Avoid Leads Slipping Through the cracks

I love Podio but the one feature my previous CRM had was this:

Every lead must have an action or task tied to it. In other words, you could not complete a task without assigning the next task for that lead. This is crucial to me because it prevents the potential human error of forgetting to set the next task (ex. Follow up in 30 days) therefore the lead may never get attention again as it is 1 lead lost among 5000 leads.

I don’t need exactly this but I was hoping that the filter option had something that could show all items that don’t have a task assigned. (Basically a view of all leads where the next follow up was forgotten to be added) (in my business if there is no next follow up date, the lead is basically dead).

The only thing I could think of is to create a new field with two options: 1. Next action set 2. Not set. Then use the filter to see what leads have a task assigned. I don’t love this option as again, human error could mess this up. (They could forget to update this field then the action set status is inaccurate)

Any help would be much appreciated.