Analyses of the TCU drug screen 5: using an item response theory model with a sample of juvenile justice youth

It is important to identify substance use disorders among youth who enter the juvenile justice system using a validated screener, such as the Texas Christian University Drug Screen 5 (TCU DS 5), so that necessary services can be provided to youth in need of treatment. While the TCU DS 5 is a valid, evidence-based screener, the use of an Item Response Theory model may better differentiate between mild, moderate, and severe forms of substance use disorders. The current study analyzed the feasibility and incremental value gained in using an Item Response Theory model to compute drug use severity scores as compared to its current scoring methodology. Results showed that while Item Response Theory may not be worthwhile as the standard method of scoring, item level analyses revealed there are benefits to using Item Response Theory to determine which items on a screener are most suggestive of severe substance use problems.