Having read serious thousands of posts on most of the SR forums, I was and remain struck by how the majority of those who have long term recovery under their belts did not spend time in rehab or IOP programs. Many found recovery in the AA and to a lesser degree NA meeting rooms. Some relied on private counseling and others on secular recovery programs.
And some seem to have gotten what they needed right here, in the SR forums.
The best prediction of success is the motivation of the patient to learn how to change their lives and apply the lessons they learned to cope with life as it is, instead of how they think it should be.