Supplementary Material for: What Can Twitter Tell Us about Skin Cancer Communication and Prevention on Social Media?

Background: Skin cancer places a substantial burden on the health system in Australia. The modernisation of skin cancer prevention interventions by using social media may enhance their contemporary reach and relevance, especially among the youth. This study aimed to analyse Twitter posts in Australia to establish a baseline of skin cancer and sun-related communication trends. Methods: Tweets posted over the summer of 2018/2019 relating to relevant keywords and hashtags such as “slipslopslap” and “sunscreen” were analysed using quantitative and qualitative methods. The number of tweets, related communication patterns, and possible factors for sudden changes in tweet volume were studied. Results: Results showed that Australians are using Twitter to communicate about their sun-related and skin cancer experiences and to share advice and information on this matter. Overall, Australians use Twitter more frequently to talk about sunscreen (number of tweets between December 2018 and February 2019 = 5,842) and/or skin cancer (n = 3,936), but not so often to communicate about other sun-protective behaviours (n = 1,972) or skin cancer prevention campaigns (n = 108). The number of tweets is greatly affected by the increase in temperature. Celebrities, non-health-related organisations with a high number of followers, and individuals sharing their own skin cancer experiences achieve a substantial number of likes and retweets and thus influence on Twitter regarding skin cancer-related communication. Conclusions: The results allow deeper understanding of important determinants for effective social media use for health promotion and public health messaging in the future. Linking tweets with temperature, sharing by celebrities or non-health-related organisations and individuals with a high following can all contribute to greater spread of skin cancer and sun-related messages.