1 Reply Latest reply on Sep 7, 2018 1:12 PM by Joe Oppelt

    DateDiff between two values

    Yin Chang

      Hi there,


      I am struggling with my datediff calculation. I have a dataset where there are test results performed for patients who test on multiple occasions (the number is not consistent between individuals). I need to calculate the difference in dates between two result values: "Non-reactive" to "Reactive" and then "Reactive to Non-reactive".


      So far, I was able to use this calculation for date difference between sample collections:

      DATEDIFF('day',LOOKUP(ATTR([Collection Date]),0),LOOKUP(ATTR([Collection Date]),1))


      This generates the correct difference in dates when I place the patients and samples together; however, I get the date difference of the next patient as well when I only need the difference between one patient's samples.


      So, 1) how can I resolve this above issue and 2) how can I include the result values in the calculation so I'm only looking at the date difference between either "Non-reactive" to "Reactive" or "Reactive to Non-reactive"?


      Appreciate any help with this!


        • 1. Re: DateDiff between two values
          Joe Oppelt

          You'll need to upload a workbook so we can work together.


          You can set the table calc settings so that they restart every [PatientID], and that will stop looking forward at the end of a patient's rows.  I could show you if I had a workbook.


          As for the reactive vs non-reactive, I would really need to see a workbooks so I can see how the data is set up.