The GFORMULA macro implements the parametric g-formula in SAS to estimate the risk or the mean of an outcome under sustained treatment strategies specified by the user.
Authors: Roger W. Logan, Jessica G. Young, Sarah Taubman, Yu-Han Chiu, Sara Lodi, Sally Picciotto, Goodarz Danaei, Miguel A. Hernán
Version 3.1 July 2021. This version includes options and improvements that are not compatible with previous versions of the software. For questions and comments, email rwlogan@hsph.harvard.edu
Version 3.2 Sept 2021. This version includes fixes for negative knots in splines and corrects the issue of cumavg ptypes being includd twice in some model lists. For questions and comments, email rwlogan@hsph.harvard.edu
Version 4.0 April 2022. This version includes changes for the use of a censoring variable in estimation of the natural course and calculations of the average intervened on. For questions and comments, email rwlogan@hsph.harvard.edu.