A Computer Adaptive Testing Version of the Addiction Severity Index—Multimedia Version (ASI–MV): The Addiction Severity CAT
The purpose of this study was to develop and validate a computer adaptive testing (CAT) version of the Addiction Severity Index—Multimedia Version (ASI–MV), the Addiction Severity CAT. This goal was accomplished in 4 steps. First, new candidate items for Addiction Severity CAT domains were evaluated after brainstorming sessions with experts in substance abuse treatment. Next, this new item bank was psychometrically evaluated on a large nonclinical (n = 4,419) and substance abuse treatment (n = 845) sample. Based on these results, final items were selected and calibrated for the creation of the Addiction Severity CAT algorithms. Once the algorithms were developed for the entire assessment, a fully functioning prototype of an Addiction Severity CAT was created. CAT simulations were conducted, and optimal termination criteria were selected for the Addiction Severity CAT algorithms. Finally, construct validity of the CAT algorithms was evaluated by examining convergent and discriminant validity and sensitivity to change. The Addiction Severity CAT was determined to be valid, sensitive to change, and reliable. Further, the Addiction Severity CAT’s time of completion was found to be significantly less than the average time of completion for the ASI–MV composite scores. This study represents the initial validation of an Addiction Severity CAT based on item response theory, and further exploration of the Addiction Severity CAT is needed.