Background: Developed and launched in Victoria in October 2018, the 13 Cancers mass media campaign, aimed to highlight the link between being above a healthy weight and increased risk of thirteen types of cancer, and to motivate Victorians to avoid sugary drinks to help achieve or maintain a healthy weight. The primary aim of the evaluation was to measure campaign awareness and determine campaign impact on knowledge and behaviour pertaining to sugary drink consumption, weight gain and cancer risk.
Methods: The evaluation used a controlled cohort design. Pre-campaign telephone surveys of adults aged 25 to 59 years were undertaken in the campaign state (Victoria, N=850) and non-campaign states (all other states combined except WA, N=850) using a landline/mobile sampling frame, with 72% of these respondents surveyed post-campaign (N=1,220). Multivariable logistic regression models accounting for repeated measures were tested.
Results: Almost half of Victorians (47%) were aware of the campaign, with 26% recalling the campaign unprompted and 21% recognising the campaign when prompted. Victorians with obese BMI (>30) were significantly more likely to be aware of the campaign than Victorians not overweight (BMI <25). Knowledge of the link between overweight and cancer increased at follow-up among Victorians who were regular sugary drink consumers with BMI 25+. Sugary drink consumption at baseline was significantly lower in Victoria than the non-campaign states and did not further reduce following the campaign. However, intentions to drink less fruit drink, energy drinks, and flavoured milk drinks increased among key respondent groups in Victoria following the campaign. Victorians’ support for taxing sugary drinks also increased post-campaign.
Conclusions: Findings provide evidence of the utility of a healthy weight and lifestyle mass media campaign to influence knowledge and behavioural intentions regarding sugary drink consumption, unhealthy weight and cancer risk.