Intention to Use Pre-Exposure Prophylaxis Among Age Groups of Brazilian Men Who Have Sex With Men: National Cross-Sectional Study.

Background: In Brazil, men who have sex with men (MSM) are disproportionately affected by the HIV epidemic, mirroring global trends. Despite advancements in HIV prevention, such as pre-exposure prophylaxis (PrEP), uptake remains uneven among different MSM age groups, influenced by various sexual behaviors, risk perceptions, and social stigmas.

Objective: This study aimed to investigate factors associated with PrEP intentions among Brazilian MSM across different age groups.

Methods: A cross-sectional electronic survey was conducted with Brazilian MSM aged 18 years and above.

Results: PrEP intentions were expressed by 55.1% (2390/4341) of participants. Among those under 25 years old, frequent barebacking was associated with a 25.4-fold higher prevalence of PrEP intentions (95% CI 18.18-35.48). Conversely, having one or more casual sexual partners in the last 30 days (2164/3838) was associated with a 22% lower frequency of PrEP intentions (95% CI 0.72-0.85). The practice of chemsex was also associated with a lower prevalence of PrEP intentions (adjusted prevalence ratio [aPR] 0.96; 95% CI 0.94-0.98). Among individuals aged 25-49 years, the practice of double penetration was associated with a higher prevalence of PrEP intentions (aPR 1.22; 95% CI .13-1.32), as was being a receptive or versatile partner (aPR 1.27; 95% CI 1.04-1.55 and aPR 1.23; 95% CI 1.01-1.49). In addition, within this age range, a higher prevalence of PrEP intentions (over 10% [258/429]) was found among those with specific characteristics, such as a previous diagnosis of syphilis (aPR 1.12; 95% CI 1.03-1.22). However, being single (aPR 0.90; 95% CI 0.83-0.97) and having a partner who used PrEP (aPR 0.82; 95% CI 0.72-0.93) were associated with a lower prevalence of PrEP intentions. For MSM aged ≥50 years, a higher prevalence of PrEP intentions was associated with the practice of double penetration (aPR 1.31; 95% CI 1.20-1.43), as well as being a receptive (aPR 1.27; 95% CI 1.04-1.55) or versatile partner (aPR 1.23; 95% CI 1.01-1.50). The practice of group sex was independently associated with a lower prevalence of PrEP intentions exclusively among MSM aged ≥50 years (aPR 0.82; 95% CI 0.75-0.89).

Conclusions: The study highlights significant generational differences in factors influencing PrEP intentions among Brazilian MSM. It underscores the need for tailored HIV prevention strategies that consider the unique behaviors and perceptions of different age groups. By addressing these nuances, public health initiatives can more effectively promote PrEP use, catering to the diverse needs of the MSM community and contributing to the reduction of HIV infection rates.