Abstract：
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.
摘要：
对终生健康状况的预防性药物依从性低是全球发病率和死亡率的主要原因。我们在墨西哥实施了一项试点随机对照试验，以测量有条件的经济激励措施在多大程度上帮助男性性工作者提高对HIV预防的暴露前预防（PrEP）的依从性。我们追踪了n=110名男性性工作者超过6个月。在每个季度访问（在第0、3和6个月），所有工人都获得了10美元的交通报销，3个月的免费PrEP供应，并完成了社会行为调查。主要结果是基于每次就诊时收集的头发替诺福韦（TFV）药物浓度水平的药物依从性的客观生物标志物。随机接受干预的个人根据PrEP依从性的分级系统获得激励：那些高（>0.043ng/mgTFV浓度），培养基（0.011至0.042ng/mg），或低(<0.011ng/mg)依从性分别获得$20,$10或$0.使用人口平均伽马广义估计方程模型分析了激励措施对PrEP依从性的六个月综合影响。我们根据性工作者的特征估计了异质治疗效果。激励干预导致头发抗逆转录病毒浓度水平在6个月内增加28.7%，与PrEP依从性增加一致(p=0.05)。对于街头男性性工作者，激励措施对PrEP依从性的影响更大(与互联网）工人（p<0.10）。这些试点结果表明，适度的有条件经济激励措施可能是有效的，在规模上，提高男性性工作者的PrEP依从性，并应在更大的实施试验中进行测试。ClinicalTrials.gov标识符：NCT03674983。
