The mistake you are making is the declaration of the Age text as a macro, by enclosing it in the macro symbols. In fact, Age is just a text, it is not declared as a local macro with the loc command. The correct is given below.
clear set obs 100 gen mean_age = int(uniform() * 100) gen stupd = mod(_n,2) ttest mean_age, by(stupd) *Get the relevant statistics loc obs1 = `r(N_1)' loc obs2 = `r(N_2)' loc mean1 = `r(mu_1)' loc mean2 = `r(mu_2)' loc dif = `mean1' - `mean2' loc stde = `r(se)' loc pval = `r(p)' dis `dif' sum mean_age if stupd == 0 loc max1 = `r(max)' loc min1 = `r(min)' sum mean_age if stupd == 1 loc max2 = `r(max)' loc min2 = `r(min)' *Write these with asdoc using the row option asdoc, row(Age, `obs1', `obs2', `min1', `max1', `min2', `max2', `mean1', `mean2', `dif', `stde', `pval') replace
