trarrWe're using SAS 9.3 We have a dataset with a series of hearing test scores, sorted by patient ID, ear (left or right) and test date. For each patient, we need to find exams in which the test result, measured in decibels, was better (i.e. lower) than any prior exam by 10dB or more per patient, per ear. For example, Patient X has had 7 exams in his left ear in and the original data record would look like this: Patient Ear Date Measurement (dB) X Left Date1 10 X Left Date2 15 X Left Date3 26 X Left Date4 10 X Left Date5 20 X Left Date6 35 X Left Date7 10 I want to know, for each exam, if any of the prior exams were worse by at least 10dB. To do this, I will probably want to figure out what the max of the prior exams was and the difference between the recorded result and that maximum for each exam. Patient Ear Date Meaurement (dB) Max of prior exams Difference Improvement X Left Date1 10 -- -- -- X Left Date2 15 10 5 No X Left Date3 26 15 11 No X Left Date4 10 26 -16 Yes X Left Date5 20 26 -6 No X Left Date6 35 26 9 No X Left Date7 10 35 -25 Yes I tried doing this using Proc Transpose and the Max command in subsequent data step but each patient can have up to 22 tests, with some having just a few tests and some having as many as 22 tests performed, so this method seems cumbersome. It seems I should be able to do this with an array but I can't figure out all the steps. I can't figure out how to get the max of previous tests for each additional test performed rather than just getting the max of all the tests performed. Any help with this would be greatly appreciated, even if just to get in the right direction. Cheers, Jessica
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