I have a CRF with a series of questions which are to contain various blood results. I have been requested to add to each item another field: a drop-down list of units. This list needs to be pre-populated with a default unit, BUT needs to allow the entry of a blank value, because these fields will also have an ITEM_DISPLAY_STATUS of HIDE. They will all be revealed by a preceding 'Was the blood test done?' question.
I started by specifying a default value in the DEFAULT_VALUE column, and then adding a list of units to RESPONSE_OPTIONS_TEXT. So far, so good: the default value appears correctly in each field. However, if I answer 'Was the blood test done?' negatively, the units items remain in view because they are already populated, and I cannot clear them because there is no blank option in the RESPONSE_OPTIONS_TEXT pull-down.
I therefore added a leading comma to the RESPONSE_OPTIONS_TEXT and RESPONSE_VALUES so as to include a blank option, but this time, instead of simply including a blank value at the start of the list, the default value no longer pre-populates, even though it's still defined in the DEFAULT_VALUE column.
Annoyingly, the default values appear correctly in the Preview page when the CRF is first uploaded.
What's happening here? Why does the defined default value disappear just because I have added a blank to the start of the RESPONSE_OPTIONS_TEXT?
Is this a bug? Am I missing something? What other options do I have?