Adding a bool column; tracking untouched vs. false
In most DBMSs, or at least the ones I have dealt with, a Bool is really a trinary.  You have 1, 0 and NULL.  NULL is specifically there for "I haven't entered any data yet."  Depending on how you code it your checkbox should default to unchecked for 0 or NULL.  Then 1 for checked of course.  However in your reporting you can actually differentiate between rows where someone has looked at it and entered a value (1 or 0) and rows where no one has updated it yet (rows where the value is NULL).