If success is individually defined, there doesn't seem to be much point to AARC claiming an 85% success rate. However, it has been claimed, falsely, that the 2005 study showed that 85% of the AARC clients from the study were still sober after five years, when in fact most had not been graduated for five years, and 52% had already relapsed.
Take another look:Table 2 Longest period of
continuous sobriety of interviewed graduates, maintained by time since graduation
Time since graduation One month Six months Twelve months or more
One year or less (n=29) 0% 6.9% 93.1%
Two to three years (n=42) 2.49% 4.8% 92.9%
Four or more years (n=14) 0% 14.3% 85.7%
It was a snap shot in time. Each individual was at a different distance away from graduation. From 8 months to 5.5 years and the study showed that 85% of the people who graduate from AARC are still clean after 4 years. This is what studies are designed to do, ajax. Only a percentage of the population were at the 5 year mark.
What I would suggest is to ask someone in the company you work for or someone you know who has a statistics background to explain the table/study to you and the concept of probability. I have a resource that I us for such occasions.