Censoring and Truncation
Time-to-event data present themselves in different ways which create special problems in analyzing such data. One peculiar feature, often present in time-to-event data, is known as censoring, which, broadly speaking, occurs when some lifetimes are known to have occurred only within certain intervals. The remainder of the lifetimes are known exactly. There are various categories of censoring, such as right censoring, left censoring, and interval censoring. Right censoring will be discussed in section 3.2. Left or interval censoring will be discussed in section 3.3. To deal adequately with censoring in the analysis, we must consider the design which was employed to obtain the survival data. There are several types of censoring schemes within both left and right censoring. Each type will lead to a different likelihood function which will be the basis for the inference. As we shall see in section 3.5, though the likelihood function is unique for each type of censoring, there is a common approach to be used in con tructing it.
KeywordsCounting Process Death Time Interval Censoring Random Censoring Sacrifice Time
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