Is this phrase used to change the subject? Have you used this to change the subject?
"If the conversation has suddenly gone silent, you can just go ahead and ask a completely different question. Lulls, or pauses, in conversation, happen when you’ve completely exhausted a topic, and signal that it’s time to talk about something different.
Here are some phrases you can use:
Completely changing the subject….
This has nothing to do with what we were talking about, but….
Not to change the subject, but (and change the subject).
Changing gears a little bit…
Totally unrelated…"
How to Change the Subject or Conversation Topic in English
http://englishwithkim.com/change-subject-conversation-topic-english/
Really interesting topic, thank you
I usually use this phrase when I don’t want to completely change the topic of discussion but want to add a little side point outside of it, then return to the topic at hand.
However, I think many people also use it to mean “Sorry to change the subject but…”