* Adapted from programs found here https://www.hsph.harvard.edu/miguel-hernan/causal-inference-book/ ; /*************************************************************** PROGRAM 14.1 Preprocessing, ranks of extreme observations, IP weights for censoring Data from NHEFS ***************************************************************/; libname causinf "V:\sismid2016"; /* some preprocessing of the data */ data nhefs; set causinf.nhefs_book; if .