The Dartmouth Assertive Community Treatment Scale (DACTS). A generalizability study

Area of Science:

• Psychometric evaluation
• Mental health services research
• Reliability analysis

Background:

• Assertive Community Treatment (ACT) is crucial for homeless mentally ill individuals.
• Reliable measurement tools are needed to evaluate ACT effectiveness.
• The Dartmouth Assertive Community Treatment Scale (DACTS) was developed for this purpose.

Purpose of the Study:

• To assess the reliability of the Dartmouth Assertive Community Treatment Scale (DACTS) using Generalizability Theory.
• To examine the sources of measurement error in DACTS scores within a national demonstration program.

Main Methods:

• Generalizability (G) theory was applied to DACTS data.
• Data were collected from program staff and local evaluators.
• Internal consistency, interrater reliability, and score stability were analyzed.

Main Results:

• The total DACTS score exhibited acceptable internal consistency and interrater reliability.
• The stability of the total DACTS score was found to be low.
• Generalizability analyses identified significant effects of site, occasion, and their interaction on DACTS reliability.

Conclusions:

• The DACTS demonstrates adequate reliability for internal consistency and interrater agreement.
• The low stability of the total score suggests caution when interpreting longitudinal changes.
• Further refinement of the DACTS or its application may be needed to enhance temporal stability.