臺灣博碩士論文加值系統

關於單一母體仍存活者感染HIV之感染率, Wong el al. (2006)提供一個基於HIV盛行率之橫截數據的估計法. 在該篇文章中, 他們利用此方法分析一筆來自南非 Cape Town 之橫截數據. 原作者把所蒐集的數據分成三個年齡層個別處裡. 因此, 在我們的研究中, 假定不同年齡層有不同的HIV風險函數但彼此之間滿足Cox對比風險模型. 之後, 應用半參數(semiparametric)方法估計所對應的風險參數. 在此, 基線風險函數(baseline hazards function)沒有任何參數假設.

Wong et al. (2006) proposed an estimating procedure to estimate the HIV hazards function of a single population when only HIV prevalence data are available over an extended period of time. The method was illustrated using HIV-prevalence data collected over four years among women in Cape Town, South africa by stratifying the data into three populations based on the age of the women. In this work, we assume women with different age may have different
HIV hazards function but proportional to each other. Then, a semiparametric approach is applied to estimate the risk parameters. No parametric assumptions of the baseline hazards function are required.

1Introduction 1
2Preliminaries 2
2.1 Maximum likelihood estimation . . . . . . . . . . . . . . . . . . . . . .2
2.2 Cox Proportional Hazards Model . . . . . . . . . . . . . . . . . . . . . 3
3 The Statistical Model 4
4 The Trend of The Odds Function 7
5 Simulation Studies 11
6 Example 16
7 Discussion 18
References 20

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