anova response t / d|t / p|d|t /
Or you could redo your anova. (Be careful to notice how I have numbered the levels of the different terms).
test c|t d|c|t / p|d|c|t ---- gives test on pooled doctor and center term with patient as error term
test t / c|t d|c|t ---- gives test on treatment with pooling of doctor and center nested in treatment as error term
You could use -test- to get the results you desire:
After examining the above anova results some people would want to drop the clinic term.
anova response t / c|t / d|c|t / p|d|c|t /