Dureau J, Kalogeropoulos K, Vickerman P, Pickles M, Boily M-C
London School of Economics and Political Science UK.
London School of Hygiene and Tropical Medicine UK.
J R Stat Soc Ser C Appl Stat. 2016 Feb;65(2):237-257. doi: 10.1111/rssc.12116. Epub 2015 Aug 10.
Evaluation of large-scale intervention programmes against human immunodeficiency virus (HIV) is becoming increasingly important, but impact estimates frequently hinge on knowledge of changes in behaviour such as the frequency of condom use over time, or other self-reported behaviour changes, for which we generally have limited or potentially biased data. We employ a Bayesian inference methodology that incorporates an HIV transmission dynamics model to estimate condom use time trends from HIV prevalence data. Estimation is implemented via particle Markov chain Monte Carlo methods, applied for the first time in this context. The preliminary choice of the formulation for the time varying parameter reflecting the proportion of condom use is critical in the context studied, because of the very limited amount of condom use and HIV data available. We consider various novel formulations to explore the trajectory of condom use over time, based on diffusion-driven trajectories and smooth sigmoid curves. Numerical simulations indicate that informative results can be obtained regarding the amplitude of the increase in condom use during an intervention, with good levels of sensitivity and specificity performance in effectively detecting changes. The application of this method to a real life problem demonstrates how it can help in evaluating HIV interventions based on a small number of prevalence estimates, and it opens the way to similar applications in different contexts.
评估针对人类免疫缺陷病毒（HIV）的大规模干预项目正变得越来越重要，但影响评估常常依赖于对行为变化的了解，比如随着时间推移避孕套使用频率等，或者其他自我报告的行为变化，而对于这些我们通常只有有限的或可能有偏差的数据。我们采用一种贝叶斯推理方法，该方法纳入了一个HIV传播动力学模型，以从HIV流行数据中估计避孕套使用的时间趋势。估计是通过粒子马尔可夫链蒙特卡罗方法实现的，这是首次在此背景下应用。在研究的背景下，反映避孕套使用比例的时变参数公式的初步选择至关重要，因为可用的避孕套使用和HIV数据量非常有限。我们基于扩散驱动轨迹和平滑S形曲线，考虑各种新颖的公式来探索避孕套使用随时间的轨迹。数值模拟表明，关于干预期间避孕套使用增加的幅度可以获得有价值的结果，在有效检测变化方面具有良好的敏感性和特异性表现。将该方法应用于实际问题表明了它如何能够基于少量流行率估计来帮助评估HIV干预措施，并且为在不同背景下的类似应用开辟了道路。
