What is informative censoring?

What is informative censoring?

Informative censoring occurs when participants are lost to follow-up due to reasons related to the study, e.g. in a study comparing disease-free survival after two treatments for cancer, the control arm may be ineffective, leading to more recurrences and patients becoming too sick to follow-up.

What does non informative censoring mean?

Random (or non-informative) censoring is when each subject has a censoring time that is statistically independent of their failure time. The observed value is the minimum of the censoring and failure times; subjects whose failure time is greater than their censoring time are right-censored.

What type of data can be censored?

There are three types of censored data; right censored, left censored, and interval cesored. Data for which the exact event time is known is referred to as complete data. In addition to the three types of censored data, there are also two ways in which censored data may be grouped; singly censored or multiply censored.

What is left and right censoring?

Right censoring occurs when a subject leaves the study before an event occurs, or the study ends before the event has occurred. Left censoring is when the event of interest has already occurred before enrolment.

How do you deal with right censoring?

Dealing with Right Censored Data

1. Cut off the end of the sample period earlier so as to minimize the amount of censored data.
2. Use up to the minute data which would include censored observations, but somehow estimate a stand in measurement or otherwise weight them differently.

What is the difference between truncation and censoring?

Truncation: An object can be detected only if its value is greater than some number; and the value is completely known in the case of detection. The main difference between censoring and truncation is that censored object is detectable while the object is not even detectable in the case of truncation.

What is the difference between right censoring and left censoring?

‘ Right censoring occurs when a subject leaves the study before an event occurs, or the study ends before the event has occurred. Left censoring is when the event of interest has already occurred before enrolment.

When does non-informative censoring take place?

Non-informative censoring occurs if the distribution of survival times (T) provides no information about the distribution of censorship times (C), and vice versa.

Which is a less restrictive form of random censoring?

So independent censoring is a less restrictive form of random censoring (where we would not be taking into account the survival profile by covariates). p. 42. Non-informative censoring occurs if the distribution of survival times (T) provides no information about the distribution of censorship times (C), and vice versa.

When does an observation need to be right censored?

In general, an observation is said to be right censored if the person was alive at study termination or was lost to follow-up at any time during the study. By right censoring, it is meant that the survival time is only known to exceed a certain value.

Which is an advantage of Type II censoring?

Type II censoring has the significant advantage that you know in advance how many failure times your test will yield – this helps enormously when planning adequate tests. However, an open-ended random test time is generally impractical from a management point of view and this type of testing is rarely seen.