**** Read in the dataset use "http://biostat.mc.vanderbilt.edu/wiki/pub/Main/CourseBios312/prostaticcancer.dta", clear * Set the outcome stset time status * Kaplan-Meier Plot sts graph, by(treatment) * List the observations list time status if treatment==2 di 15/16 * K-M estimate will be 1 up to time 32 ,and 0.9375 after that time sts test treatment * Treatment: Classical and Robust standard errors stcox treatment stcox treatment, robust * Index stcox index, nohr stcox index stcox index, robust