Aspects of validity and reliability of the Neurobehavioral Cognitive Status Examination (NCSE) in assessment of psychiatric patients.

The validity and reliability of the NCSE were assessed on a sample of 192 psychiatric patients from a county general hospital with a mean age of 33.5 years and mean education of 12 years. The analyses revealed that demographic and general health factors need to be taken into consideration in interpreting the NCSE results. Predictive accuracy of the screening items for subsequent performance on metric items across different scales ranged from good to poor. A comparison of success versus failure on the screen for Construction scale with scores on metric items for this scale revealed a high number of false negative errors made using the screening item. Administration of both screen and metric items on this scale for all patients was recommended. Indices of internal consistency of the Orientation scale were adequate. A factor analysis on the scale scores extracted two factors. The second factor identified a subset of scales which assess the patients' functional capacity in dealing with the demands of everyday environment. Test-retest reliability of the NCSE assessed on a subsample of 28 subjects, was high for 7 scales, whereas low stability was demonstrated by Construction, Memory and Calculation scales (r = .79, .52 and .81, respectively). Practice effect and fluctuating attention might contribute to the low stability of these scales. These modifications in the test administration procedure would improve the accuracy of assessment of cognitive deficits in psychiatric patients.