window push version 10.0 window push set more on window push log using 11.5.Isoproterenol.log, replace window push * 11.5.Isoproterenol.log window push * window push * Perform a response feature analysis of the effect of race and dose of window push * isoproterenol on blood flow using the data of Lang et al. (1995). For window push * each patient, we will perform separate linear regressions of change in window push * blood flow against log dose of isoproterenol. The response feature that window push * we will use is the slope of each individual regression curve. window push * window push use C:\WDDtext\11.2.Long.Isoproterenol.dta, clear window push * window push * Calculate the regression slope for the first patient window push * window push regress delta_fbf logdose if id == 1 window push predict yhat window push scatter delta_fbf dose if dose!=0 & id==1 /// window push || line yhat dose if dose!=0 & id==1 /// window push , ylabel(0 5 10 15 20 25) /// window push ytitle(Change in Forearm Blood Flow) xscale(log) /// window push xlabel(10 20 30 60 100 150 200 300 400, angle(45)) /// window push xmtick(10(10)90 250 350) legend(off) window push more window push * Calculate regression slopes for each patient. window push * Reduce data set to one record per patient. window push * The variable slope contains the regression slopes; race window push * is included in the by option of the statsby command to to window push * keep this variable in the data file. window push * window push statsby _b, by(id race) clear : regress delta_fbf logdose window push list id _b_logdose race window push stripplot _b_logdose, over(race) boffset(-0.2) ysize(2) /// window push box(lwidth(medthick) barwidth(0.2)) /// window push scale(2.5) yscale(titlegap(-8)) /// window push xtitle(Slope: Change in Blood Flow per Unit Change in Log Dose) window push more window push * window push * Do ranksum test on slopes. window push * window push ranksum _b_logdose, by(race) window push more window push * window push * Do t tests comparing change in blood flow in blacks and whites at window push * different doses window push * window push use C:\WDDtext\11.2.Long.Isoproterenol.dta, clear window push sort dose window push drop if dose==0 window push by dose: ttest delta_fbf , by(race) unequal window push log close