Close/hide a form, but not the case

How to close/hide a form once the form is submitted, without closing the case? We want to leave the case open because we will have multiple rounds of interviews, and we want to close/hide the form so that after filling a form, the user will only see open cases in the form and this will prevent the user from re-entering the data. So our case is that the census worker (user) goes to a list of households that we assigned, and asks them questions (fill the census form). All households will be censused every 6 months. Is there a way to keep the case (each household is a case) open for the follow-up censuses, and also hide the form once it is submitted for a household?

Are you familiar with form display conditions? You should be able to keep track of census status for each household and filter out the census form accordingly.

Yes, we use form display conditions. We for each round of census, we have a different census form, like "Census- round1", "Census- round2", and the we want to display a form when it is their round and when this form is not filled.

So for "Census- round1", the display condition is ./round = 2 and ./hideform != 1, where "hideform" is a hidden value I created. If the last question is answered, hideform = 1, else hideform = 0, to indicate whether a form is submitted. However the ./hideform != 1 part is not working and now the form displays even if it is submitted.

What we wanted is hiding the form while keeping the case open (for later rounds). Any suggestions would be appreciated!