Background: The mass media have been used as a way of delivering preventive health messages. They have the potential to reach and to modify the knowledge, attitudes and behaviour of a large proportion of the community.
Objectives: To evaluate the effectiveness of mass media interventions to prevent smoking in young people in terms of reduced smoking uptake, in addition to secondary outcomes including improved smoking outcomes, attitudes, behaviours, knowledge, self-efficacy and perception.
Search strategy: We searched the Cochrane Tobacco Addiction Group Specialised Register and conducted additional searches of MEDLINE and EMBASE in July 2010.
Selection criteria: Randomized trials, controlled trials without randomization and time series studies that assessed the effectiveness of mass media campaigns (defined as channels of communication such as television, radio, newspapers, bill boards, posters, leaflets or booklets intended to reach large numbers of people and which are not dependent on person to person contact) in influencing the smoking behaviour (either objective or self-reported) of young people under the age of 25 years.
Data collection and analysis: Information relating to the characteristics and the content of media interventions, participants, outcomes, methods of the study and risk of bias was abstracted by two independent reviewers. Studies were combined using qualitative narrative synthesis.
Main results: Seven out of a total of 84 studies reporting information about mass media smoking campaigns met all of the inclusion criteria. All seven studies used a controlled trial design. Three studies concluded that mass media reduced the smoking behaviour of young people. All of the effective campaigns had a solid theoretical basis, used formative research in designing the campaign messages, and message broadcast was of reasonable intensity over extensive periods of time.
Authors' conclusions: There is some evidence that mass media can prevent the uptake of smoking in young people, however the evidence is not strong and contains a number of methodological flaws.