The SURVEYPHREG Procedure
- Overview
- Getting Started
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Syntax
PROC SURVEYPHREG Statement BY Statement CLASS Statement CLUSTER Statement DOMAIN Statement ESTIMATE Statement FREQ Statement LSMEANS Statement LSMESTIMATE Statement MODEL Statement NLOPTIONS Statement OUTPUT Statement Programming Statements REPWEIGHTS Statement SLICE Statement STORE Statement STRATA Statement TEST Statement WEIGHT Statement -
Details
Notation and Estimation Failure Time Distribution Time and CLASS Variables Usage Partial Likelihood Function for the Cox Model Specifying the Sample Design Missing Values Variance Estimation Domain Analysis Hypothesis Tests, Confidence Intervals, and Residuals Output Data Sets Displayed Output ODS Table Names ODS Graphics
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Examples
- References
| STRATA Statement |
- STRATA variables < / option > ;
The STRATA statement names variables that form the strata in a stratified sample design. The combinations of levels of STRATA variables define the strata in the sample, where strata are nonoverlapping subgroups that were sampled independently.
If your sample design has stratification at multiple stages, you should identify only the first-stage strata in the STRATA statement. See the section Specifying the Sample Design for more information.
If you provide replicate weights for BRR or jackknife variance estimation with a REPWEIGHTS statement, you do not need to specify a STRATA statement.
The STRATA variables are one or more variables in the DATA= input data set. These variables can be either character or numeric, but the procedure treats them as categorical variables. The formatted values of the STRATA variables determine the STRATA variable levels. Thus, you can use formats to group values into levels. See the discussion of the FORMAT procedure in the Base SAS Procedures Guide and the discussions of the FORMAT statement and SAS formats in SAS Formats and Informats: Reference. Strata variables must not occur in the CLASS statement.
The STRATA statement in PROC SURVEYPHREG is different from the STRATA statement in PROC PHREG ( Chapter 66, The PHREG Procedure ). PROC PHREG fits different baseline hazard functions in different strata, which is useful if the proportional hazards assumption is not satisfied.
You can specify the following option in the STRATA statement after a slash (/):