Reliability of the assessment of dual diagnosis (ADD).
The ADD scale is a reliable 30-item screener for psychiatric symptoms in adults with mild or moderate intellectual disability.
01Research in Context
What this study did
The team tested a new 30-item checklist called the ADD. It screens for mental-health problems in adults with mild or moderate intellectual disability.
Two raters scored the same people on different days. The study checked if scores stayed the same across time and across raters.
What they found
The ADD showed strong agreement. Test-retest and inter-rater reliability were both high. Internal consistency was also good.
In plain words, the tool gives stable, repeatable results. You can trust the score you get today will look like the score you get next week.
How this fits with other research
Irvin et al. (1998) ran a nearly identical study the same year. They tested the PAS-ADD Checklist in adults with ID and also found solid reliability. Together, the two papers show brief screeners can work.
Embregts (2000) looked at the CBCL in youth with mild ID and found poor reliability. That sounds like a clash, but the kids were younger and the tool was longer. Different age groups and item sets explain the gap.
Matson et al. (2004) later gave the PAS-ADD to a large community sample. They added normative data, building on the early reliability work started by the ADD paper.
Why it matters
You now have two quick, reliable screeners—the ADD and the PAS-ADD—for spotting psychiatric symptoms in adults with ID. Either one can flag who needs a full clinical work-up. Start your next case review by picking one, train two staff to score it independently, and use any large difference as a cue to re-interview.
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02At a glance
03Original abstract
Emotional and behavioral problems are a major source of additional handicap for children, adolescents, and adults with mental retardation. To address these problems, clinicians need psychometrically sound instruments for assessing psychopathology in individuals with mental retardation. The initial psychometric properties of the Assessment for Dual Diagnosis (ADD), a new scale designed to screen for psychopathology in individuals with mild and moderate mental retardation, was examined. The authors conducted a preliminary evaluation of the interrater and test-retest reliability of the ADD. It was determined that the ADD had high stability across raters and high stability over time. In addition, good internal consistency was established with coefficient alpha. Potential uses for the scale and directions for future research are discussed.
Research in developmental disabilities, 1998 · doi:10.1016/s0891-4222(97)00031-0