Studies in the United States focused on outpatients only, with alcohol withdrawal symptoms treated in the community if necessary.19 Second, it is important to advise subjects to keep a diary every day and to confirm abstinence by interviewing a cooperative attendant, as this gives the data greater credibility. In EU20–31 and US19 studies, family and friends were interviewed about the subject’s use of alcohol when possible, but in the present study a more rigorous methodology was used.