Goggins W B, Finkelstein D M, Zaslavsky A M
Massachusetts General Hospital, 50 Staniford St, Boston, MA 02114, USA.
Stat Med. 1999 Oct 30;18(20):2737-47. doi: 10.1002/(sici)1097-0258(19991030)18:20<2737::aid-sim199>3.0.co;2-7.
The latency time of an infectious disease is defined as the time from infection to disease onset. This paper applies the proportional hazards model to estimate the effect of covariates on latency when the time of disease onset is exact or right-censored but the time of infection is interval-censored. We use a Monte Carlo EM algorithm to estimate parameters of the joint distribution of infection times and latency times. At each EM iteration, exact infection times are multiply imputed from the density determined by the parameters of the infection and latency time distributions. The methodology is tested using a simulation study and is applied to data from a cohort of haemophiliacs with HIV disease.
传染病的潜伏期定义为从感染到发病的时间。本文应用比例风险模型来估计协变量对潜伏期的影响，此时发病时间是精确的或右删失的，但感染时间是区间删失的。我们使用蒙特卡罗期望最大化（EM）算法来估计感染时间和潜伏期联合分布的参数。在每次EM迭代中，从由感染时间和潜伏期分布参数确定的密度中多次插补精确的感染时间。该方法通过模拟研究进行了测试，并应用于一组感染HIV的血友病患者的数据。
