To improve treatment outcomes, it is necessary to use interventions that can motivate clients to attend treatment and initiate and sustain abstinence. Extensive research has consistently shown that client motivation for positive behavioral change can be influenced by the use of novel interventions based on established behavioral principles. In numerous controlled experimental studies in both outpatient cocaine treatment and methadone maintenance programs, procedures involving the provision of tangible incentives to clients for drug-free urines resulted in sustained periods of abstinence and retention in treatment. The initial study in Community Treatment Programs will utilize incentive values considerably lower than those typically used in research clinics.

**The data files and related study documentation were updated on December 13, 2006 to make the following changes.  Please update your files if you have already downloaded any study data/documentation:

1. A prefix was added to the deidentified patient identifier (DEIDNUM) to make analyses across trials easier.  The prefix is the trial number.

2. Formulas and derivation logic rules to the comments field in define.xml were included where possible.  Most variables are simple translations/mappings from the data source and do not require a comment.

3. Some of the graphical elements in the PDF CRF annotation were not appearing when Acrobat versions other than Acrobat 5 were used.   We have updated the PDF CRF files to alleviate this problem entirely.

**The data files and related study documentation were updated on May 8, 2007 in order to increase compliance with SDTM current standards.  Please update your files if you have already downloaded any study data/documentation.  Any analyses currently underway should not be affected with these updates.