Who Has Gone to Drug Rehab and Really Changed?

I want to know how many people out there have went willingly or forced into a drug treatment center and really made a positive change.
I left my fiance about 3 weeks ago and a few days after he got into an accident. he was charged with a DUI and child services took the kids he had custody of. he checked into a facility that is only 2 weeks long. he says he is commited to changing his life, thats wonderful but i have heard it a million times, however this is the first time he has been at an in patient rehab, he is 38 and been doing hard drugs and lots of them for 20 years. I just think he needs more than two weeks. i am pushing him to go to sober living for 6 months but he wants me to move back in and get moving on his life with his family. Hey i want that too, but its just not that easy!! What do you think? does anyone know the statistics on rehab centers?