We are currently working on the forum. For the short-term, all forum content will be in read-only format. We apologize for the interruption and look forward to collaborating with you shortly. All the best in your research!

Why Extracting Data containing NULL values denoted by 'UNK' is being extracted as 'N'

Hi Cal/Folks
Greetings from New Zealand - I am extracting the data from OpenClinica using a dataset I created – I found that where the data value was ‘Unknown’ – it was being extracted as ‘N’ and not ‘UNK’. During setup of the Study Event definition – ‘UNK’ was selected to represent NULL values. (highlighted RED below)

Setup of Study Event Definition for Baseline CRF



Here is example of where ‘Unknown’ was selected for a data field viz. Previous Vascular disease (highlighted RED below) for subject 1001

Baseline Data Entry for Subject 1001



However when we extracted the data for the Baseline CRF – the store value for data field ‘Previous Vascular Disease’ for patient 1001 is ‘N’ – not ‘UNK’
Any ideas why ‘N’ is being extracted and no ‘UNK’ see excerpt of data extract

Excel Spreadsheet of Baseline Data Extract



Any ideas on why this maybe happening and how to resolve it will be much appreciated .

Thanking you in advance.
Kind Regards
Mervyn




"...If its not documented, it didn't happen... if its not signed, nobody did it..."

Comments

  • mervtynw28mervtynw28 Posts: 16
    Setup of Study Event Definition for Baseline CRF - http://tinypic.com/view.php?pic=352n238&s=8
  • mervtynw28mervtynw28 Posts: 16
    Baseline Data Entry for Subject 1001
    http://tinypic.com/view.php?pic=2wquxqr&s=8

    Excel Spreadsheet of Baseline Data Extract
    http://tinypic.com/view.php?pic=f2xki&s=8  
  • mervtynw28mervtynw28 Posts: 16
    Excel Spreadsheet of Baseline Data Extract
    http://tinypic.com/view.php?pic=f2xki&s=8
  • kristiakkristiak Posts: 1,340 ✭✭✭
    via Email
    Hi Mervyn,

    You have used the "Single Select" option for this variable. You screen print shows a value "Unknown". What code was assigned to this value in the spread sheet? The "UNK" that you selected during set up would only show up if you left the actual field blank (NULL)! But you have actually entered a value "Unknown" thus it is not NULL. To code a NULL value in the single select option you must use ,, as a value in the coding for blanks.

    Regards

    Krister
  • mervtynw28mervtynw28 Posts: 18
    via Email
    Hi Krister

    Many thanks for your response, I will definitely give that a try ie. set the field back to 'Select one' which should be equivalent to NULL and redo the data extract.



    I have attached copy of CRF setup spreadsheet below – you see that we have not set up a Option called ‘Unknown’ – not sure why it is appearing as an option on dropdown list – similarly there is no Response Value assigned for ‘Unknown’ in setup spreadsheet.



    Wondering if the select of ‘UNK’ for NULL values has added the ‘Unknown’ option to dropdown text field.



    [cid:[email protected]]





    Any input will be much appreciated.



    Many thanks for your assistance.

    Kind regards

    Mervyn



    Mervyn Wong | M.Sc.(Hons); PGDipCom.

    Information Systems Manager



    Working days: Mon-Tue



    "...If its not documented, it didn't happen... if its not signed, nobody did it..."
  • kristiakkristiak Posts: 1,340 ✭✭✭
    via Email
    Good luck. It should work as soon as OC does not see any data in the field, i.e. NULL
  • mervtynw28mervtynw28 Posts: 18
    via Email
    Hello
    I will be out of office from 18 Mar 2014 13:00 to 21 Mar 2014, otherwise, my office hours normally are 07:00-14:30 Mon and Tue, please contact Tracy Shuurman outside of these hours on 021 621 404 or [email protected]
    Many thanks
    Mervyn
This discussion has been closed.