**6.1 Changing knowledge and awareness**

Changing behaviour is the highest priority in any public health campaign, however, most of the mass media will change knowledge and awareness more easily than behaviour.

Theoretically, the mass media are supposed to be most effective in achieving awareness. This review supports that expectation. When measuring awareness as simple recognition of the message, up to 83% levels of awareness have been reported, with a median of 48%. Although, without a pre message measure, some of this (perhaps up to 9%) may be measurement error, e.g., a desire to please the interviewer.

Ceiling effects must also be considered. If awareness is moderately high before the campaign, there are ceilings on the increases possible and probably these increases are harder to achieve. If both pre and post levels of awareness are available, increases can be calculated based on the percent of audience possible to change. For example, if awareness of the seriousness of colon cancer was 11% prior to a campaign and 40% after it, the increase, instead of being 29% would be 29% of the possible change of 89% which is 33%.

Knowledge gain is clearly achievable using mass mediated health campaigns. When exposure is guaranteed, dramatic increases in knowledge (as large as 60%) have been observed. When exposure is not guaranteed but the campaign can saturate a community, knowledge gains around 25% seem feasible. The size of these knowledge gains decrease when the campaigns are national in scope and must compete with numerous other stimuli. Still, most of the campaigns were successful in achieving some knowledge gain, although around 10% appears to be a more achievable increase. Multi—channel campaigns appear to be much more successful than single channel, especially print only campaigns.

Below there is some evidence about changes in levels of knowledge and awareness during mass media public health campaigns:

Alcohol


#### HIV/AIDS

 Changes in levels of tolerance: those in the general public who say that homosexual relations are always or mostly wrong – 74% in 1987; 44% in 1997

The Role of Mass Media Communication in Public Health 411

given the wide reach of mass media. Such impact can only be achieved, however, if

There is renewed interest in the possibility of achieving policy goals through behaviour change. For example, a recent report commissioned for the Cabinet Office (Halpern and Bates, 2004) states that: 'Behaviourally based interventions can be significantly more costeffective than traditional service delivery.' Interventions to change health-related behaviour may range from a simple, face-to-face consultation between professional and patient to a complex programme, often involving the use of mass media. This briefing looks first at the evidence on the effectiveness of interventions in changing behaviour generally; and second







The evidence suggests that the following characteristics are the key elements for success in




Even though mass media health campaigns are used extensively, considerable debate continues over their effectiveness. This review differed from previous ones in that it included only those campaign evaluations that collected quantitative evidence of impact and it organized these data according to campaign objectives. In general, the results confirm Rogers and Storey's (1987) description of the era of moderate effects. As McGuire's (1989) hierarchy of effects model would predict, the size of the effects were greater at the earlier steps, i.e., awareness, and knowledge than the later stages of attitude change, and behavior change.

implementing clean-air policies to decrease pollution and improve health



raising), or knowledge and awareness of services to help prevent risks

principles of effective campaign design are carefully followed.

A range of types of intervention aim to change 'risky' behaviours:

about the harm smoking does to skin and appearance

assertiveness skills to suggest that condoms be used




at the evidence concerning mass media campaigns.

self-examination

changing behaviour:

settings

public acceptance of breastfeeding

assessment or formative research



Folic acid


Immunisation – the Hib vaccine

Awareness of the Hib vaccine: 5% in 1992; 89% in 1993.

Skin cancer


Note

With complex interventions that are intended to work synergistically it is difficult to attribute impacts to particular intervention components. Also, factors external to interventions – particularly if they are about sensitive subjects – may add to or subtract from their impact.

