What do Kaplan-Meier graphs show?
What do Kaplan-Meier graphs show?
The Kaplan-Meier estimator is used to estimate the survival function. The visual representation of this function is usually called the Kaplan-Meier curve, and it shows what the probability of an event (for example, survival) is at a certain time interval.
What does it mean when Kaplan-Meier curves cross?
If the Kaplan-Meier survival curves cross then this is clear departure from proportional hazards, and the log rank test should not be used. This can happen, for example, in a two drug trial for cancer, if one drug is very toxic initially but produces more long term cures.
What does censored mean in survival analysis?
Censoring is a form of missing data problem in which time to event is not observed for reasons such as termination of study before all recruited subjects have shown the event of interest or the subject has left the study prior to experiencing an event. Censoring is common in survival analysis.
What does it mean when a patient is censored?
Definition. A patient is scored as censored if he or she did not suffer the outcome of interest. In survival analysis, patients who do not have an “ event” during a specified period are said to have censored observation.
What does censoring mean in survival analysis?
What is left and right censoring?
Left censoring – a data point is below a certain value but it is unknown by how much. Interval censoring – a data point is somewhere on an interval between two values. Right censoring – a data point is above a certain value but it is unknown by how much.
How do you handle censored data?
Dealing with Right Censored Data
- Cut off the end of the sample period earlier so as to minimize the amount of censored data.
- Use up to the minute data which would include censored observations, but somehow estimate a stand in measurement or otherwise weight them differently.