A practical guide to implementing a successful social media recruitment strategy: lessons from the Eczema Monitoring Online trial

Participant recruitment into clinical trials remains challenging. The global increase in the number of social media users has accelerated the use of social media as a modality of recruitment, particularly during the COVID-19 pandemic when traditional recruitment methods were reduced. However, there is limited evidence on the performance of social media recruitment strategies into eczema clinical trials.

From September 2021 to January 2022, we recruited participants with eczema into an online randomised controlled trial using free advertising on Twitter, Facebook, Instagram and Reddit (unpaid methods), followed by paid Facebook advertisements (paid method). Unpaid methods were used periodically for 63 days, whilst the paid method for 16 days. Interested individuals who clicked on the advertisement link were directed to the study website, where they could sign up to participate. Consenting, randomisation and data collection occurred exclusively online, using a database management web platform. Evaluation of the social media recruitment methods was performed, including the number of expression of interests, enrolment yield, cost, baseline characteristics and retention.

Our multi-platform based social media recruitment strategy resulted in 400 expressions of interests, leading to 296 participants. Unpaid methods accounted for 136 (45.9%) of participants, incurring no financial cost. Paid Facebook adverts reached 154,370 individuals, resulting in 123 (41.6%) trial participants for a total cost of £259.93 (£2.11 per participant) and other recruitment methods resulted in 37 (12.5%) enrolments. Paid advertisements predominantly attracted younger participants below the age of 20, whereas unpaid methods mainly drew in participants between 20–29 years of age. The social media platforms recruited an ethnically diverse participant population. Completion rate of follow-up was slightly higher for the paid method (n = 103, 83.7%) compared with the unpaid methods (n = 111, 81.6%).

Unpaid social media posts recruited the most participants; however, it was time consuming for the researcher. Paid Facebook adverts rapidly recruited a large number of participants for a low cost and provided flexibility to target specific audiences. Our findings indicate that social media is an efficient tool that can potentially support recruitment to clinical trials.

ISRCTN45167024. Registered on 29 June 2021.