Kaplan-Meier analysis allows a description of the behaviour of a binary variable over time. The Kaplan-Meier method determines the number of patients included in one modality at the beginning of the study passing to the other modality over time. The resulting chart displays step-shaped curves.
Kaplan-Meier curves are often used to describe the number of death’s evolution over time in medical research, but it can be used for all statistics that could be divided in two categories of interest and have measures over time. For example, the variable “pain level below 3” taking the modalities “yes” or “no”, measured each day of the week, is a dichotomous variable that can be described with a Kaplan-Meier curve over time.
To test the difference between groups based on the Kaplan-Meier curves a Log-rank test is usually performed.
How to use it on EasyMedStat?
Which data is required?
In order to perform a survival analysis (Kaplan-Meier), you need 3 dates for each of your patients:
- Date of inclusion: the date at which the analysis will start
- Date of event: the analyzed event
- Date of last follow-up: the date at which the patient is not followed anymore