/*creating ipdpower logs for journal article*/ version 13.1 ssc install ipdpower, replace //disable pause set more off //clear memory clear //set display line size //set linesize 90 /*opening log 0*/ //capture sjlog close //sjlog using ipdpower0, replace /*calling ipdpower: 1000 replications, total patient size of 5000, 20 higher level units (e.g. studies) , no heterogeneity at any level, analysed with xtreg (i.e. model assuming existence of RE for intercept)*/ ipdpower, sn(1000) ssl(5000) ssh(20) b0(1) b1(0.5) b2(0.3) b3(0.1) model(2) xnodts seed(7) //sjlog close, replace /*opening log 1*/ //capture sjlog close //sjlog using ipdpower1, replace /*calling ipdpower: as in log 0 but with random effect variance (heterogeneity) for exposure*/ ipdpower, sn(1000) ssl(5000) ssh(20) b0(1) b1(0.5) b2(0.3) b3(0.1) tsq1(0.5) model(2) xnodts seed(7) //sjlog close, replace /*opening log 2*/ //capture sjlog close //sjlog using ipdpower2, replace /*calling ipdpower: as in log 1 but with extreme skew distribution for errors (and hence outcome)*/ ipdpower, sn(1000) ssl(5000) ssh(20) b0(1) b1(0.5) b2(0.3) b3(0.1) tsq1(0.5) model(2) derr(xsknorm) xnodts seed(7) //sjlog close, replace /*opening log 3*/ //capture sjlog close //sjlog using ipdpower3, replace /*calling ipdpower: as in log 2 but analysis with xtmixed (instead of xtreg) assuming a fixed common intercept, random treatment effects and fixed effect for the covariate*/ ipdpower, sn(1000) ssl(5000) ssh(20) b0(1) b1(0.5) b2(0.3) b3(0.1) tsq1(0.5) model(3) derr(xsknorm) xnodts seed(7) //sjlog close, replace /*opening log 4*/ //capture sjlog close //sjlog using ipdpower4, replace /*calling ipdpower: as in log 3 but analysis with xtmixed assuming fixed study specific intercepts, random treatment effects and fixed study specific effect for the covariate (which is usually the recommended model for performing individual patient data meta-analysis)*/ ipdpower, sn(1000) ssl(5000) ssh(20) b0(1) b1(0.5) b2(0.3) b3(0.1) tsq1(0.5) model(4) derr(xsknorm) xnodts seed(7) //sjlog close, replace