Public health programs focused on health promotion and prevention are in the agenda of European countries but further attention and investments are needed to better understand the best way to make them successful [1,2].

Communicating a broad range of health messages to a wide variety of audiences is challenging and in this context the role of mass media (such as television, radio, newspapers, billboards, posters, leaflets) is fundamental [3].

Social marketing, that promote ideas, attitudes and behaviours to achieve goals for social good trough the marketing principles and techniques, often use mass media tools to communicate [4]. Nevertheless, use and effectiveness of media in programs promoting healthy behaviours are not well defined.

The increasing fragmentation and cluttering of media environment and the opposing messages, the persuasive marketing for competing products and power of social norms, make difficult to evaluate its independent effects.

Recently only two reviews on mass media and health promotion were published. Clar et al. [5] mapped the existing research in the area of digital media use in public health and investigated the interdisciplinary aspects of quality and ethics that could contribute to this field on the basis of studies published between the start of 2000 and the end of June 2013. Furthermore, Robinson et al. [6] conducted a systematic review (search period, January 1980–December 2009) to evaluate the effectiveness of health communication campaigns that use multiple channels, including mass media, and distribute health-related products.

The aim of this literature review is to assess the use of mass media in health promotion programs and to point out the strengths and the weaknesses of available experiences. The research will provide recommendations for further health promotion campaigns by evaluating their impact on population throughout outcomes in Knowledge, Attitude and Practice (KAP) [7].

The review was carried out according to the recommendations of literature review methodology by Pautasso [8]. Publications in English were identified through searches of medical and scientific electronic databases using the following keywords combination: social marketing/ media/health. The syntax was as follows:

- (“social marketing” OR (“social” AND “marketing”) OR “social marketing”) AND “media” for medical databases: MEDLINE (PubMed), CINAHL, COCHRANE CCTR (Central Register of Controlled Trials), EPPI-CENTRE TRoPHI (The Trials Register of Promoting Health Interventions), TRIP Database.

- (“social marketing” OR (“social” AND “marketing”) OR “social marketing”) AND “media” AND “health” for general scientific databases: SCOPUS (the search was limited to social sciences, psychology, art and humanities, neurosciences and multidisciplinary) and WEB OF SCIENCE (the search was limited to healthcare science services, psychology, communication, sociology, behavioural sciences, social issues, social sciences, telecommunication).

It was chosen not to limit publication status. Searches were updated to 1st September 2014.

Inclusion and exclusion criteria were defined focusing on health promoting campaigns using mass media (such as television, radio, newspapers, billboards, posters, leaflets) that, not being interpersonal channels of communication, have the potential to reach a large portion of the community and do not depend on person-to-person contact [3,9]. In developed countries mass media are among the tools used in programs aimed at influencing health knowledge, attitudes and behaviours of a large proportion of the population.

Exclusion criteria were

• link to commerce: studying consumers preferences/behaviour, influencing the purchase of products/services (even if health related), promoting professionals private practices (even if healthcare activities);

• focus on one phase of a campaign only (pilot, planning, evaluation studies, experiments).

• education of healthcare professionals

• focus on the social system (i.e. family planning), environment, agriculture, medical tourism, civic education;

• focus on clinical topics (i.e. care, therapies, organ donation);

• presentation of qualitative data

• combined impact of multiple strategies without establishing the independent role and/or the unique effect of mass media components (data that cannot be identified);

• using an interpersonal approach (face to face contact, or telephonic conversation, focus group, peer-delivered education, peer-led activities, community health activities, family support, info points, stands, clinic visits) and/or not considering media as tools reaching a large number of people independently of person to person contact;

• focus on minority populations or ethnic subgroups (i.e. indigenous, aborigines) with cultures different from the western one.

Documents were selected first by reading the titles and available abstracts and then by text analysis. Duplicates and papers, that did not meet the inclusion criteria, were not considered. Finally, 50 programs were included in the review.

The 50 programs, reporting quantitative data, were explored and classified according to:

- Media tool (technologies and methodologies): print (i.e. book/ article, leaflet/brochure, billboard/posters, gadgets and all printed material), radio (i.e. cd, radio spot), television (i.e. TV film/movie/ video/spot, display), computer (i.e. CD ROM, WEB-site, social networks), and their possible combinations. The “Media combination” category was used to include programs using more than one media.

- Health topic: tobacco control (i.e. smoking cessation and decrease), substance misuse (i.e. alcohol, drugs, doping), sexual health (i.e. HIV, Chlamydia), physical activity, chronic diseases (i.e. asthma, low back pain), mental health (i.e. depression, sexual abuse), cancer (i.e. breast, skin), obesity and overweight, and vaccinations. Programs that were not enough to constitute a separate category were included in the “other topics” category.

