The SAMHSA database tracks any doctor with the "X" certification to prescribe, but since that's not required when doctors are prescribing it for pain vs addiction, it makes sense that it would be primarily addiction doctors and that they don't give any way to differentiate between the types of doctors.
Of course, if I wanted to switch to Suboxone, knowing that little tidbit would actually make me more inclined to weed my way through the SAMHSA database to find a pain doctor in my area because I'd be pleased that s/he took the initiative and completed the requirements for the certification, even though technically s/he didn't
have to. But that's just me and my over-achiever appreciating self..