Initial validity and reliability of the SCCAN: using tailored testing to assess adult cognition and communication.

PURPOSE

The Scales of Cognitive and Communicative Ability for Neurorehabilitation (SCCAN; L. Milman & A. Holland, 2007) was developed in the hospital setting to address changes in assessment practice. The SCCAN was designed to provide an overview of impairment and activity limitations across 8 cognitive scales (Speech Comprehension, Oral Expression, Reading, Writing, Orientation, Attention, Memory, and Problem Solving). The scales were developed using item response theory so that tailored testing could be implemented to reduce test administration time. This research investigated the validity and reliability of the SCCAN.

METHOD

A battery of neuropsychological tests was administered to 40 neurologically healthy control participants and 51 participants diagnosed with left-hemisphere pathology, right-hemisphere pathology, or probable Alzheimer's disease. Analyses were performed to assess test sensitivity and specificity, construct validity, administration time, and reliability.

RESULTS

The test accurately classified 95% of the control participants and 98% of the participants diagnosed with neurological disorders. Results indicate that the test also differentiated the performance profiles of the 3 clinical populations. In addition, test scores correlated significantly with external measures of the same cognitive areas. Mean administration time was 34 min. Test-retest stability (r = .96, p < .001) and internal consistency (r = .99, p < .001) coefficients were both significant, indicating that tailored testing procedures generated reliable test scores.