retain the non missing previous value and compare the values between the variables

[SrikanthY]

retain the date1 value for the same subject and compare with date2. and for vistis also..

condition1 if dates are matching and visits are not matching then visit missmatch.

condition2 if visits are matching and dates are not matching then date missmatch.

condition3 if single subject then flag as present in date1 or date2 vice versa.

condition 4: for multiple rows (ex:A1017, A1029) should compare only if dates or visits are matching other wise apply condition3.

Input dataset

SubID	Date1	Visit1	Visit2	Date2
A1003	4-Sep-17	week 45
A1003			Unscheduled	4-Sep-17
A1005			Week 65	3-Apr-17
A1006			Early Discontinuation	20-Oct-17
A1009	28-Aug-17	Discont
A1009			Visit 20 or Early Withdrawal	28-Aug-17
A1009			Unscheduled	28-Aug-17
A1011			Discont	25-Oct-17
A1011			Week 78	8-Jun-17
A1017	21-Aug-17	Discont
A1017			Unscheduled	21-Aug-17
A1017			Week 65	11-Oct-17
A1020			Week 45	5-Apr-17
A1020	6-Apr-17	Week 45
A1021	12-Oct-17	Unscheduled
A1021			Week 24	12-Oct-17
A1021	5-Oct-17	Week 24
A1025			Week 7	20-Oct-17
A1029			Unscheduled	29-Apr-16
A1029			Unscheduled	7-Dec-15
A1029	29-Apr-16	Week 13

output dataset

SubID	Date1	Visit1	Visit2	Date2	date_missmatch	Visit_missmatch	absent in date1	absent in date2
A1003	4-Sep-17	week 45	Unscheduled	4-Sep-17		yes
A1005			Week 65	3-Apr-17			yes
A1006			Early Discontinuation	20-Oct-17			yes
A1009	28-Aug-17	Discont	Week 10	28-Aug-17		yes
A1009	28-Aug-17	Discont	Unscheduled	28-Aug-17		yes
A1011			Discont	25-Oct-17			yes
A1011			Week 78	8-Jun-17			yes
A1017	21-Aug-17	Discont	Unscheduled	21-Aug-17		yes
A1017			Week 65	11-Oct-17			yes
A1020	6-Apr-17	Week 45	Week 45	5-Apr-17	yes
A1021	12-Oct-17	Unscheduled	Week 24	12-Oct-17		yes
A1021	5-Oct-17	Week 24	Week 24	12-Oct-17	yes
A1025	Week 7	20-Oct-17						yes
A1029	29-Apr-16	Week 13	Unscheduled	29-Apr-16		yes
A1029			Unscheduled	7-Dec-15			yes

[andreas_lds]

What is the question?

[SrikanthY]

Please check the required output. from the provided input data.

want to flag inconstant dates and visits.

[Patrick]

@SrikanthY

1. Post your input data via a valid SAS data step creating a SAS table

2. Please don't expect people to do all the work for you. What have you done so far? Eventually post your not yet fully working code and some explanation of your approach.