#### **6.2 Changing attitudes and behaviours**

All but four of the 21 evaluations of these health communication campaigns showed significant attitude change. The actual amount of change varied considerably. These results suggest that if exposure is insured, considerable attitude change is possible. The greatest amount of change (+38% for an AIDS video shown in waiting rooms of STD clinics (Solomon & DeJong, 1986) a case of forced exposure. The ARTA campaign (Woods, Davis, & Stover, 1991) also demonstrated considerable attitude change, an average of 20% across five attitude items, however, it must be remembered that the ARTA camp has received unusually high exposure for a PSA campaign, and was only part of extensive media coverage of HIV/AIDS. Therefore, it is impossible to know how much of that change is attributable to the campaign itself. Some of the evaluations clearly suffered from ceiling effects and the results are difficult to interpret. The surveys measuring outcomes of one of the Cancer Prevention Awareness campaigns, for example, found pre—campaign levels of 90+% on some of the items leaving little room to measure change. In spite of more control over airing than the typical PSA, the single channel campaigns did not achieve as much attitude change.

Although behaviour is normally considered one of the most difficult objectives to achieve in mediated health campaigns, the campaigns reviewed here were quite successful. Only six of the 29 behavioral change campaigns identified failed to achieve some level of change. The average change reported was 13% should be noted that these results may be biased by the tendency toward not publishing non—significant findings.

The literature is beginning to amass evidence that targeted, well-executed health mass media campaigns can have small-to-moderate effects not only on health knowledge, beliefs, and attitudes, but on behaviours as well, which can translate into major public health impact

Attitudes to people with HIV infection: those who think people with AIDS have only

Sales of folic acid supplements and prescription rates – up 50% in an eight-month

Proportion of the public who thought a suntan was important –28% in 1995; 25% in

Proportion of people who say they use a sunscreen when sunbathing in this country –

With complex interventions that are intended to work synergistically it is difficult to attribute impacts to particular intervention components. Also, factors external to interventions – particularly if they are about sensitive subjects – may add to or subtract from

All but four of the 21 evaluations of these health communication campaigns showed significant attitude change. The actual amount of change varied considerably. These results suggest that if exposure is insured, considerable attitude change is possible. The greatest amount of change (+38% for an AIDS video shown in waiting rooms of STD clinics (Solomon & DeJong, 1986) a case of forced exposure. The ARTA campaign (Woods, Davis, & Stover, 1991) also demonstrated considerable attitude change, an average of 20% across five attitude items, however, it must be remembered that the ARTA camp has received unusually high exposure for a PSA campaign, and was only part of extensive media coverage of HIV/AIDS. Therefore, it is impossible to know how much of that change is attributable to the campaign itself. Some of the evaluations clearly suffered from ceiling effects and the results are difficult to interpret. The surveys measuring outcomes of one of the Cancer Prevention Awareness campaigns, for example, found pre—campaign levels of 90+% on some of the items leaving little room to measure change. In spite of more control over airing than the typical PSA, the

Although behaviour is normally considered one of the most difficult objectives to achieve in mediated health campaigns, the campaigns reviewed here were quite successful. Only six of the 29 behavioral change campaigns identified failed to achieve some level of change. The average change reported was 13% should be noted that these results may be biased by the

The literature is beginning to amass evidence that targeted, well-executed health mass media campaigns can have small-to-moderate effects not only on health knowledge, beliefs, and attitudes, but on behaviours as well, which can translate into major public health impact

themselves to blame – 57% in 1987; 36% in 1996

Folic acid

period.

Skin cancer

1996

their impact.

Note

Immunisation – the Hib vaccine

34% in 1995; 41% in 1996.

**6.2 Changing attitudes and behaviours** 

Belief that a condom protects against HIV: 66% in 1986; 95% in 1997

Spontaneous awareness of folic acid – 9% in 1995; 39% in 1997

Awareness of the Hib vaccine: 5% in 1992; 89% in 1993.

single channel campaigns did not achieve as much attitude change.

tendency toward not publishing non—significant findings.

Women aged 18–19 whose partners used condoms: 6% in 1986; 22% in 1993.

given the wide reach of mass media. Such impact can only be achieved, however, if principles of effective campaign design are carefully followed.

