Article Text
Abstract
Background Optimizing HIV pre-exposure prophylaxis (PrEP) roll-out requires insight in dosing regimen preferences, frequency and determinants of regimen switches, and PrEP discontinuation. We assessed user-initiated switches and factors associated with switching or stopping daily (dPrEP) or event-driven (edPrEP) PrEP regimens among men who have sex with men (MSM) participating in a PrEP demonstration project in Amsterdam.
Methods At enrolment, participants could choose either dPrEP or edPrEP. Participants were able to switch regimens at each quarterly study visit. We evaluated transition intensities (TI) and (time-varying) factors associated with switching (i) between edPrEP and dPrEP and (ii) from either PrEP regimen to discontinuing PrEP, using a continuous-time, multi-state Markov model.
Results Of 367 enrolled participants with follow-up, 73.3% chose dPrEP and 26.7% edPrEP at enrolment. During a median follow-up of 2.6 years (IQR=2.4–2.7), 114 (cumulative proportion=36.5%) switched their PrEP regimen at least once. In total, 85 switches from edPrEP to dPrEP (TI=0.41, 95%CI=0.33–0.50) and 98 from dPrEP to edPrEP (TI=0.17, 95%CI=0.14–0.20) occurred, with transitions from edPrEP to dPrEP 2.43-times more likely (95%CI=1.84–3.22) than vice versa. In multivariable analysis, switching from edPrEP to dPrEP was associated with lower age, higher number of sex acts with casual partners, chemsex and living alone, whereas switching from dPrEP to edPrEP was associated with lower age, lower number of casual partners, higher number of sex acts with casual partners and lower score on the New Sexual Satisfaction Scale. A total of 61 individuals discontinued PrEP, with no difference from which regimen: edPrEP (n=22, TI=0.10, 95%CI=0.06–0.15) and dPrEP (n=39, TI=0.06, 95%CI=0.04–0.08). PrEP discontinuation was only associated with lower age (from dPrEP).
Conclusion Switching between PrEP regimens is common and more frequent among younger MSM and MSM with higher number of sex acts, who may benefit from client-centered counseling. Rates of PrEP discontinuation are low and are linked to younger age.
Disclosure No significant relationships.