELATIONSHIP OF MASS MEDIA TO OTHER FORMS OF COMMUNICATION
The interaction between media messages and interpersonal communication was first described by Elihu Katz and Paul Lazarsfeld in their two-step flow hypothesis. They argued that media effects were moderated principally by interpersonal encounters. Community opinion leaders scan the media for information, then communicate that information to others in interpersonal contexts. It is in this second step, interpersonal interaction, that opinion leaders wield enormous power, influencing others not only by what they choose to reveal but also the slant that they use in conveying the message.
The two-step model has been expanded to include multistep modelsost notably information diffusion models. Step models have been limited by their linear assumptions of one-way influence and causation. Media influence is undeniably linked to complex interpersonal dynamics. A shared influence likely results when people are exposed to health messages and then converge together in contexts that influence what they say to one another (and even how they say it), as well as what they selectively think.
George Gerbner describes a three-component framework. The first of these components is semiotics, the study of signs, symbols, and codes. Language comprises one such set of symbols and codes that can be further embellished by sights, sounds, and other visual and aural cues. The second aspect of the framework relates to behaviors and interactions associated with exposure to messages. Psychologists, marketers, and others attempt to predict behavior based on specially designed messages. The third element examines how communication is organized around social systems, and the extent to which history and human experience influence society's institutions.
Designers of health messages need to consider such models and frameworks. Modern views of health behavior change acknowledge eclectic approaches and consider multiple aspects of human experience, from the individual level to the community level. Individual channels of communication (e.g., face-to-face encounters) offer personal support and may invoke trust, but are labor intensive, have limited reach, and may require ancillary materials. Mass media channels transmit information rapidly and to general or specific audiences. Mass media can set agendas, but questions have been raised concerning their impartiality and integrity. Community channels (e.g., coalitions, community action groups, and the like), have less "reach" than mass media, but they reinforce, expand, and localize media messages and offer institutional and social support. Knowledge of the complementary strengths of various channels helps to optimize penetration and effectiveness of health messages.
MASS MEDIA PUBLIC HEALTH CAMPAIGNSHE RIGHT "MIX"
Because of the inherent properties of various mass media, a U.S. Department of Health and Human Services publication advises that health-message designers consider a series of questions relative to choice of channels:
· Which channels are most appropriate for the health problem/issue and message?
· Which channels are most likely to be credible to and accessible by the target audience?
· Which channels fit the program purpose (e.g., inform, influence attitudes, change behavior)?
· Which and how many channels are feasible, considering your time and budget?
A 1999 article by A. G. Ramirez and colleagues describes a media mix that significantly increased adherence to recommended guidelines concerning cervical cancer screening among women in a predominantly Spanish-speaking Texas border city. The media mix included 82 television segments, 67 newspaper stories, and 48 radio programs, all featuring role models. In a 1998 study by Ramirez and other investigators, programs employing a similar strategy in New York, Florida, and California showed significant change in target behaviors among Hispanic populations.
In Project Northland, Cheryl Perry's team of researchers focused on moderating alcohol use by adolescents, but could not use radio and television spots due to their potential confounding properties (i.e., being heard or viewed by adolescents in a nonintervention comparison group) with respect to evaluation of this school-and community-based intervention. Print media, including posters, brochures, and newsletters, were used in the intervention communities to market health messages and advertise ancillary events, and adolescents and adults were trained in media advocacy to increase media coverage of underage use of alcohol.
The primary health communication tool used by the Centers for Disease Control and Prevention (CDC) is PRIZM, which was developed by Claritas, Inc. PRIZM divides the United States into sixty-two lifestyle clusters, or groups of people with similar "geodemographic characteristics, consumer behaviors, psychosocial beliefs, and media habits" (Parvanta and Freimuth 2000, p. 22). It provides data on 250 sociodemographic census variables and approximately 500 items concerning media preferences, purchasing behaviors, and lifestyle activities.
Following a needs assessment that revealed an abnormally high birth-defect rate in a four-county area of Virginia, mass media were tapped to inform more than 22,000 women of child-bearing age about the health benefits of folic acid supplements and folate-rich foods. The campaign included television and radio PSAs, brochures, posters and display boards, as well as the cooperation of a local grocery store chain that provided other print media (food information cards and special food labels on folate-dense products). In a 1999 evaluation, CDC investigators reported a statistically significant increase in folic acid awareness between 1997 and 1999.
Mass media have been major sources of information about HIV/AIDS and other sexually transmitted infections. In a 2000 study, 96 percent of 1,290 men aged twenty-two to twenty-six reported hearing about these subjects through television advertisements, radio, or magazines. Some authorities have expressed skepticism about the mass media's future motivation to provide positive sex education messages, since portrayal of sex attracts viewers, which in turn, increases revenues.
Other evidence of the media's ability to improve reproductive health and promote population control exists, especially from developing countries. Mass media have made people aware of modern contraception and where to access it, as well as linking family planning to other reproductive health care and to broader roles for women. Communication about family planning and population control creates awareness, increases knowledge, builds approval, and encourages healthful behaviors. In Egypt, where nearly all households have television, population control objectives have been achieved through televised PSAs. Data also support the positive effects of mass media messages on contraception use in Zimbabwe, Ghana, Nigeria, and Kenya. In a 1999 Tanzania-based study, a team of researchers led by Everett M. Rogers showed how the popularity of a radio soap opera promoting family planning increased listeners' self-efficacy with respect to discussing contraception with spouses and peers.
Although mass media are important for disseminating health messages and encouraging an adoption of healthful lifestyles, they currently fall short of their potential. The realization of this potential in the future depends, in part, on increasing the media advocacy skills of public health authorities, improving understanding of competing antihealth media messages, and organizing channels for an optimal media mix.