Brookmeyer R, Liao J G
Department of Biostatistics, Johns Hopkins University, Baltimore, Maryland 21205.
Biometrics. 1990 Dec;46(4):1151-63.
The objective of this paper is to develop statistical methods for estimating current and future numbers of individuals in different stages of the natural history of the human immunodeficiency (AIDS) virus infection and to evaluate the impact of therapeutic advances on these numbers. The approach is to extend the method of back-calculation to allow for a multistage model of natural history and to permit the hazard functions of progression from one stage to the next to depend on calendar time. Quasi-likelihood estimates of key quantities for evaluating health care needs can be obtained through iteratively reweighted least squares under weakly parametric models for the infection rate. An approach is proposed for incorporating into the analysis independent estimates of human immunodeficiency virus (HIV) prevalence obtained from epidemiologic surveys. The methods are applied to the AIDS epidemic in the United States. Short-term projections are given of both AIDS incidence and the numbers of HIV-infected AIDS-free individuals with CD4 cell depletion. The impact of therapeutic advances on these numbers is evaluated using a change-point hazard model. A number of important sources of uncertainty must be considered when interpreting the results, including uncertainties in the specified hazard functions of disease progression, in the parametric model for the infection rate, in the AIDS incidence data, in the efficacy of treatment, and in the proportions of HIV-infected individuals receiving treatment.
本文的目的是开发统计方法，以估计人类免疫缺陷（艾滋病）病毒感染自然史不同阶段当前和未来的个体数量，并评估治疗进展对这些数量的影响。方法是扩展反向推算方法，以允许建立自然史的多阶段模型，并使从一个阶段进展到下一个阶段的风险函数取决于日历时间。在感染率的弱参数模型下，通过迭代加权最小二乘法可以获得用于评估医疗需求的关键数量的拟似然估计。提出了一种将从流行病学调查中获得的人类免疫缺陷病毒（HIV）流行率的独立估计纳入分析的方法。这些方法应用于美国的艾滋病疫情。给出了艾滋病发病率以及CD4细胞耗竭的未患艾滋病的HIV感染者数量的短期预测。使用变点风险模型评估治疗进展对这些数量的影响。在解释结果时，必须考虑许多重要的不确定性来源，包括疾病进展的指定风险函数、感染率的参数模型、艾滋病发病率数据、治疗效果以及接受治疗的HIV感染者比例中的不确定性。