- Target age group: children (0-12 years), adolescents (13-18 years), adults (19-64 years), aged (> 65 years). The “Multi target” category was used to include programs targeting more than one age group or when the target was not specified.

- Program duration: days (< 7 days), weeks (≥ 7 days - < 4 weeks), months (≥ 4 weeks - <12 months), years (≥1 year), not specified;

- Outcome categories: Knowledge (campaign and/or message awareness, comprehension, remembering, recall), Attitude (reactions, beliefs, intentions, motivations) and Practice (behaviour change, health outcomes, impact) [7].

Studies were classified effective if the authors reported a statistically significant improvement in some of the KAP outcome indicators in the article, while they were categorized not effective if in the results authors reported no significant p-value for none outcome indicators or they did not calculate it.

Data analysis was performed using the statistical software SPSS, version 20 and the Chi-square test. Statistical significance was defined as p≤0.05.

Databases search collected 10571 publications. Due to the amount of data identified, two reviewers excluded studies by detecting the first exclusion criterion reported in the publication abstracts. After this analysis 50 studies were identified.

Table 1 shows the distribution of programs and effective programs (presenting at least one significant improvement in the chosen outcome indicators - KAP) by topic, media and target.

Table 1: Distributions of programs and of effective ones (presence of at least one chosen indicator significantly improved) by topic, media, target.

All the programs were focused only on one health topic. Other topics include obesity and overweight (8%, 4/50), cancer (6%, 3/50), chronic diseases (4%, 2/50), mental health (4%, 2/50), and vaccinations (2%, 1/50).

A single media was used in the majority of the programs (58%, 29/50), while 26% (13/50) of the campaigns adopted an approach based on a mix of media: print+TV (8%, 4/50), print+radio+TV (8%, 4/50), print+radio (4%, 2/50), radio+TV (4%, 2/50), print+TV+PC (2%, 1/50).

Sixty eight percent (34/50) of campaigns were directed to a single age group. Thirty two percent (16/50) of programs addressed two or more age groups: adults+aged (12%, 6/50), adolescents+adults+aged (6%, 3/50), adolescents+adults (4%, 2/50), children+adults (2%, 1/50), in the 8% (4/50) the target was not specified.

Most campaigns lasted months (46%, 23/50) or years (38%, 19/50) whereas short term campaigns (with a duration < 4 weeks) were rarely used: 6% (3/50) lasted weeks and 6% (3/50) days. Two studies did not specify the period of the campaign.

Thirty four out of 50 programs (68%) reported at least one statistically significant improvement in the chosen outcome indicators. Sixty two percent (31/50) of the studies evaluated the program impact on knowledge and 32.2% (10/31) reported at least one statistically significant improvement. Among them, 83.9% (26/31) measured campaign awareness [15.4% (4/26) were effective]; and 51.6 (16/31) measured message awareness [37.5% (6/16) were effective]. Fifty six percent (28/50) of the studies evaluated the program impact on attitude and 50% (14/28) reported at least one statistically significant improvement. Among them, 39.3% (11/28) measured reaction change [45.5% (5/11) of them were effective]; 46.4% (13/28) belief change [53.8% (7/13) were effective]; and 71.4% (20/28) intention change [50% (10/20) were effective].

Sixty four percent (32/50) of the studies evaluated the program impact on practice and 68.7% (22/32) reported at least one statistically significant improvement. Among them, 93.8% (30/32) measured behavior change [70% (21/30) were effective]; and 21.9% (7/32) measured health outcomes [42.8% (3/7) were effective]. Two studies measured the intervention impact but no statistically significant results were found

Greater effectiveness can be seen in programs related to substances misuse (73.3%, 11/15) and tobacco control (58.3%, 14/24), in computerbased interventions (92.3%, 12/13) and in campaigns targeting adolescents (75%, 12/16) and adults (52.6%, 20/38). Table 2 shows the distribution of indicators with a statistically significant improvement according to outcome categories by topic, media and target.

Table 2: Distribution of indicators with statistically significant improvement (presence of at least one chosen indicator significantly improved) according to outcome categories by topic, media and target.

A short description of the chosen indicators in the 50 selected programs is summarized in Table 3.1 and Table 3.2, according to target, media used and outcome broad categories.

Table 3.1: Review evidences by intended audiences, media type, and outcomes.

Table 3.2: Review evidences by intended audiences, media type, and outcomes.

