Wilton James, Kain Taylor, Fowler Shawn, Hart Trevor A, Grennan Troy, Maxwell John, Tan Darrell Hs
CATIE (Canadian AIDS Treatment Information Exchange), Toronto, Canada.
Department of Medicine, University of Toronto, Toronto, Canada.
J Int AIDS Soc. 2016 Jun 3;19(1):20777. doi: 10.7448/IAS.19.1.20777. eCollection 2016.
Identifying appropriate pre-exposure prophylaxis (PrEP) candidates is a challenge in planning for the safe and effective roll-out of this strategy. We explored the use of a validated HIV risk screening tool, HIV Incidence Risk Index for Men who have Sex with Men (HIRI-MSM), to identify "optimal" candidates among MSM testing at a busy sexual health clinic's community testing sites in Toronto, Canada.
Between November 2014 and April 2015, we surveyed MSM undergoing anonymous HIV testing at community testing sites in Toronto, Canada, to quantify "optimal" candidates for scaling up PrEP roll-out, defined as being at high objective HIV risk (scoring ≥10 on the HIRI-MSM), perceiving oneself at moderate-to-high HIV risk and being willing to use PrEP. Cascades were constructed to identify barriers to broader PrEP uptake. The association between HIRI-MSM score and both willingness to use PrEP and perceived HIV risk were explored in separate multivariable logistic regression analyses.
Of 420 respondents, 64.4% were objectively at high risk, 52.5% were willing to use PrEP and 27.2% perceived themselves at moderate-to-high HIV risk. Only 16.4% were "optimal" candidates. Higher HIRI-MSM scores were positively associated with both willingness to use PrEP (aOR=1.7 per 10 score increase, 95%CI=1.3-2.2) and moderate-to-high perceived HIV risk (aOR=1.7 per 10 score increase, 95%CI=1.2-2.3). The proportion of men who were "optimal" candidates increased to 42.9% when the objective HIV risk cut-off was changed to top quartile of HIRI-MSM scores (≥26). In our full cascade, a very low proportion (5.3%) of MSM surveyed could potentially benefit from PrEP under current conditions. The greatest barrier in the cascade was low perception of HIV risk among high-risk men, but considerable numbers were also lost in downstream cascade steps. Of men at high objective HIV risk, 68.3% did not perceive themselves to be at moderate-to-high HIV risk, 23.6% were unaware of PrEP, 40.1% were not willing to use PrEP, 47.6% lacked a family physician with whom they felt comfortable discussing sexual health, and 31.6% had no means to cover the cost of PrEP.
A higher HIRI-MSM cut-off may be helpful for identifying candidates for PrEP scale-up. Improving engagement in the PrEP cascade will require interventions to simultaneously address multiple barriers.
在规划安全有效的暴露前预防（PrEP）策略推广时，确定合适的PrEP候选者是一项挑战。我们探索使用一种经过验证的HIV风险筛查工具，即男男性行为者HIV感染风险指数（HIRI-MSM），在加拿大多伦多一家繁忙的性健康诊所的社区检测点，识别接受检测的男男性行为者中的“最佳”候选者。
2014年11月至2015年4月期间，我们对在加拿大多伦多社区检测点接受匿名HIV检测的男男性行为者进行了调查，以量化扩大PrEP推广的“最佳”候选者，定义为具有高客观HIV风险（HIRI-MSM评分≥10）、自认为具有中度至高度HIV风险且愿意使用PrEP。构建级联模型以识别更广泛采用PrEP的障碍。在单独的多变量逻辑回归分析中，探讨了HIRI-MSM评分与使用PrEP的意愿以及感知到的HIV风险之间的关联。
在420名受访者中，64.4%客观上处于高风险，52.5%愿意使用PrEP，27.2%自认为具有中度至高度HIV风险。只有16.4%是“最佳”候选者。HIRI-MSM评分越高，与使用PrEP的意愿（每增加10分调整后的比值比[aOR]=1.7，95%置信区间[CI]=1.3 - 2.2）和中度至高度感知到的HIV风险（每增加10分aOR=1.7，95%CI=1.2 - 2.3）均呈正相关。当将客观HIV风险临界值改为HIRI-MSM评分的上四分位数（≥26）时，“最佳”候选者的比例增加到42.9%。在我们的完整级联模型中，在当前条件下，接受调查的男男性行为者中只有非常低的比例（5.3%）可能从PrEP中受益。级联模型中最大的障碍是高风险男性对HIV风险的低感知，但在下游级联步骤中也有相当数量的人流失。在客观HIV风险高的男性中，68.3%不认为自己具有中度至高度HIV风险，23.6%不知道PrEP，40.1%不愿意使用PrEP，47.6%没有感到可以舒适地讨论性健康问题的家庭医生，31.6%没有支付PrEP费用的能力。
较高的HIRI-MSM临界值可能有助于识别扩大PrEP规模的候选者。改善PrEP级联模型中的参与度将需要同时解决多个障碍的干预措施。
