Customizable field attached to CTA for eason for failure or how CTA was closed

Would like to be able to identify the reason for the CTA failure/fire (why did the condition occur - example "customer did not know how to....") or how the CTA was closed, especially if the CTA closure was not resolved positively.  This would allow us to do statistical analysis on the reasons.
Can you capture that data in the status?   We have the following options for the status:  open, in progress, closed won, closed lost and completed.   An example would be, CTA is Invite Customer to Pre-Release program with a reason code of pre-release.  If the customer declines, we close it as closed lost.  I do my annalists by reason and status (among other criteria).
We used Molly's approach, but find we are still needing a comments field to be able to explain/report at a more detailed level.  Anyone have additional suggestions?
You could create a custom text area field on Call to Action object and then add to the CTA detail view by configuring it from Cockpit Configuration.