I have about 200,000 records of cases and I want to identify the true consecutive Negative result (can't have Positive result after it).  Here's some examples: A: Keep only the result after first two positive (Obs 3-5) B: Obs 6-7 need to be drop because these is a Positive after these Negative. C: Need to be drop 😧 Only 15-17 can be keep since 13 have Positive after them as well.   The basic concept is to keep the Negative results after the last positive for each case (group?) and give them a seq# if possible. Thank you so much for your help. I tried to add seq# but many times it starting with 2 or even 4 when I use if first.Case then Seq+1; Obs Case Test Date Test Result Record Wanted Seq# 1 A 01/01/2020 Missing 　 　 2 A 01/02/2021 Positive 　 　 3 A 01/03/2021 Negative V 1 4 A 01/04/2021 Negative V 2 5 A 01/05/2021 Negative V 3 6 B 01/01/2020 Negative     7 B 01/02/2021 Negative     8 B 01/03/2021 Positive     9 C 01/02/2021 Missing 　 　 10 D 01/01/2020 Positive     11 D 01/02/2021 Positive     12 D 01/03/2021 Missing     13 D 01/04/2021 Negative     14 D 01/01/2021 Positive     15 D 01/02/2022 Negative V 1 16 D 01/03/2022 Negative V 2 17 D 01/04/2022 Negative V 3 ... View more

I want to create a variable that can count how many "Yes" for each person/record. Is there a better way to do it? My data set actually have more than 3000 records......  Thank you so much!     Name Q1 Q2 Q3 Q4 Q5 Yes_count 1 Danny Yes Yes No No No   2 Mary Yes No Yes Yes Yes   3 John Yes Yes Yes Yes No   4 Lisa No Yes Yes Yes Yes   5 Mike No Yes No No Yes   6 Philip Yes Yes Yes Yes No   7 Sui Yes Yes No No Yes   8 Zack No Yes No Yes No   9 Pam Yes Yes No No Yes   10 William No No Yes No Yes   ... View more