A quick way to ensure that the data were entered correctly is to count the number of rows with data.If there is no intrinsic order, they can be arranged in any order Ensure that the progression of column A to column B to column C follows the natural order of the groups. For example, if the treatment groups are intrinsically ordered (for example, increasing dosages) maintain that order when entering data. It’s recommended to take advantage of known relationships in the data to help keep the data organized properly.For example, the data above, could also be entered like this:
As long as the correct elapsed time is associated with the correct outcome (1 or 0) in the correct group (column) on the same row, the analysis results will be the same. However, note that there’s no reason that the groups have to be separated this way. For example, if the first 10 rows correspond to members of a control group, while the next 10 rows correspond to members of a treatment group, the data may look something like this: Each row should contain a value in only one Y column. Enter subjects belonging to different treatment groups into different Y columns (one Y column for each group).Any row without a 1 or 0 in any Y column will be omitted from the analysis Note that every row must have either a 0 or a 1 in a single Y column. Enter “0” into rows where the subject was instead censored at this time. Enter “1” into the Y column for rows in which the subject experienced the event of interest at the time or end date shown in the X column.Optionally, row titles can be used to identify each subject/participant.Prism will calculate the difference between these two dates as the elapsed observation time for the observation For this option, a calendar date must be entered for the starting (zero) time and ending time for each observation. Note that these are elapsed times, and so time zero does not need to be specified For this option, use any convenient unit, such as days or months. ▪ Enter elapsed time as number of days (or months…). Note that if starting with your own data, Prism offers two choices for entering elapsed times: Enter the time until censoring or the event of interest (death, or whatever other event you’re tracking) in the X column.Enter the survival timesĮnter the elapsed time to the event of interest for each subject on a separate row in the table, following these guidelines: If you aren’t ready to enter your own data yet, choose “Start with sample data to follow a tutorial” and select one of the tutorial data sets. Create a survival data tableįrom the Welcome or New Table dialog, choose the Survival tab. To learn more about the background and mathematics involved in the analysis that Prism performs, check out this section of the guide. This page describes the steps necessary to perform Kaplan-Meier survival analysis within Prism.
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