Alcoholics Anonymous (AA) is an international peer-led mutual aid fellowship dedicated to abstinence-based recovery from alcoholism through its spiritually-inclined Twelve Step program. Following its Twelve Traditions AA is non-professional and non-denominational, as well as apolitical and unaffiliated. In 2020 AA estimated its worldwide membership to be over two million with 75% of those in the U.S. and Canada. Regarding its effectiveness, a 2020 scientific review saw clinical interventions encouraging increased AA participation resulting in higher abstinence rates over other clinical interventions, and most studies in the review showed AA led to lower health costs. While AA has no opinion on the disease model of alcoholism—or on any medical matter, the large role of many members in popularizing it has led to its association with AA. AA dates its start to 1935 with Bill Wilson (Bill W) first commiserating alcoholic to alcoholic with Bob Smith (Dr. Bob) who, along with Wilson, was active in AA's immediate precursor the Christian revivalist Oxford Group. Within the Oxford Group Wilson and Smith, joined by other alcoholics, supported each other in meetings and one on one until breaking off to form a fellowship of alcoholics only. In 1939 they published Alcoholics Anonymous: The Story of How More Than One Hundred Men Have Recovered From Alcoholism. Known as the "Big Book" and the source of AA’s name, it contains AA's Twelve Step recovery program. Subsequent editions included the Twelve Traditions adopted in 1950 to formalize and unify the fellowship which Wilson called “a benign anarchy”. The Twelve Steps are presented as a suggested self-improvement program resulting in a spiritual awakening after an alcoholic has conceded powerlessness over alcohol and acknowledged its damage, as well as having listed and strived to correct personal failings and by making amends for misdeeds. After completing the Steps they suggest members take other alcoholics through them. Though not explicitly prescribed, this is often done by sponsoring other alcoholics. Discovering and following the will of God—"as we understood Him"— is also urged by the Steps, but differing spiritual practices and persuasions, as well as non-theist members, are accepted and accommodated. The Twelve Traditions are AA's advisory guidelines for members, groups and to its non-governing service structure. Besides making a desire to stop drinking the only membership requirement, the Traditions advise against dogma, hierarchies and involvement in public controversies so recovery from alcoholism remains AA’s primary purpose. Without threat of retribution or means