Recruiting sexual minority youth for a drug abuse prevention trial: Comparing Instagram and Facebook.

Background: Despite youth's shift from Facebook to Instagram, the literature on how to use Instagram to recruit youth for clinical trials is scant. This paper reports procedures and comparative metrics on the use of Facebook and Instagram to recruit a nationwide sample (N = 1216) of LGBQ youth, aged 15 and 16 years, for an online drug abuse prevention trial.

Methods: Our recruitment campaign used ads on Facebook and promoted posts on Instagram. Ads and posts shared common images, headlines, and captions. Ads and posts directed youth to a study recruitment website for informed consent and enrollment procedures.

Results: Our campaign ran for 48 non-consecutive days, yielded N = 1216 participants, had a total cost of $25,400.31, and an average cost per participant of $20.89. Facebook ads and Instagram promoted posts ran for a similar number of days. However, compared to Instagram, Facebook ads cost more than twice as much (115 %), had 51 % fewer clicks, and had an average cost-per-click that was 338 % higher. Furthermore, despite being shown to users more than 4 times as often and garnering more than twice as many unique views, Facebook ads had a click-through-rate that was 90 % lower than Instagram promoted posts.

Conclusion: Instagram promoted posts outperformed ads on Facebook by driving more potential participants to the study recruitment website and for less money.