1152Use of Facebook to recruit cohort study participants

Abstract Background Social media is a relatively new means to recruit research participants. Methods The Australian Breakthrough Cancer (ABC) Study is a prospective cohort study that recruited people aged 40-74 years over 2014-2018. A range of recruitment methods, including ‘traditional’ (e.g. print media, electoral roll, word of mouth) and newer methods (i.e. social media, particularly Facebook) were used. Here we describe and compare these methods of recruitment. Results 52,614 (66%) of ABC Study registrants indicated they had heard about the study via Facebook (36,672 clicked through from an advertisement for the study and 15,942 through users ‘sharing’ content). Overall, 51,586 (64%) participants (58% female, 42% male) completed baseline study components (online questionnaires and provided a DNA sample). 58% of Facebook registrants completed baseline components, compared with 75% of those recruited by traditional methods. The cost per acquisition using Facebook was $1.66 whereas the cost per acquisition using traditional methods (e.g. via the electoral roll) was up to $30. Facebook recruitment initially attracted more female registrants but targeted advertising dramatically increased the proportion of men. Conclusions Targeted advertising can be used to modify the types of respondents obtained via Facebook. Although the proportion completing baseline study components was lower than for traditional methods of recruitment, the cost per acquisition was cheaper making it feasible to recruit a larger number of participants to obtain the desired study size. Key messages Facebook is a viable and economical source of recruits to large prospective research studies.