Hi all, I wonder if you can please help me on something that has got me stuck over the whole of last week! I have visit information for a large number of patients. Every patient has a varying number of visits and visit date. The task is to classify the current medication treatment they have been prescribed by their doctor by looking ahead over the next 6 months and considering what else they may have got prescribed in the future (of next 180 days). For simplicity of describing this example, think of it whether we classify this as a concurrent medication or not - depending if they have prescribed anything else in the future also. So I am really stuck how to do this - there is a large number of patients, a large number of records for each - some patients visited nearly every day, others once every 8 months. The information goes up to a few years for each. So it's tricky to set any hardcoded rules for them, or indeed to just look at next few observations. Here is an example of what the data looks like. So for this example, we want to know if Patient1 was prescribed anything else over next 180 days other than drug x, which would then allow us to create a new variable indicating that "drug x" was given as a concurrent medication. ny example codes on how to solve this would be massively appreciated. Visit_date Max_date Trt_at_visit Patient1 01/12/00 30/05/01 Drug_x Patient1 31/12/00 29/06/01 Drug_x Patient1 24/03/01 20/09/01 Drug_e Patient1 22/07/01 18/01/02 Drug_x Patient1 02/12/00 31/05/01 Drug_x Patient1 01/01/01 30/06/01 Drug_x Patient1 25/03/01 21/09/01 Drug_x Patient1 23/07/01 19/01/02 Drug_x Patient1 20/11/01 19/05/02 Drug_a Patient1 20/12/01 18/06/02 Drug_x Patient1 13/03/02 09/09/02 Drug_x Patient1 11/07/02 07/01/03 Drug_x Patient1 08/11/02 07/05/03 Drug_x Patient1 08/12/02 06/06/03 Drug_x Patient1 01/03/03 28/08/03 Drug_x Patient2 29/06/03 26/12/03 Drug_x Patient2 27/10/03 24/04/04 Drug_e Patient2 26/11/03 24/05/04 Drug_x Patient2 17/02/04 15/08/04 Drug_x Patient2 16/06/04 13/12/04 Drug_x Patient2 14/10/04 12/04/05 Drug_e Patient2 13/11/04 12/05/05 Drug_x Patient2 04/02/05 03/08/05 Drug_x Patient2 04/06/05 01/12/05 Drug_x Patient2 02/10/05 31/03/06 Drug_x Patient2 01/11/05 30/04/06 Drug_x Patient2 23/01/06 22/07/06 Drug_x Patient2 23/05/06 19/11/06 Drug_x
... View more