Figure 2 shows a Kaplan-Meier analysis with a log-rank test for one of the secondary outcome measures: the time elapsed from initiation of the study drug to the first relapse. Although no significant difference was observed between the 2 groups, a higher proportion of subjects in the acamprosate group maintained complete abstinence throughout the study period (treatment period, P = .060; follow-up period, P = .123; log-rank test).