Abstract Body

The effectiveness of pre-exposure prophylaxis (PrEP) depends on optimizing adherence; however, few (if any) brief counseling interventions have demonstrated efficacy improving PrEP adherence in real-world settings. This analysis presents data from SPARK, a PrEP demonstration/implementation project conducted at a community-based health center in New York City.

Participants were 301 men who have sex with men and transgender women (ages 18-63; 49% white) who were patients at the health center and chose to start PrEP. SPARK tested the efficacy of two brief interventions: a sexual health intervention (SHI) designed to frame PrEP use as part of sexual health, and a PrEP adherence intervention (AI) designed to provide detailed information about the rationale for daily dosing and concrete logistical adherence support. Each intervention was tested against an educational control, based on existing clinic protocols (i.e., treatment as usual (TAU)). Participants were randomly assigned to one of four conditions, in which they received SHI only, AI only, both, or neither. Adherence was monitored using dried blood spot testing at 3- and 6-month follow-up visits.

Overall adherence in the study was high; almost 93% of participants demonstrated drug levels consistent with >= 4/week dosing (TDF ≥ 700 fmol) at 3M and 90.3% demonstrated these levels at 6M. At 3M, participants who had received one or both of the brief interventions demonstrated significantly higher adherence, compared to those who received neither. Specifically, 96.6% of participants who received at least one brief intervention demonstrated adherence ≥700fmol, compared to only 84% among those who received TAU (p = .002). TAU participants also reported more missed pills, compared to the intervention groups (p = .04). Adherence at 3M did not differ by demographic factors (age, race, income, education, insurance). At 6M there was a trend toward greater adherence in the intervention conditions (92.1% vs. 85.7%), but this difference was not statistically significant. Participants with <700fmol at 6M were more likely to be Black; there were no other demographic factors associated with lower adherence.

A brief client-centered counseling intervention can significantly improve PrEP adherence in a real world setting, even among patients who are highly motivated to adhere. Additional ‘boosters’ may be needed at follow-up visits to better support highest priority patients.