Date:         Thu, 29 May 2008 18:48:20 -0700
Reply-To:     "HXDAIC@gmail.com" <HXDAIC@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "HXDAIC@gmail.com" <HXDAIC@GMAIL.COM>
Organization: http://groups.google.com
Subject:      Dynamic randomization remove aribitary assignment treatment A
Comments: To: sas-l@uga.edu
Content-Type: text/plain; charset=ISO-8859-1

Hi there,

Following code I came up to dynamically assign treatment A or B to
subjects and make sure  balance treatement between same fact.
Although it can work but the problem is that it is always arbitary
assign treatment A first if number of treatment  A = number of
Treatment B in same fact.

data a;
 do i=1 to 300;
  do fact = mod ((i+ int(ranuni(0)*100)), 6); /*fact 0-5*/
  output;
  end;
 end;
run;

data b;
 array V V0-V5;
 array VA VA0-VA5;
 array VB VB0-VB5;
 set a;
     retain V0-V5 0 ;
  retain VA0-VA5 0 ;
  retain VB0-VB5 0 ;
  do k = 1 to dim(v);
        if k=(fact+1) then do;
   V[k] = 1+ V[k];
    TREATMENT= ifC((VA[k] LE VB[k]), 'A', 'B')  ;
   VA[k]=ifn((VA[k] LE VB[k]), VA[k]+1, VA[k]+0)  ;
       VB[K]=V[k]-VA[k];
  end;
  end;
 run;



Q1:  How to randomly assign treatment when No. of A already = No. of B
in same fact.

Q2:  How to balance the total number of A and B at same time in
subjects.

Q3 : Is this follow the  dynamic randomization rule?

Thanks in advance.