Sakarovitch Charlotte, Alioum Ahmadou, Ekouevi Didier K, Msellati Philippe, Leroy Valériane, Dabis François
INSERM E 03 38, Bordeaux F 33076, France.
Stat Med. 2007 Jan 30;26(2):320-35. doi: 10.1002/sim.2540.
Ades and Medley provided the first flexible method for estimating age- and time-specific HIV incidence using HIV prevalence data collected among pregnant women and adjusting for the effect of differential selection between infected and uninfected women. This paper extends the approach proposed by these authors. We used a parametric model that allows the relative inclusion rate to depend on both age, calendar time, and duration of HIV infection. We developed a two dimensional penalized log-likelihood approach for estimating time- and age-specific incidence using a binomial likelihood function and a quadratic roughness penalty which allows smoothing over both age and time. Identifiability of the model parameters and effect of sample size are studied through simulations. The method is illustrated using prenatal HIV testing data recorded from 1995 to 2002 in Abidjan, Côte d'Ivoire, to estimate the HIV annual incidence rate among women aged 12-40 year old, from the beginning of the epidemic to 2002. We show that estimated incidence rates are highly dependent on hypotheses made to model the relative inclusion rate. Despite this dependency, the application of the method leads to new and accurate findings on HIV incidence qualitative features in Abidjan. We highlight the relevance of such a method in monitoring the dynamics of HIV epidemic in Africa which is essential for planning vaccine trials and future treatment needs, and for assessment of prevention policy.
阿德斯和梅德利提出了第一种灵活的方法，利用在孕妇中收集的艾滋病毒流行率数据，并针对感染妇女和未感染妇女之间的差异选择效应进行调整，来估计特定年龄和特定时间的艾滋病毒发病率。本文扩展了这些作者提出的方法。我们使用了一个参数模型，该模型允许相对纳入率取决于年龄、日历时间以及艾滋病毒感染持续时间。我们开发了一种二维惩罚对数似然方法，用于使用二项式似然函数和二次粗糙度惩罚来估计特定时间和特定年龄的发病率，这允许在年龄和时间上进行平滑处理。通过模拟研究了模型参数的可识别性和样本量的影响。使用1995年至2002年在科特迪瓦阿比让记录的产前艾滋病毒检测数据来说明该方法，以估计从疫情开始到2002年12至40岁女性中的艾滋病毒年发病率。我们表明，估计的发病率高度依赖于为模拟相对纳入率所做的假设。尽管存在这种依赖性，但该方法的应用在阿比让艾滋病毒发病率的定性特征方面得出了新的准确发现。我们强调了这种方法在监测非洲艾滋病毒流行动态方面的相关性，这对于规划疫苗试验和未来治疗需求以及评估预防政策至关重要。
