The use of online social media for the recruitment of people living with HIV in Spain and Latin America: Lessons from two studies.

Various barriers make recruiting a difficult task for researchers, especially when recruiting people living with HIV (PLWH) or conducting longitudinal studies. Effective recruitment is crucial to the validity of studies, and in this regard, social media can come to aid, although researchers usually rely on paid advertisements. This paper describes the free social media strategies used for participant recruitment in two studies carried out with PLWH in Spain and Latin America. Study 1 was a cross-sectional study on the validation of two stigma scales with a 1-month retest. Study 2 was a longitudinal study exploring the mental health of newly diagnosed PLWH, with a second assessment after 6 months. Facebook posts, Twitter mentions, and discussion forums were used in both studies. Study 2 also recruited participants through a healthcare centre. In Study 1, 5-month recruitment yielded a sample of 458 PLWH, averaging 91.6 surveys/month and a 43% retention rate. In study 2, recruitment took 16 months, yielding a final sample of 145 newly diagnosed PLWH, 92 from the healthcare centre (5.75 surveys/month) and 53 from social media (3.31 surveys/month), with 95% and 60% retention rates, respectively. Participants in Study 2 did not differ in sociodemographic characteristics by recruitment method, except for the region of origin and financial difficulty (more diverse origin and greater difficulty emerged in social media participants). Greater psychological distress and lower personal and social resources were also found in social media participants. These data indicate that free social media recruitment is a feasible and effective tool for the recruitment of Spanish-speaking PLWH, although it is best used in combination with traditional methods for newly diagnosed PLWH and longitudinal studies.