How do I find out the success rate of substance abuse recovery programs?

It's virtually impossible to find out the actual success (or failure) rate of a recovery program. Data from AA indicates that its success rate is about 5% at the end of one year. That's actually less than the spontaneous remission (natural cure) rate from attending no program.

Programs largely present estimates as facts, look at short-term rather than long-term success, define success in terms that benefit themselves, and generally use deceptive or dishonest figures.

It's a case of "buyer beware."