* Prostate Cancer --- Baseline data;

DATA baseline;

*INFILE "C:\Documents and Settings\kmed\My Documents\PrCa_cases.txt" ;
INFILE "Macintosh HD:Courses:613(StatSoftware):PrCa_cases.txt" ;

INPUT id t_0 MMDDYY8. psa_0 tx $ ;

RUN;


* Prostate Cancer --- Post-treatment PSA values ;

DATA post_tx;

*INFILE "C:\Documents and Settings\kmed\My Documents\psa_file.txt"
        linesize = 189 ;
 INFILE "Macintosh HD:Courses:613(StatSoftware):psa_file.txt"
        linesize = 189 ;
INPUT id 1-8 +1 (t_1-t_20) (MMDDYY8. +1 ) / +9 (psa_1-psa_20) (8.1 +1)  ;
RUN;

proc sort data=baseline; by id;
proc sort data=post_tx;  by id;

data all; keep id time psavalue;
  merge baseline post_tx; by id;

  Array t(24) t_1-t_24; array psa(24) psa_1-psa_24;

  array fu_time(24) fu1-fu24;

  do i=1 to 24; fu_time(i) = t(i) - t_0;

    psavalue= psa(i);

    time = fu_time(i);

   if psavalue ne . then output;

  end;

run;



proc sort data=all; by id;
proc plot; plot psavalue*time; by id;
run;