UC San Diego

Objective

Traditional nondigital methods of participant recruitment for clinical research studies in rheumatology can be costly and inefficient, particularly for recruitment of underserved populations. We aimed to address this need by evaluating two methods of online recruitment to an observational cohort of individuals at risk for rheumatoid arthritis, namely web and Facebook advertisements.

Methods

A 3-month countywide web-based recruitment campaign was conducted consisting of text and image-based advertisements. Similar advertisements were subsequently displayed on Facebook, initially in English for 5 months and later in Spanish for an additional 3 months. Individuals who clicked on advertisements were directed to a website landing page containing study information and could contact study personnel to schedule testing for anti-cyclic citrullinated peptide-3 (CCP3). The primary outcome measure for each campaign was the click-through rate.

Results

During the web campaign, 413,289 advertisement impressions were displayed, resulting in 428 clicks (click-through rate 0.10%) and only one screened participant. During the English Facebook campaign, 724,815 advertisements were displayed with 6765 clicks (click-through rate 0.93%) and 43 screened participants, significantly greater than the web campaign (P < 0.001). During the Spanish advertisement campaign, 255,730 Spanish advertisements were displayed, resulting in a click-through rate of 2.09% and 24 screened participants, a significantly higher rate than English advertisements. Of participants recruited through social media, 94% were female and 29.8% were Spanish speakers.

Conclusion

Facebook advertisements were superior to web advertisements for participant recruitment. Spanish Facebook advertisements had a greater click-through rate than English Facebook advertisements. Facebook was an effective recruitment method, particularly for Spanish speakers.