成比例危險迴歸模式常被用於分析存活資料，Weibull模式更是其中惟一兼具加速失敗特性者。本論文將利用兩種分析方法，以研究任意設限及截斷資料的Weibull迴歸模式。第一種方法是利用最大概似估計法求算設限及截斷資料下的參數估計值（MLE），第二種方法則是對左設限及區間設限分別以所在區間之中點代入，稱其為中點估計法，再求算模式中的參數估計值（MDE）。並對此兩種估計方法進行比較。模擬結果顯示，相當地大樣本之下，最大概似估計法在許多情況均優於中點估計法；而在樣本少、危險率為平穩或接近平穩且區間設限比率約為0.5時，中點估計法是可被推薦的。而且，本論文亦提出對設限及截斷資料的Weibull模式之適合度檢驗程序。

The proportional hazards regression model is most commonly used model for lifetime data. The Weibull model is the only parametric model which has both a proportional hazards representation and an accelerated failure-time representation. This paper studies the use of a Weibull-based proportional hazards regression model when any censored and truncated data are observed. Two alternative methods of analysis are considered. First, the maximum likelihood estimates（MLEs） of parameters are computed for the observed censoring and truncation pattern. Second, the estimates where midpoints are substituted for left- and interval-censored data（midpoint estimation, MDE）are computed. Then, MLEs are compared with MDEs. Simulation studies indicate that for relative large samples there are many instances when the MLE is superior to the MDE. For small samples where the hazard rate is flat or nearly so, and the percentage of interval-censored data is nearly half of samples, the MDE is adequate. Also, an evaluation of the adequacy of the Weibull model for any censored and truncated data is proposed.

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