Editing Narcotics Anonymous (section)

=== Fiorentine 1999 ===
Fiorentine 1999 was a 24-month longitudinal study measuring the effectiveness of [[Alcoholics Anonymous]] and NA. Like other longitudinal studies, it shows a strong correlation between 12-step attendance and being both clean from drugs and sober from alcohol: People who went to 12-step meetings in the study had about a 75% success rate.

In more detail, at the 24-month follow up, 77.7% of people who went to one or more meetings a week self-reported being clean; urinalysis was very close to that figure, showing some 76.4% of the regular attendees being clean. For participants who did not regularly go to meetings, the self-reported figure for being abstinent was 56% and the drug test showed 57.9% being clean. The self-reported figures for excessive alcohol use were similar: 74.8% of regular 12-step attenders self-reported being completely sober, but only 40% of people who did not go to 12-step meetings claimed to be sober. Urinalysis showed 96.6% of people regularly going to meetings as sober, in contrast to the 88.9% of people who did not go to meetings once a week or more whose urine sample was alcohol-free.

The report then sees if 12-step meetings have a specific effect (in other words, if there is [[Correlation does not imply causation|causation or merely correlation]]) by using statistical analysis to compare participants self-reported level of motivation, 12-step attendance, and successfully getting clean and sober. The result of this observation was that "Weekly or more frequent 12-step participants are 1.59 times more likely than less-than-weekly participants to maintain abstinence after controlling for the differences in recovery motivation measured by the scale."<ref name="Fiorentine1999">{{Cite journal|year=1999|last1=Fiorentine|first1=Robert|title=After Drug Treatment: Are 12-Step Programs Effective in Maintaining Abstinence?|journal=Am J Drug Alcohol Abuse|volume=25|issue=1|pages=96–116|pmid=10078980|doi=10.1081/ADA-100101848}}</ref>