Reliability of the ICD 10 version of the Psychiatric Assessment Schedule for Adults with Developmental Disability (PAS-ADD).

The Psychiatric Assessment Schedule for Adults with Developmental Disability (PAS-ADD) is a semi-structured clinical interview designed for use with respondents who have learning disability. The first version was based on the Present State Examination. The revised version was derived from the Schedules for Clinical Assessment in Neuropsychiatry (SCAN), and makes ICD 10 diagnoses using the SCAN diagnostic program. This current version has a 4-point scale of severity, compared with the 3-point scale of the first version. It also has a new module relating to psychotic disorders. The sample consisted of 40 individuals representing a spectrum of neurotic, depressive and psychotic disorders. Videotapes of 40 PAS-ADD interviews were re-rated by trained interviewers who had not been involved in the original study in which the videotapes were produced. The mean Kappa across all individual item codes was 0.65, ranging from 0.94 to 0.35. The mean Kappa agreement on item groups was 0.66. Correlation between total symptom scores was 0.74. Agreement on index of definition was Kappa 0.70. We concluded that, agreement was generally lower than for the ICD 9 version. This was probably due mainly to the increase in the severity categories from three to four. However, the new items (most of which related to psychosis) were of comparable reliability to other items.