Overview
For use with SAS Version 9.x.
The TVEM SAS macro estimates coefficients in a time-varying effect model. Traditional analytic methods assume that covariates have constant (i.e., time-invariant) effects on a time-varying outcome. The %TVEM macros are able to estimate the time-varying effects of covariates. The %TVEM macro suite includes convenient tools for the analysis of intensive longitudinal data.
The %TVEM Macro Suite includes
%TVEM_normal for normally distributed outcomes
- %TVEM_logistic for logistic-distributed outcomes
- %TVEM_poisson for Poisson-distributed outcomes
- %TVEM_zip for outcomes with zero-inflated Poisson models, and
- %GLIMMIX for generalized mixed effects models1.
Features of all TVEM SAS macros include
- ability to handle complicated models
- generation of plots for estimated coefficient functions
- parameter estimates saved to SAS data file
- ability to specify covariates that have constant effects or time-varying effects, and
- accommodation different distributions (normal, logistic, Poisson, or zero-inflated Poisson) outcomes measured over time.
- Option to plot odds ratios and 95% confidence bands for logistic distributions - New in version 2.1
- Substantial revision of the plots produced by the macros - New in version 2.1
Recommended Citations
TVEM SAS Macro Suite (Version 2.1.0) [Software]. (2012). University Park: The Methodology Center, Penn State. Retrieved from http://methodology.psu.edu
Yang, J., Tan, X., Li, R., & Wagner, A. (2012). TVEM (time-varying effect model) SAS macro suite users' guide (Version 2.1.0). University Park: The Methodology Center, Penn State. Retrieved from http://methodology.psu.edu
1This macro was developed by SAS Institute Inc. It is automatically called by the %TVEM macros when needed.
Need Help?
If you have questions or comments about the macro, please email MChelpdesk@psu.edu.
If your organization does not permit download and installation of files, please contact us with a shipping address and we will provide a CD containing all downloadable files.