On Sep 1, 6:07 am, "cat.." <cat....@gmail.com> wrote: > Hi! > > I would try this: > > proc sort data = example; by pt visit; > > data locf; > set example; > by pt visit; > pvisit = lag(visit); > plabstd = lag(labstd); > if not first.pt then do; > if visit ne pvisit + 1 then do; > visit = pvisit + 1; > labstd = plabstd; > output; > end; > end; > drop pvisit plabstd; > run; > > but cannot test it. > > Regards, > > Catherine. > > On Aug 31, 7:42 pm, sas...@gmail.com wrote: > > > Dear, > > > Say for example if i am having 6 visits per patient, and i want to > > determine if any patient is missing any visit out of this 6, then i > > have to create an extra record for the missing visit, then how should > > i do that? Also i need to do a LOCF from the previous visit if the > > current visit is missing. > > > Example > > PT visit labstd > > 101 1 0.1 > > 101 2 0.1 > > 101 3 0.1 > > 101 5 0.1 > > 101 6 0.1 > > > If in the above example say visit 4 is missing, then i have to carry > > over all the data from the previous visit 3. Can someone tell me how > > can i do that? > > > Regards,

Hi,

Actually i have a data with around 100+ variables in it. And i need to make sure that there should be atleast 6 visits per patient. So if in case a patient is missing any visit, then i need to create a visit which is missing and then carry over the data from the previous visit for all the variables except few variables. I have two variables in the dataset named flag and ontreatment. So if a patient is missing any visit, i have to create a record for the missing visit, and carry over all the data from the previous visit for most of the variables, only where flag = 1 and ontreatment = 1. Example:

Patient visit FLAG ontreatment ecogscore OC_LOCF tumormeasurements investi daysofstudy plannedday 101 -1 3 OC 20 101 0 2 OC 20 101 1 1 1 4 OC 30 101 1 1 3 OC 30 101 2 1 1 4 LOCF . 101 3 1 1 2 OC 34 101 4 1 1 2 LOCF . 101 5 1 1 2 LOCF . 101 6 1 1 2 LOCF .

So there are character and numeric variables both in the dataset whose value needs to be carry over. In the above example, for patient 101, its missing visit 2, 4 5 and6. So i have to carry over data from the visit 1 for visit 2 where flag = 1and ontreatment = 1 for all the variables except the tumormeasurements. For visit 4, 5 and 6, carry over the data from the visit 3 where flag = 1 and ontreatment = 1 for all variables except the tumor measurements. That's the reason the tumor measurements values are missing for the LOCF records.

I would really appreciate if you can let me know how i can implement the above LOCF. Just want to remind again that there are more than 100 variables in the dataset and they are both character and numeric.

Regards,