No there isnt. A "0" and a blank cell mean two different things. A "0" is actual data. It might be a variable to an answer, or an indication that this question has not been answered yet.

A blank cell means that this question is not being accessed at all in your questionnaire. This might be because the target group only allows for certain questions to show, or because of all the area's that need to be visited during an ATP check, only a random few are selected.

But what about columns like med_spec? They are not part of my questionnaire selection, yet show a "0" in all cases I run an export?

This is because these pages are always accessed, even though you don't see them. A programming choice has been made to always land on this page, yet these pages have been made "invisible". The system recognises these questions being accessed, but since they are invisible, you can't enter data, hence they pop up as a "0" in your export.

This does not influence your reporting.