Sophisticated societies are dependent on mass media to deliver health information. Marshall McLuhan calls media "extensions of man." G. L. Kreps and B. C. Thornton believe media extend "people's ability to communicate, to speak to others far away, to hear messages, and to see images that would be unavailable without media" (1992, p. 144).
It follows that employment of mass media to disseminate health news (or other matters) has, in effect, reduced the world's size. The value of health news is related to what gets reported and how it gets reported. According to Ray Moynihan and colleagues:
The news media are an important source of information about health and medical therapies, and there is widespread interest in the quality of reporting. Previous studies have identified inaccurate coverage of published scientific papers, overstatement of adverse effects or risks, and evidence of sensationalism. The media can also have a positive public health role, as they did in communicating simple warnings about the connection between Reye's syndrome and the use of aspirin in children (1999, p. 1645).
Despite the potential of news media to perform valuable health-education functions, Moynihan et al. conclude that media stories about medications continue to be incomplete in their coverage of benefits, risks, and costs of drugs, as well as in reporting financial ties between clinical trial investigators and pharmaceutical manufacturers.
The mass media are capable of facilitating short-term, intermediate-term, and long-term effects on audiences. Short-term objectives include exposing audiences to health concepts; creating awareness and knowledge; altering outdated or incorrect knowledge; and enhancing audience recall of particular advertisements or public service announcements (PSAs), promotions, or program names. Intermediate-term objectives include all of the above, as well as changes in attitudes, behaviors, and perceptions of social norms. Finally, long-term objectives incorporate all of the aforementioned tasks, in addition to focused restructuring of perceived social norms, and maintenance of behavior change. Evidence of achieving these three tiers of objectives is useful in evaluating the effectiveness of mass media.
Mass media performs three key functions: educating, shaping public relations, and advocating for a particular policy or point of view. As education tools, media not only impart knowledge, but can be part of larger efforts (e.g., social marketing) to promote actions having social utility. As public relations tools, media assist organizations in achieving credibility and respect among public health opinion leaders, stakeholders, and other gatekeepers. Finally, as advocacy tools, mass media assist leaders in setting a policy agenda, shaping debates about controversial issues, and gaining support for particular viewpoints.
Television. Television is a powerful medium for appealing to mass audiencest reaches people regardless of age, sex, income, or educational level. In addition, television offers sight and sound, and it makes dramatic and lifelike representations of people and products. Focused TV coverage of public health has been largely limited to crises. However, for audiences of the late 1950s, the 1960s, and the 1970s, television presented or reinforced certain health messages through product marketing. Some of these messages were related to toothpaste, hand soaps, multiple vitamins, fortified breakfast cereals, and other items.
Public health authorities have expressed concern about the indirect influence of television in promoting false norms about acts of violence, drinking, smoking, and sexual behavior. A hypothetical equation for viewers might be: drinking plus smoking equals sex and a good time. Safe sex practices are rarely portrayed on television. An additional public health concern is that TV viewing promotes sedentariness in a population already known for its multiple risk factors for cardiovascular disease and other chronic illnesses.
A more focused coverage of health matters occurred in the 1990s as a result of two events: (1) an expansion of "health segments" on news broadcasts, which included the hiring of "health" reporters, and (2) the expansion and wider distribution of cable television (CATV) and satellite systems. Television coverage of health issues reveals some of the medium's weaknesses as an educator, however. Health segments incorporated into news broadcasts are typically one to three minutes in lengthhe consumer receives only a brief report or "sound bite," while the broadcaster remains constrained by the fact that viewers expect the medium to be both visual and entertaining. Fortunately, with the advent and maturation of CATV, more selected audience targeting has become possible. The Health Network is dedicated entirely to health matters, while other cable networks (e.g., Discovery Channel) devote significant amounts of broadcast time to health. This narrowcasting allows the medium to reach particular market segments. However, the proliferation of cable channels decreases the volume of viewers for a given channel at any point in time. According to George and Michael Belch, even networks such as CNN, ESPN, and MTV draw only 1 to 2 percent of primetime viewers.
Although TV has the potential to deliver messages about HIV/AIDS (human immunodeficiency virus/acquired immunodeficiency syndrome), smoking, cardiovascular disease, cancer, and so on, televised messages have the characteristic of low audience involvement. The main consumer effect of messages occurs through repetition and brand familiarity. Most health messages do not have the exposure level that brands of toothpaste, soap, or antiperspirant receive, for public health groups rarely can sustain the cost of television, thereby limiting their message's penetration.
For all its potential strengths, TV suffers many shortcomings. The cost of placing health messages on TV is high, not only because of the expense of purchasing airtime, but because of production time for PSA creation. Televised messages are fleetingiring in most instances for only 15 to 30 seconds. Belch and Belch point out that for 13 to 17 minutes of every hour viewers are bombarded with messages, creating a clutter that makes retention difficult.
Radio. Radio also reaches mass and diverse audiences. The specialization of radio stations by listener age, taste, and even gender permits more selectivity in reaching audience segments. Since placement and production costs are less for radio than for TV, radio is able to convey public health messages in greater detail. Thus, radio is sometimes considered to be more efficient.
Radio requires somewhat greater audience involvement than television, creating the need for more mental imagery, or what Belch and Belch call "image transfer." Because of this, radio can reinforce complementary messages portrayed in parallel fashion on TV. However, the large number of radio stations may fragment the audience for health message delivery.
Radio health message campaigns have been effective in developing countries, especially when combined with posters and other mass media. Ronny Adhikarya showed that mass media message targeted at wheat farmers in Bangladesh increased the percentage of those who carried out rat control from 10 percent to 32 percent in 1983. Continuation of the campaign in subsequent years saw rat control efforts rise to 72 percent.
Internet. The advent of the World Wide Web and the massive increase in Internet users offers public health personnel enormous opportunities and challenges. The Internet places users in firmer autonomous control of which messages are accessed and when they are accessed. It is possible to put virtually anything on-line and disseminate it to any location having Internet access, but the user has little control over quality and accuracy. Internet search engines can direct users to tens of thousands of web sites after the user's introduction of one or more keywords. A critical task for public health educators will be to assist people in discriminating among Internet health-information sources. Efforts need to stop short of censorship, thus balancing accuracy, quality, and (in the U.S.) protection of free speech (First Amendment rights).
Unlike TV or radio, which are available in nearly all households, Internet access requires some technical skill, as well as the resources to purchase hardware and Internet subscription services. J. R. Finnegan and K. Viswanath explain that, as with its predecessor technologies, the Internet suffers from a certain "legacy of fear" about its impact on children, youth, and others. As with cinema since the 1940s and TV since the 1950s, the Internet has been accused of promoting mindlessness; exposing people to pornography, violence, and other examples of society's lowest common denominators; and enabling sedentary behavior. The Internet is said to facilitate activities of society's hate groups and to teach children and others how to construct bombs and obtain weapons. Unlike some other mass media, the Internet is presently not universally available across socioeconomic strata due to cost and other barriers. It is possible that this lack of universality has already contributed to existing information gaps between society's "haves" and "have-nots."
The Internet's utility for conveying health information can be illustrated by looking at three sample web sites. Considered by some to be the best source for public health data and information is the web site of the Centers for Disease Control and Prevention (http://www.cdc.gov). From here persons can locate numerous government data sources, obtain facts on chronic and infectious diseases, and gain fingertip access to health updates, including the Morbidity and Mortality Weekly Report (MMWR). Another valuable site is that of the Association for Toxic Substances and Disease Registry (http://www.atsdr.cdc.gov/HEC/primer.html), which includes a primer on health risk communication principles and practice. Through this site, persons learn how to communicate about health risks to a skeptical public, including factors that influence the public's risk perceptions. Finally, Columbia University's health education web site (http://www.goaskalice.columbia.edu) makes it possible to access information on a voluminous array of health topics, with particular relevance to college students. This site also permits individuals to submit questions anonymously, receive responses, and be referred to other Internet links. These items are then archived for use by persons having similar queries.
Speculating about the Internet's future is not easy. However, the Internet offers all of the audio and visual strengths of other electronic media, plus interactivity and frequent updates. The challenge is to increase its availability and augment the skills of Internet users.
Newspapers. Belch and Belch estimate that newspapers are read daily in 70 percent of U.S. households, and in as many as 90 percent of high-income households. Newspapers permit a level of detail in health reporting not feasible with broadcast media. Whereas one can miss a television broadcast about breast cancer, and thus, lose its entire message, one can read the same (and more detailed) message in a newspaper at one's choice of time and venue. Although newspapers permit consumers flexibility concerning what is read, and when, they do have a brief shelf life. In many households, newspapers seldom survive more than one or two days.
Newspapers are available in daily and weekly formats, and local, regional, and national publications exist. In addition, there are numerous special audience newspapers (e.g., various ethnic groups, women and feminist related, gay and lesbian, geography-specific, neighborhood). Consequently, health messages contained in newspapers can reach many people and diverse groups. Newspapers often fall short of their dissemination potential, however. In addition to educating people about public health, deliberate efforts need to be directed at educating other media and politicians (McDermott 2000, p. 269).
Other authorities have illustrated the shortcomings of the newspapers in conveying health information. Few stories call for individual or community policy or action, and even fewer present a local angle.
Magazines. Belch and Belch divide magazines into three varieties: consumer (e.g., Reader's Digest, Newsweek, People), farm (e.g., Farm Journal, National Hog Farmer, Beef), and business (professional, industrial, trade, and general business publications). Magazines have several strengths, including audience selectivity, reproduction quality, prestige, and reader loyalty. Furthermore, magazines have a relatively long shelf lifehey may be saved for weeks or months, and are frequently reread, and passed on to others. Magazine reading also tends to occur at a less hurried pace than newspaper reading. Health messages, therefore, can receive repeated exposure.
