Itemmetric and scale analysis of a new computer-assisted competency assessment instrument (CADCOMP)

Male defendants (n = 99) who had been court ordered to a forensic treatment facility as incompetent to stand trial were tested using the Computer-Assisted Determination of Competency to Proceed (CADCOMP) instrument soon after admission (median days = 15). Shortly thereafter, competency was assessed by a forensic psychiatrist and by a majority decision of three mental health professionals who viewed a videotape of the forensic psychiatrist's interview. From the CADCOMP item pool, 18 scales were constructed on conceptual grounds. Internal consistency analyses revealed that most scales had reasonable item homogeneity and scale reliability. In addition, item and scale analyses, with few exceptions, followed predicted patterns of intercorrelation and association with competency as determined by both criteria. Scales and items measuring serious psychopathology, psycholegal ability, and criminal history demonstrated the strongest associations with competency. These findings suggest that additional research on CADCOMP is warranted. The instrument shows promise for use in forensic research and assessment.