Comparing Web-Based Venues to Recruit Gay, Bisexual, and Other Cisgender Men Who Have Sex With Men to a Large HIV Prevention Service in Brazil: Evaluation Study
Authors: Bezerra Daniel Rodrigues Barros , Jalil Cristina Moreira , Jalil Emilia Moreira , Coelho Lara Esteves , Netto Eduardo Carvalheira , Freitas Josias , Monteiro Laylla , Santos Toni , Souza Cleo , Hoagland Brenda , Veloso Valdilea Gonçalves , Grinsztejn Beatriz , Cardoso Sandra Wagner , Torres Thiago Silva 
Published: August 2022

Background
Internet and mobile phones, widely available in Brazil, could be used to disseminate information about HIV prevention and to recruit gay, bisexual, and other cisgender men who have sex with men (MSM) to HIV prevention services. Data evaluating the characteristics of MSM recruited through different web-based strategies and estimating their cost and yield in the country are not available.

Objective
We aimed to describe a web-based recruitment cascade, compare the characteristics of MSM recruited to a large HIV prevention service in Rio de Janeiro according to web-based venues, and estimate the cost per participant for each strategy.

Methods
We promoted advertisements on geosocial networking (GSN) apps (Hornet and Grindr) and social media (Facebook and Instagram) from March 2018 to October 2019. The advertisements invited viewers to contact a peer educator to schedule a visit at the HIV prevention service. Performance of web-based recruitment cascade was based on how many MSM (1) were reached by the advertisement, (2) contacted the peer educator, and (3) attended the service. We used chi-square tests to compare MSM recruited through GSN apps and social media. The estimated advertisement cost to recruit a participant was calculated by dividing total advertisement costs by number of participants who attended the service or initiated preexposure prophylaxis (PrEP).

Results
Advertisement reached 1,477,344 individuals; 1270 MSM contacted the peer educator (86 contacts per 100,000 views)—564 (44.4%), 401 (31.6%) and 305 (24.0%)—through social media, Grindr, and Hornet. Among the 1270 individuals who contacted the peer educator, 36.3% (n=461) attended the service with similar proportion for each web-based strategy (social media: 203/564, 36.0%; Grindr: 152/401, 37.9%; and Hornet: 107/305, 35.1%). MSM recruited through GSN apps were older (mean age 30 years vs 26 years; P<.001), more frequently self-reported as White (111/247, 44.9% vs 62/191, 32.5%; P=.03), and had higher schooling level (postsecondary: 157/254, 61.8% vs 94/194, 48.5%; P=.007) than MSM recruited through social media. GSN apps recruited MSM with higher HIV risk as measured by PrEP eligibility (207/239, 86.6% vs 133/185, 71.9%; P<.001) compared with social media, but there was no difference in PrEP uptake between the two strategies (P=.22). The estimated advertisement costs per participant attending the HIV prevention service were US $28.36 for GSN apps and US $12.17 for social media. The estimated advertisement costs per participant engaging on PrEP were US $58.77 for GSN apps and US $27.75 for social media.

Conclusions
Social media and GSN app advertisements were useful to disseminate information on HIV prevention strategies and to recruit MSM to a large HIV prevention service in Brazil. Compared to GSN apps, social media advertisements were less expensive and reached more vulnerable and younger MSM. Digital marketing campaigns should use different and complementary web-based venues to reach a plurality of MSM.