Abstract
In Sweden, agencies within both the health services and the social services sectors are responsible for treatment, rehabilitation and care of persons with substance‐abuse problems. Also in the prison and probation system such problems are common among clients. The article describes how a Swedish version of the Addiction Severity Index (ASI) was developed and introduced in these three systems in the late 1990s and the extent of its implementation in regular practice. The ASI is now used for treatment‐planning and outcome‐evaluation purposes and not only for research purposes in Swedish substance‐abuse treatment agencies. A comparison of the implementation of the ASI in the three human services sectors indicates that the top‐down implementation strategies used in the prison and probation system have some important benefits, when compared with bottom‐up strategies, although such strategies are more conducive to dissemination in more decentralized human services systems. But several implementation barriers are common in all three services sectors—for example, high levels of staff turnover and competition with other structured assessment instruments. It is concluded that the prospects for a more widespread use of the ASI in the future depends—in all three human services sectors—both on the external demands for effectiveness and transparency and on internal, particularly managerial, commitment to effective services and evidence‐based practice.