Despite the long period considered by the literature review (from 2000-2014) the experiences on the use of mass media in health promotion and prevention, reported as a scientific paper evaluating the outcomes, are few: 50 in fourteen years. The review highlighted the difficulty of comparing the studies and their results, due to the great variability of media used, intended audiences, methods adopted to implement the programs and to measure their results, and the small number of experiences for each topic. Nevertheless, to find clear evidences from the sum of health promotion and prevention programs using mass media is arduous.

In this literature review following evidences emerge:

Media tool

Television was the most used media tool in health promotion and prevention programs whereas the computer was the most effective, especially among adolescents. These findings confirm the literature reporting that a message combining different techniques (text, audio, still images, animation, video, or interactivity content forms) seems to be associated with greater success in health promotion programs [59].

Health topic

The reviewed studies focused on topics widely recognized as priorities in all countries [2], such as smoke, substance misuse, physical activity and sexual health. However, only few papers reported emerging health problems such as cancer, chronic diseases, mental health, vaccinations, although they have large impact on public health [1] and could be addressed by mass media tools [9]. Tobacco control was the more frequent topic in the analyzed campaigns. This could be due to the fact that smoking is the leading preventable cause of illness and premature death in the world [60]. Programs for tobacco control had an impact on attitudes (e.g. smoking intention and motivation) among adolescents and adults [16,20,22,25,31,33,43]. An impact was also found on behaviors such as smoking cessation and abstinence from tobacco among adolescents and adults [16,25,26,40,43,46]. A television campaign obtained an increase in the number of calls to an antismoking telephone, but the intended audience was not specified [55]. Among the programs on preventing substance misuse, alcohol campaigns were known among adults [11,32]. A computerbased campaign was successful in decreasing alcohol consumption in adolescents [44], whereas another one, using a mix of mass media (print, radio and television) and targeting adults, was effective both in reducing alcohol use and in driving after drinking. The same campaign also reduced alcohol related crashes [32]. A radio and television-based program was effective in decreasing the use of marijuana among adolescents [45]. Programs promoting physical activity were effective in increasing knowledge about physical activity and practice among children [48] and in increasing the beliefs on advantages of physical activity and the intentions to get physical exercises in adolescents and adults [53] A campaign based on a mix of media increased physical activity in adults [35]. Sexual health campaigns focused on HIV, sex safety and sexual abuse. Computer-based programs increased, among adolescents, the awareness about HIV, the good opinion on messages on condom use and the intention to wait to have sex [42]. Other campaigns on sexual education improved knowledge on HIV and beliefs in safe sex among adults [23] and increased the number of Chlamydia tests among adolescents and adults [57]. Two campaigns were successful in preventing cancer skin by increasing sun protection use, limiting sun exposure and decreasing sunburns [54-56]. In the field of chronic diseases, the program on asthma did not increase knowledge about asthma symptoms among adolescents, even if campaigns were known [10]. In the field of mental health there was only a campaign that increased knowledge in depression symptoms and treatments among adolescents [38]. A program delivered through print materials obtained an increase of flu vaccinations rates among adults and elders [14].

Target age group

Regarding the intended audience, adults and adolescents were the most frequently involved groups in the campaigns, whereas in the one third of cases, programs were addressed to different age classes of population at the same time. These data are not in accordance with the literature reporting that new generations (6-18 years) are the recommended target in primary prevention because children and young people are more exposed to media, more receptive to environmental stimulus and more adaptable to change than adults [61,62].

Program duration

Effectiveness of long lasting (months or years) campaigns was similar to shorter (weeks) campaigns.

Outcome

The main goal of prevention programs is promoting healthy behaviors. The review showed that 69% of the considered programs persuaded people to change their behaviors, 32% of campaigns modified knowledge and 50% of them revised attitudes in intended audience. This confirms that mass media campaigns could produce positive changes or prevent negative changes in health-related behaviors in society [3].

This review highlights both the large impact that mass media could have on health-related knowledge/attitudes/behaviors and the difficulty to find some definitive conclusions about mass media use in health promotion programs due to the heterogeneity of the existing campaigns.

However, data provide a general overview of the available published literature on health promotion through mass media that could be used as a starting point to develop new programs. In fact, to establish the effectiveness of mass media, it is necessary to collect/carry out and compare an adequate number of studies testing the surveyed media, separately from other media, targeting the same well defined audience and evaluating the same goals.

Next studies should address important public health issues that have not been adequately considered up to now, such as cancer, chronic diseases, mental health, and vaccinations. The fact that the computer resulted the most effective media calls for further experiments on computer/web-based communication to convey health information.

The study was performed without external support or funding. Preliminary results have been presented as poster at the 6th European Public Health Conference (Brussel, 13-16 November 2013).

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