Date: Thu, 20 Nov 2003 14:45:41 GMT LWn "SAS(r) Discussion" LWn Telia Internet Re: Calculating time to an event

Sean

I don't have a solution but at least an idea for a start. Since it looks like every weekvalue is a multiple of 26 I would start using Proc Transpose to get all values from each ID in the same record.

ID Score26 Score52 Score78 Score104 etc 1 20 20 17 . 2 15 . 18 . 3 12 . 16 15

thereafter a number of IF/THEN could do the rest. hope it helps a bit

/LWn

"Candrilli, Sean D." <scandrilli@RTI.ORG> skrev i meddelandet news:085D75F957E029479D75AD90F8A8F14B05822B@rtints3.rti.org... > Greetings Fellow SAS Users, > > I am new to the group, and have a question that I am hoping someone can > assist me with. I need to estimate a proportional hazards model, which is > the easy part. The difficulty lies in the data that I received. I having a > terrible time trying to get the data setup like it needs to be. > > I have something that looks like this: > ID Week Score > 1 26 20 > 1 52 20 > 1 78 17 > 2 26 15 > 2 78 18 > 3 26 12 > 3 78 16 > 3 104 15 > > My event of interest is a drop in score, and I need to model the DAYS > (notice that I don't have days here, but rather week of visit) to a drop in > score. To further complicate things, I need to do this for a 1-point drop, > a 2-point drop, etc, etc. With regards to censoring, for a censored term, > the time to the event would be the last day seen (which may differ across > respondents.) Unfortunately I have respondents that skipped visits (ID #3 > above did not come in for the week 52 visit.) > > For ID #1 above I think that the days to events should be as follows (each > 26 week block is set to 182 days): > days_1pt_drop = 182 + 182 + 60.7 = 424.7 > days_2pt_drop = 182 + 182 + 60.7 + 60.7 = 485.4 > days_3pt_drop = 182 + 182 + 60.7 + 60.7 + 60.7 = 546 > > and > cens_1pt_drop = 0 > cens_2pt_drop = 0 > cens_3pt_drop = 0 > > because clearly these events did happen for this ID. > > Now, for ID #2, who did not experience a decline in score, days should be as > follows: > days_1pt_drop = 546 > days_2pt_drop = 546 > days_3pt_drop = 546 > > because the last day this respondent was seen was on day 546 (78 weeks X 7 > days) > > and > cens_1pt_drop = 1 > cens_2pt_drop = 1 > cens_3pt_drop = 1 > > Ultimately I think that I need a file that looks like this: > > ID days_1pt days_2pt days_3pt cens_1pt cens_2pt cens_3pt > 1 424.7 485.4 546 0 0 0 > 2 546 546 546 1 1 1 > > > I apologize for dumping all of this here. I really do not have any idea how > to go about attacking this problem. If this isn't the appropriate forum for > something like this, and someone knows a more appropriate place to post > this, I would appreciate learning of it. > > Any thoughts or suggestions would be greatly appreciated. > > Kind Regards, > > Sean

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