https://scholars.lib.ntu.edu.tw/handle/123456789/112397
標題: | 具誘導訊息設限之二元有序間隔時間的排序相關係數估計 Estimation of rank correlation coefficient for two serial gap times in the presence of induced informative censoring |
作者: | 傅宗襁 Fu, Tsung-Chiang |
關鍵字: | 間隔時間;誘導訊息設限;倒數權重;有序事件;U統計量;Gap times;Induced informative censoring;Inverse weighted;Serial events;U statistics;Kendall''s tau | 公開日期: | 2009 | 摘要: | 在追蹤研究中,針對個體自起始事件後,可能發生的兩事件進行觀察而據此收集形成的資料型態稱為二元事件資料。分析二元事件資料時,過去文獻多考慮以下兩種時間尺度:事件發生時間及兩相鄰事件的間距時間。當兩事件有固定的時間順序時,則多以兩相鄰事件的間距時間,即間隔時間,為時間尺度進行分析。過去文獻中尚未有研究者針對二元有序間隔時間的相關性測度進行探討。一般來說,由於誘導訊息設限的問題,並不適合用分析事件發生時間的標準技巧分析第二段間隔時間。本文考慮以Kendall''s tau作為二元有序事件資料中兩間隔時間之相關性測度,並以設限時間的存活函數之倒數作為權重調整誘導訊息設限造成的偏差,建立二元有序間隔時間之Kendall''s tau的無母數估計量。運用U統計量的性質與平賭量的技巧,可以得到Kendall''s tau估計量的變異數為漸近常態。最後,經由模擬呈現本文所提供的估計量之估計表現。 In follow-up studies, bivariate event data are often encountered when subjects may experience two events with different or the same types. In analyzing bivariate event data, two types of time scale are considered in the literature: the times to events and the times between adjacent events. When the occurrence of during follow-up two events is in a chronological order, the gap time, defined as the time between adjacent events, is often of interest in the study. In the literature, measures of association between bivariate event times have been studied, but not yet for two serial gap times. In general, standard techniques for analyzing the times to events are inappropriate for analyzing the second gap time due to the presence of induced informative censoring. In this paper, Kendall''s tau is considered as a measure of association between gap times. Nonparametric estimation of Kendall’s tau for two serial gap times is proposed in which inverse probability of censoring weights is used to accommodate the bias from induced informative censoring. Asymptotic normality of the proposed estimator of Kendall''s tau is obtained by employing the theory of U statistics along with martingale techniques. Finally, the performance of the proposed method is illustrated by a simulation study. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/180798 |
顯示於: | 流行病學與預防醫學研究所 |
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ntu-98-R96842027-1.pdf | 23.32 kB | Adobe PDF | 檢視/開啟 |
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