Incentivizing adherence to pre-exposure prophylaxis for HIV prevention a randomized pilot trial among male sex workers in Mexico

TY - JOUR

T1 - Incentivizing adherence to pre-exposure prophylaxis for HIV prevention a randomized pilot trial among male sex workers in Mexico

AU - Galárraga, Omar

AU - Wilson-Barthes, Marta

AU - Chivardi, Carlos

AU - Gras-Allain, Nathalie

AU - Alarid-Escudero, Fernando

AU - Gandhi, Monica

AU - Mayer, Kenneth H

AU - Operario, Don

N1 - © 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

PY - 2025/3/1

Y1 - 2025/3/1

N2 - Low adherence to preventative medications against life-long health conditions is a major contributor to global morbidity and mortality. We implemented a pilot randomized controlled trial in Mexico to measure the extent to which conditional economic incentives help male sex workers increase their adherence to pre-exposure prophylaxis (PrEP) for HIV prevention. We followed n = 110 male sex workers over 6 months. At each quarterly visit (at months 0, 3, and 6), all workers received a $10 transport reimbursement, a free 3-month PrEP supply, and completed socio-behavioral surveys. The primary outcome was an objective biomarker of medication adherence based on tenofovir (TFV) drug concentration levels in hair collected at each visit. Individuals randomized to the intervention received incentives based on a grading system as a function of PrEP adherence: those with high (> 0.043 ng/mg TFV concentration), medium (0.011 to 0.042 ng/mg), or low (< 0.011 ng/mg) adherence received $20, $10, or $0, respectively. Six-month pooled effects of incentives on PrEP adherence were analyzed using population-averaged gamma generalized estimating equation models. We estimated heterogeneous treatment effects by sex worker characteristics. The incentive intervention led to a 28.7% increase in hair antiretroviral concentration levels over 6 months consistent with increased PrEP adherence (p = 0.05). The effect of incentives on PrEP adherence was greater for male sex workers who were street-based (vs. internet) workers (p < 0.10). These pilot findings suggest that modest conditional economic incentives could be effective, at scale, for improving PrEP adherence among male sex workers, and should be tested in larger implementation trials. ClinicalTrials.gov Identifier: NCT03674983.

AB - Low adherence to preventative medications against life-long health conditions is a major contributor to global morbidity and mortality. We implemented a pilot randomized controlled trial in Mexico to measure the extent to which conditional economic incentives help male sex workers increase their adherence to pre-exposure prophylaxis (PrEP) for HIV prevention. We followed n = 110 male sex workers over 6 months. At each quarterly visit (at months 0, 3, and 6), all workers received a $10 transport reimbursement, a free 3-month PrEP supply, and completed socio-behavioral surveys. The primary outcome was an objective biomarker of medication adherence based on tenofovir (TFV) drug concentration levels in hair collected at each visit. Individuals randomized to the intervention received incentives based on a grading system as a function of PrEP adherence: those with high (> 0.043 ng/mg TFV concentration), medium (0.011 to 0.042 ng/mg), or low (< 0.011 ng/mg) adherence received $20, $10, or $0, respectively. Six-month pooled effects of incentives on PrEP adherence were analyzed using population-averaged gamma generalized estimating equation models. We estimated heterogeneous treatment effects by sex worker characteristics. The incentive intervention led to a 28.7% increase in hair antiretroviral concentration levels over 6 months consistent with increased PrEP adherence (p = 0.05). The effect of incentives on PrEP adherence was greater for male sex workers who were street-based (vs. internet) workers (p < 0.10). These pilot findings suggest that modest conditional economic incentives could be effective, at scale, for improving PrEP adherence among male sex workers, and should be tested in larger implementation trials. ClinicalTrials.gov Identifier: NCT03674983.

KW - Humans

KW - Male

KW - HIV Infections/prevention & control

KW - Sex Workers/statistics & numerical data

KW - Mexico

KW - Pre-Exposure Prophylaxis/economics

KW - Pilot Projects

KW - Adult

KW - Medication Adherence

KW - Anti-HIV Agents/therapeutic use

KW - Motivation

KW - Tenofovir/therapeutic use

KW - Young Adult

KW - Hair/chemistry

U2 - 10.1007/s10198-024-01705-y

DO - 10.1007/s10198-024-01705-y

M3 - Article

C2 - 39002005

SN - 1618-7598

VL - 26

SP - 299

EP - 311

JO - The European journal of health economics : HEPAC : health economics in prevention and care

JF - The European journal of health economics : HEPAC : health economics in prevention and care

IS - 2

ER -