Becker Niels G, Lewis James J C, Li Zhengfeng, McDonald Ann
National Centre for Epidemiology and Population Health, The Australian National University, Canberra ACT 0200, Australia.
Stat Med. 2003 Jul 15;22(13):2177-90. doi: 10.1002/sim.1406.
A method for reconstructing the HIV infection curve from data on both HIV and AIDS diagnoses is enhanced by using age as a covariate and by using the diagnosis data to estimate parameters that were previously assumed known. Maximum likelihood estimation is used for parameters of the induction distribution. Each of the set of parameters that specify the baseline rate of infection over time and the set of parameters giving the relative susceptibility over age are estimated by maximizing the likelihood subject to a smoothness requirement. We find that estimating the extra parameters is feasible, producing estimates with good precision. Including age as a covariate gives 90 per cent confidence intervals for the HIV incidence curve that are about 20 per cent narrower than those obtained when age data are not used.
一种从艾滋病病毒（HIV）和艾滋病诊断数据重建HIV感染曲线的方法得到了改进，具体方式是将年龄用作协变量，并利用诊断数据来估计先前假定为已知的参数。对诱导分布的参数采用最大似然估计。通过在满足平滑性要求的条件下最大化似然性，来估计指定随时间变化的基线感染率的参数集以及给出年龄相对易感性的参数集。我们发现，估计额外的参数是可行的，所产生的估计具有良好的精度。将年龄作为协变量时，HIV发病率曲线的90%置信区间比不使用年龄数据时获得的置信区间窄约20%。
