I know what is going on. You are using low version SAS 9.3. Try this one .
data x;
y="All patient"||'0D0A'x||" (n=XX:xx vs n=YY:yy) ";x=1;output;
y="Group1 vs Group4"||'0D0A'x||" (n=XX:xx vs n=YY:yy)"; x=2;output;
run;
proc sgplot data=x;
scatter x=x y=y;
run;
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