Hello Gurus, I am having hard time to flag at least two consecutive visit records per subject as one: Ex: if ALTX3ULN is 1 for two/more consecutive visits, then first record should be FLAG as 'Y' for that subject. please see below data have and out needed (also attached as excel files). DATA HAVE SUBJNO VISMON SAMPDT TESTCODE ALTX3ULN 1 1 30NOV2005:00:00:00 SGPT_ALT 0 1 4 01MAR2006:00:00:00 SGPT_ALT 0 1 8 28JUN2006:00:00:00 SGPT_ALT 0 1 12 25OCT2006:00:00:00 SGPT_ALT 0 1 16 22FEB2007:00:00:00 SGPT_ALT 0 1 24 31OCT2007:00:00:00 SGPT_ALT 0 1 36 29OCT2008:00:00:00 SGPT_ALT 0 1 48 30SEP2009:00:00:00 SGPT_ALT 0 1 60 13OCT2010:00:00:00 SGPT_ALT 0 1 72 12OCT2011:00:00:00 SGPT_ALT 0 1 84 17OCT2012:00:00:00 SGPT_ALT 1 1 96 28OCT2013:00:00:00 SGPT_ALT 0 2 1 21NOV2005:00:00:00 SGPT_ALT 0 2 4 20FEB2006:00:00:00 SGPT_ALT 0 2 8 10JUL2006:00:00:00 SGPT_ALT 0 2 12 23OCT2006:00:00:00 SGPT_ALT 0 2 16 26FEB2007:00:00:00 SGPT_ALT 0 2 24 22OCT2007:00:00:00 SGPT_ALT 0 2 36 21OCT2008:00:00:00 SGPT_ALT 0 2 48 08OCT2009:00:00:00 SGPT_ALT 1 2 60 13OCT2010:00:00:00 SGPT_ALT 0 2 72 13OCT2011:00:00:00 SGPT_ALT 1 2 84 15OCT2012:00:00:00 SGPT_ALT 1 2 96 22OCT2013:00:00:00 SGPT_ALT 1 3 0 04NOV2005:00:00:00 SGPT_ALT 1 3 1 06DEC2005:00:00:00 SGPT_ALT 1 4 1 08DEC2005:00:00:00 SGPT_ALT 0 4 4 07MAR2006:00:00:00 SGPT_ALT 0 4 8 22JUN2006:00:00:00 SGPT_ALT 0 4 12 17OCT2006:00:00:00 SGPT_ALT 0 5 1 07DEC2005:00:00:00 SGPT_ALT 0 5 4 06MAR2006:00:00:00 SGPT_ALT 1 5 8 10JUL2006:00:00:00 SGPT_ALT 1 5 12 10NOV2006:00:00:00 SGPT_ALT 1 5 16 08MAR2007:00:00:00 SGPT_ALT 0 5 20 27JUN2007:00:00:00 SGPT_ALT 0 5 24 26OCT2007:00:00:00 SGPT_ALT 0 5 36 15OCT2008:00:00:00 SGPT_ALT 0 5 48 16OCT2009:00:00:00 SGPT_ALT 0 5 60 02NOV2010:00:00:00 SGPT_ALT 0 5 60 01NOV2011:00:00:00 SGPT_ALT 1 OUTPUT NEEDED SUBJNO VISMON SAMPDT TESTCODE ALTX3ULN FLAG 1 1 30NOV2005:00:00:00 SGPT_ALT 0 1 4 01MAR2006:00:00:00 SGPT_ALT 0 1 8 28JUN2006:00:00:00 SGPT_ALT 0 1 12 25OCT2006:00:00:00 SGPT_ALT 0 1 16 22FEB2007:00:00:00 SGPT_ALT 0 1 24 31OCT2007:00:00:00 SGPT_ALT 0 1 36 29OCT2008:00:00:00 SGPT_ALT 0 1 48 30SEP2009:00:00:00 SGPT_ALT 0 1 60 13OCT2010:00:00:00 SGPT_ALT 0 1 72 12OCT2011:00:00:00 SGPT_ALT 0 1 84 17OCT2012:00:00:00 SGPT_ALT 1 1 96 28OCT2013:00:00:00 SGPT_ALT 0 2 1 21NOV2005:00:00:00 SGPT_ALT 0 2 4 20FEB2006:00:00:00 SGPT_ALT 0 2 8 10JUL2006:00:00:00 SGPT_ALT 0 2 12 23OCT2006:00:00:00 SGPT_ALT 0 2 16 26FEB2007:00:00:00 SGPT_ALT 0 2 24 22OCT2007:00:00:00 SGPT_ALT 0 2 36 21OCT2008:00:00:00 SGPT_ALT 0 2 48 08OCT2009:00:00:00 SGPT_ALT 1 2 60 13OCT2010:00:00:00 SGPT_ALT 0 2 72 13OCT2011:00:00:00 SGPT_ALT 1 Y 2 84 15OCT2012:00:00:00 SGPT_ALT 1 2 96 22OCT2013:00:00:00 SGPT_ALT 1 3 0 04NOV2005:00:00:00 SGPT_ALT 1 Y 3 1 06DEC2005:00:00:00 SGPT_ALT 1 4 1 08DEC2005:00:00:00 SGPT_ALT 0 4 4 07MAR2006:00:00:00 SGPT_ALT 0 4 8 22JUN2006:00:00:00 SGPT_ALT 0 4 12 17OCT2006:00:00:00 SGPT_ALT 0 5 1 07DEC2005:00:00:00 SGPT_ALT 0 5 4 06MAR2006:00:00:00 SGPT_ALT 1 Y 5 8 10JUL2006:00:00:00 SGPT_ALT 1 5 12 10NOV2006:00:00:00 SGPT_ALT 1 5 16 08MAR2007:00:00:00 SGPT_ALT 0 5 20 27JUN2007:00:00:00 SGPT_ALT 0 5 24 26OCT2007:00:00:00 SGPT_ALT 0 5 36 15OCT2008:00:00:00 SGPT_ALT 0 5 48 16OCT2009:00:00:00 SGPT_ALT 0 5 60 02NOV2010:00:00:00 SGPT_ALT 0 5 60 01NOV2011:00:00:00 SGPT_ALT 1
... View more