There is renewed interest in the possibility of achieving policy goals through behaviour change. For example, a recent report commissioned for the Cabinet Office (Halpern and Bates, 2004) states that: 'Behaviourally based interventions can be significantly more costeffective than traditional service delivery.' Interventions to change health-related behaviour may range from a simple, face-to-face consultation between professional and patient to a complex programme, often involving the use of mass media. This briefing looks first at the evidence on the effectiveness of interventions in changing behaviour generally; and second at the evidence concerning mass media campaigns.

A range of types of intervention aim to change 'risky' behaviours:


The evidence suggests that the following characteristics are the key elements for success in changing behaviour:


Even though mass media health campaigns are used extensively, considerable debate continues over their effectiveness. This review differed from previous ones in that it included only those campaign evaluations that collected quantitative evidence of impact and it organized these data according to campaign objectives. In general, the results confirm Rogers and Storey's (1987) description of the era of moderate effects. As McGuire's (1989) hierarchy of effects model would predict, the size of the effects were greater at the earlier steps, i.e., awareness, and knowledge than the later stages of attitude change, and behavior change.

The Role of Mass Media Communication in Public Health 413

6. When accompanying back-up can be provided on the ground. Regardless of whether media alone are sufficient to influence health behaviour, it is clear that the success of

8. When a generous budget exists. Paid advertising, especially on television, can be very expensive. Even media with limited reach, such as pamphlets and posters, can be expensive depending on the quality and quantity. For media to be considered as a strategy in health promotion, careful consideration of costs and benefits needs to be

9. When the behavioural goal is simple. Although complex behaviour change such as smoking cessation or exercise adoption may be initiated through media programmes, the nature of media is such that simple behaviour changes such as immunisation or cholesterol testing are more easily stimulated through the media. In general, the more complex the behaviour change, the more back-up is required to supplement a media

10. When the agenda includes public relations. Many, if not most, health promotion programmes have an agenda which is not always explicit – maybe to gain public support or acknowledgement, to solicit political favour, or to raise funds for further programmes. Where public relations are either an explicit or implicit goal of a

1. *Evaluating message content effects:* What is the relative effectiveness and cost-effectiveness of various campaign themes (e.g., law enforcement, legal penalties, social stigma, guilt, injury to self and others) for reducing unhealthy behaviours? For influencing public

2. *Evaluating message delivery effects:* What is the dose–response curve for varying levels of advertising exposure (e.g., none, light, moderate, and heavy)? Does the shape of this curve vary according to message content and the outcome evaluated? What is the relative effectiveness and cost-effectiveness of different media types (TV, radio, etc.)? Paid advertising and public service announcements? What is the optimal exposure schedule for public health mass media campaigns (e.g., intermittent waves of messages vs a steady flow)? How should mass media campaigns be adapted to the changing media environment (e.g., market segmentation, Internet, message filtering devices)? 3. *Evaluating message/recipient interactions:* To what extent are certain population groups more or less likely to be influenced by mass media campaigns? Are some themes more likely than others to influence "hard-to-reach" target groups (e.g., enforcement themes

4. *Improving research design:* What measurement issues need to be addressed to improve assessment of media and message exposure? What research designs can best address

Brown, J. & Campbell, E. (1991). Risk communication: Some underlying principles. *Journal of* 

programme, mass media are effective because of their wide-ranging exposure.

media will be improved with the support of back-up programmes and services. 7. When long-term follow-up is possible. Most changes in health behaviour require constant reinforcement. Media programmes are most effective where the opportunity exists for long-term follow-up. This can take the form of short bursts of media activity

over an extended period, or follow-up activities unrelated to media.

undertaken.

health programme.

**8.2 Further research questions** 

support for stronger prevention activities?

for "hard-core" drinking drivers)?

problems in measuring exposure?

*Environmental Studies*, Vol. 38, 1991, 297-303.

**9. References** 
