The psychopathology instrument for mentally retarded adults: psychometric characteristics, factor structure, and relationship to subject characteristics.

The self-report and a modified informant version of the Psychopathology Instrument for Mentally Retarded Adults (PIMRA) was used to assess 160 mentally retarded adults. Statistics relating to the instrument's internal consistency and test-retest reliability were calculated. The effects of demographic variables were analyzed and the factor structure of the instrument was examined. Of the psychometric statistics examined, only the item-total correlations were as robust as in the original reports. Significant relationships between PIMRA scores and age, sex, and level of mental retardation were found, but there was no significant effect due to residential setting (institution versus community). The factor structure for both versions of the PIMRA was similar to that in the initial reports.