Apprectiate your advise I have a dataset where i need new flag variable for sequential or combination therapy   Patient Treatment Start End   Flag             E1 A 10-Apr-17 26-Jun-17 Seq A E1 B 07-Jun-18 08-Aug-18 Seq A             E2 B 06-Sep-16 20-Oct-16 Seq B E2 A 15-Nov-17 04-Oct-18 Seq B             E3 A 07-Dec-10 08-Feb-11 Seq A E3 A 06-Sep-16 20-Oct-16 Seq A E3 B 15-Nov-17 04-Oct-18 Seq A             E4 B 07-Dec-10 08-Feb-11 Seq B E4 B 06-Sep-16 20-Oct-16 Seq B E4 A 15-Nov-17 04-Oct-18 Seq B             E5 A 27-Feb-18 20-Nov-18 Combi C E5 B 22-May-18 30-Oct-18 Combi C             E7 A 01-Feb-16 28-Apr-16 Seq A E7 A 20-Apr-17 16-May-17 Seq A E7 B 21-Aug-17 02-Jan-19 Seq A E7 A 27-May-19 29-Jul-19 Seq A             E8 B 01-Feb-16 28-Apr-16 Seq B E8 B 20-Apr-17 16-May-17 Seq B E8 A 21-Aug-17 02-Jan-19 Seq B E8 B 27-May-19 29-Jul-19 Seq B   treatment can be sequential (prev trt has ended before start of next trt) treatment can be combination (prev trt has not ended before start of next trt) If the patient has an end date for one prior therapy that occurs on or before the start date of another prior therapy, then assign A or B depending on which starts first Ex: scenarios 1,2,3 and 4 If the patient doesn’t have an end date for a prior therapy that occurs on or before the start date of another prior therapy, then assign C. Ex: scenario 5 Also, For scenarios 3 and 4, we take the min (start) and max (end) per treatment for comparing. For Ex: Patient E3, A trt has min (start) as 07-Dec-10 and max (end) as 20-Oct-16 which has ended before min(start) of B (15-Nov-17) However scenarios 5 and 6 we need to make few exceptions. when we take the min (start) and max (end) per treatment, they get flagged as combination although they are sequential For Ex: Patient E7, A trt has min (start) as 01-Feb-16 and max (end) as 29-Jul-19. So when code compares Trt A max(end) 29-Jul-19 with Trt B min(start) 21-Aug-17, it treats as A has not ended before start of B and hence flags as Combination. Similar for Patient E8. How to tell the program to make an exception and not count this as combination? It should be treated as sequential Similar exceptions should be made for A B B A, A B B A A etc   ... View more

Dear Community, I have the following dataset. I would like to have my output dataset to be such a way that the unique observations(location) should become my columns and require a count column to suggest the no of values.  Appreciate your inputs.   ID Location 101 UK 101 France 101 Other 102 UK 102 Spain 103 Other 104 UK 104 Other 105 Other   I want the dataset to look like   ID UK France Spain Other Count 101 Y Y   Y 3 102 Y   Y   2 103       Y 1 104 Y     Y 2 105       Y 1 ... View more