Lower Bound for Target Variable Use this option to specify a variable whose values indicate whether or not the time-to-event variable values are right-censored. This variable must have values smaller than the values of the response (target) variable. Missing values for this variable will be converted to negative infinity, and the target variable will be considered right-uncensored. To Specify a Lower Bound for the Target Variable: Specify the Input SAS Data Set. All of the variables in the specified input data set are displayed in the Available Variables field. Examine the list of available variables. Highlight the desired variable. Click to add the highlighted variable to the Lower Bound for Target Variable field.