P6.5 Effectiveness of Facebook For Participant Recruitment Into a Blood Pressure Randomised Controlled Clinical Trial

The cost of conventional advertising to recruit participants for clinical trials is expensive and can be ineffective. Social media may be a useful tool to improve participant recruitment. This study evaluated the use of Facebook advertising to recruit participants into a clinical trial. Conventional advertisements (newspaper, radio, posters in doctors clinics) were employed for the first 20 months of a clinical trial conducted in the Australian capital cities of Hobart, Brisbane and Canberra. With dwindling participant recruitment, a Facebook advertising campaign, targeting 18 to 69 year olds currently taking blood pressure medication was employed in each city. Campaigns were broadcast intermittently over a four month period, with recruitment results compared to those using conventional methods in the previous 20 months. Facebook advertisement resulted in a significant increase in the number of participants recruited per month among the Canberra and Hobart sites (from 4.1/month to 7.0/month; p<0.05). However, participant recruitment remained unchanged (and low) at the Brisbane site (2.4/month to 2.6/month; p = 0.89). Despite a greater population reach in Brisbane (n = 91,828) compared with Canberra (n = 71,343) and Hobart (n = 52,647), the number of clicks onto the advertisement in Brisbane was equal to other sites (n = 2757, n = 2521, n = 2991 respectively). Several attempts were made to improve the Facebook advertising strategy in Brisbane, but with no effect. Facebook advertisement can be a successful tool to increase participant recruitment into a blood pressure clinical trial, but effectiveness appears to be location-dependent.