Study on Pre-Exposure Prophylaxis Regimens among Men Who Have Sex with Men: A Prospective Cohort Study

Abstract

Background: There are limited studies on the medication regimen of pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM) in China. This study compared the effectiveness of and adherence to two prophylactic HIV medication regimens, which provided evidence and guidance for the application and promotion of the PrEP strategy in the MSM population in China. Methods: We conducted an open, non-randomized, multicenter, parallel, controlled clinical intervention study in western China. Subjects were recruited by convenience sampling at research centers in Chongqing, Guangxi, Xinjiang and Sichuan, China from April 2013 to March 2015, and they were categorized into the daily PrEP, event-driven and blank control groups. Tenofovir disoproxil fumarate (TDF; 300 mg/dose) was administered to subjects in the daily PrEP and event-driven groups, and all subjects were followed up every 12 weeks for 96 weeks. Demographic, behavioral, psychological characteristics and AIDS-related attitudes were assessed using self-completed questionnaires. TDF serum concentrations in subjects in Chongqing and Sichuan were quantified after systematic sampling. Results: Of the 2422 enrolled MSM, 856 were eligible for statistical analysis (PrEP group: 385 and event-driven group: 471); 30 and 32 subjects in daily PrEP and event-driven groups, respectively, were HIV-positive; the incidence of HIV infection was as follows: daily PrEP group, 6.60 cases/100 person-years and event-driven group, 5.57 cases/100 person-years (relative risk (RR) 95% confidence interval (CI) was 0.844 (0.492–1.449)); HIV incidence did not differ significantly when stratified by medication adherence or sites. When the medication adherence rate was ≥80%, the median TDF serum concentrations were 0.458 mg/L, and 0.429 mg/L in the daily PrEP, and event-driven groups, respectively (not significant; p > 0.05); Subjects who were in the event-driven PrEP group (OR = 2.152, 95% CI: 1.566–2.957), had fewer male sexual partners in the last two weeks (OR = 0.685, 95% CI: 0.563–0.834), were one year older on average (OR = 1.022, 95% CI: 1.002–1.043), considered that medication kept them safe, were less worried about others knowing they took medicine and were more likely to have high adherence. Conclusions: The efficacies of daily TDF and event-driven TDF use were not significantly different in preventing new infections among HIV-negative MSM. Event-driven TDF use is economical and effective and is worth popularizing. Our results provide evidence for the application and promotion of the PrEP strategy in the MSM population in China.

PrEP risk perception and adherence among men who have sex with men: a prospective cohort study based on growth mixture model

“…Our findings suggest that the MSM population in the event-driven group had higher adherence, which is consistent with Wu’s results [ 23 ]. In addition, MSM who had high-risk anal sex had lower adherence compared to MSM who did not.…”

“…If an illogical response occurs, participants will be reminded to answer the question again at the study site. Adherence ≥ 80% defined as "high-level" [ 20 , 22 , 23 ]. High-risk anal sex was defined as not using a condom during anal sex.…”

Comparison between daily and on‐demand PrEP (pre‐exposure prophylaxis) regimen in covering condomless anal intercourse for men who have sex with men in Hong Kong: A randomized, controlled, open‐label, crossover trial

“…Previous studies showed that age and risk profile were associated with one's choice of PrEP regimen [7], which subsequently affected the sexually transmitted infection (STI) incidence during PrEP use [8]. In open-label trials, breakthrough HIV infection was similarly uncommon for both daily and on-demand PrEP [7][8][9][10].…”

“…Previous studies showed that age and risk profile were associated with one's choice of PrEP regimen [7], which subsequently affected the sexually transmitted infection (STI) incidence during PrEP use [8]. In open‐label trials, breakthrough HIV infection was similarly uncommon for both daily and on‐demand PrEP [7–10]. In Hong Kong, there have not been any government‐funded PrEP programmes and only patented TDF/FTC was available through prescriptions, the cost of which was well beyond the local MSM's affordability [11].…”

Factors Influencing the Intention of MSM to Use the PrEP Intelligent Reminder System

“…Among MSM who are not infected by HIV, the efficacy and safety of long-term use of PrEP to prevent new HIV infection has been confirmed. [10][11][12] The US Centers for Disease Control and Prevention found that the use of PrEP can reduce the rate of HIV infection in high-risk individuals by more than 90%. 13 In 2015, the WHO officially included PrEP in its guidelines for preventing HIV infection in people who engage in high-risk sexual behaviors, indicating that PrEP is now a recognized means of preventing HIV infection.…”