Westreich Daniel, Edwards Jessie K
Am J Epidemiol. 2015 Nov 15;182(10):857-60. doi: 10.1093/aje/kwv200. Epub 2015 Oct 19.
Preexposure prophylaxis (PrEP) is a promising approach to prevention of human immunodeficiency virus (HIV) transmission, in which an HIV-negative individual takes a single daily dose of an antiretroviral drug so that, if exposed to HIV, an active antiretroviral drug is already present in his or her system. In this issue of the Journal, Murnane et al. (Am J Epidemiol. 2015;182(10):848-856) use data from the Partners PrEP Study (Kenya and Uganda, 2008-2011) to estimate the efficacy of PrEP under perfect adherence. We discuss Murnane et al.'s work and then examine the larger issues of generalizability or transportability of findings from a randomized trial to a new setting when adherence to an intervention determines its effectiveness. We discuss sufficient conditions for generalizability and use causal directed acyclic graphs to show how these assumptions might play out when trials are used to make inferences about the effect of PrEP in current and future real-world target populations.
暴露前预防（PrEP）是一种很有前景的预防人类免疫缺陷病毒（HIV）传播的方法，即HIV阴性个体每日服用一剂抗逆转录病毒药物，这样如果接触到HIV，其体内已存在活性抗逆转录病毒药物。在本期《杂志》中，莫纳内等人（《美国流行病学杂志》。2015年；182(10):848 - 856）利用来自伴侣PrEP研究（肯尼亚和乌干达，2008 - 2011年）的数据来估计完全依从情况下PrEP的疗效。我们讨论了莫纳内等人的工作，然后探讨了一个更大的问题，即当对一种干预措施的依从性决定其有效性时，如何将随机试验的结果推广或迁移到新的环境中。我们讨论了可推广性的充分条件，并使用因果有向无环图来展示当利用试验推断PrEP在当前和未来现实世界目标人群中的效果时，这些假设可能如何发挥作用。
