- Select one variable with survival times (for example, number of weeks surviving).
- Select two variables containing the start and end dates respectively.
- Select six variables containing dates.
Specifically, these variables should contain the month (1 to 12), day (1 to 31), and year when the particular observation began (for example, when the patient was admitted to the hospital), and the month, day, and year when the observation was terminated (due to death or failure or censoring, for example, when a patient was dismissed from the hospital). While processing the data, Survival Analysis computes the number of days that elapsed between dates and perform the analysis on this measure.
Note: If the value of the year is less than 100, Statistica automatically assumes that the year refers to the 20
th century; for example, the year 88 is converted to 1988