Other Print Media. Pamphlets, brochures, and posters constitute other print media used to disseminate health messages. These devices are readily found in most public health agencies, offices of private practitioners, health care institutions, and voluntary health organizations. They are common and familiar educational tools of the American Cancer Society, the American Heart Association, and the American Lung Association. Though widely used, their actual utility is infrequently evaluated (e.g., units distributed vs. changes in awareness, cost analysis). Until the 1990s, few of these print media were developed with the assistance of target audiences, and few contained varied messages, were culturally tailored, or employed readability and face validity techniques. The extent to which persons read, reread, and keep these devicesr circulate them to other readerss not well evaluated. Thus, their permanence is unknown.
Outdoor Media. Outdoor media include billboards and signs, placards inside and outside of commercial transportation modes, flying billboards (e.g., signs in tow of airplanes), blimps, and skywriting. Commercial advertisers such as Goodyear, Fuji, Budweiser, Pizza Hut, and Blockbuster all make extensive use of their logo-bearing blimps around sports stadiums. In the United States, none of these outdoor modes are used extensively to convey health messages, although billboards and transit placards are the most likely forms to contain health information. For persons who regularly pass by billboards or use public transportation, these media may provide repeated exposure to messages. Pro-health messages displayed on urban public transportation may suffer, however, from the image problems that afflict urban buses and subways. In addition, the effectiveness of such postings wears out quickly as audiences grow tired of their sameness.
Tobacco and alcohol manufacturers have made extensive use of billboards and other outdoor media. However, the 1998 Master Settlement Agreement between the states and the tobacco industries outlawed billboard advertising of cigarettes. In their 1994 Chicago-based study, Diana Hackbarth and her colleagues revealed how billboards promoting tobacco and alcohol were concentrated in poor neighborhoods. Similar themes were seen in other urban centers (Baltimore, Detroit, St. Louis, New Orleans, Washington, D.C., and San Francisco) where alcohol and tobacco billboards were much more concentrated in African-American neighborhoods than in white neighborhoods. The tobacco industry now pursues the same strategy in developing countries.
Decades of studies on the consequences of mass media exposure demonstrate that effects are varied and reciprocalhe media impact audiences and audiences also impact media by the intensity and frequency of their usage. The results of mass media for promoting social change, especially in developing countries, have become important for public health. J. R. Finnegan Jr. and K. Viswanath (1997) have identified three effects, or functions, of media: (1) the knowledge gap, (2) agenda setting, and (3) cultivation of shared public perceptions.
The Knowledge Gap. Health knowledge is differentially distributed in the population, resulting in knowledge gaps. Unfortunately, mass media are insufficient for distributing information in an egalitarian fashionhanges in social structure and institutions are also necessary for this to occur. Thus, the impact of mass media on audience knowledge gaps is influenced by such factors as the extent to which the content is appealing, the degree to which information channels are accessible and desirable, and the amount of social conflict and diversity there is in a community. Hence, public health media campaigns are more effective when structural factors that impede the distribution of knowledge are addressed.
Agenda Setting. The selective nature of what members of the media choose for public consumption influences how people think about health issues, and what they think about them. When Rudolph Giuliani, the mayor of New York City, publicly disclosed he had prostate cancer prior to the 2000 New York senatorial election, many news media reported the risks of prostate cancer, prompting greater public awareness about the incidence of the disease and the need for screening. A similar episode occurred in the mid-1970s when Betty Ford, wife of President Gerald R. Ford, and Happy Rockefeller, wife of Vice President Nelson Rockefeller, were both diagnosed with breast cancer.
A related theme is the extent to which the media set the public's perception of health risks. According to J. J. Davis, when risks are highlighted in the media, particularly in great detail, the extent of agenda setting is likely to be based on the degree to which a public sense of outrage and threat is provoked. Where mass media can be especially valuable is in the framing of issues. "Framing" means taking a leadership role in the organization of public discourse about an issue. Media, of course, are influenced by pressures to offer balance in coverage, and these pressures may come from persons and groups with particular political action and advocacy positions. According to Finnegan and Viswanath, "groups, institutions, and advocates compete to identify problems, to move them onto the public agenda, and to define the issues symbolically" (1997, p. 324). Thus, persons who desire to access mass media's agenda-setting potential must be aware of the competition.
Cultivation of Perceptions. Cultivation is the extent to which media exposure, over time, shapes audience perceptions. Television is a common experience, especially in the United States, and it serves as what S. W. Littlejohn calls a "homogenizing agent." However, the effect is often based on several conditions, particularly socioeconomic factors. Prolonged exposure to TV or movie violence may affect the extent to which people think community violence is a problem, though that belief is likely moderated by where they live. However, the actual determinants of people's impressions of violence are complex, and consensus in this area is lacking.