A rule processing method includes defining {HEAD ~ a target group} of patients chosen from a group of {TAIL ~ existing patients} 
A rule processing method includes defining { HEAD ~ a target group } of patients chosen from a group of { TAIL ~ existing patients }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL