Abstract
Objective: We aimed to use data from the Australian Survey of Mental Health and Wellbeing to examine the psychometric properties of the Diagnostic Interview for Psychosis- Disability Module (DIP-DIS). The DIP-DIS is a semi-structured questionnaire specially designed to assess disability associated with psychotic disorders.
Method: The psychometric properties of the instrument were determined by examining its inter-rater reliability, internal structure, as well as its criterion and discriminant validities.
Results: Analysis shows: (1) that it can be rated reliably by trained interviewers, (2) that the items are complementary but tap a number of different domains, (3) that four factors account for over 66% of the variance, and (4) that it is sensitive to differing clinical populations with expected differences in level of disability. Ratings on the DIP-DIS bore significant relationships with a criterion measure of quality of life.
Conclusions: The DIP-DIS has encouraging psychometric properties for cross-sectional assessment of disability and may be useful in future studies of disablement associated with psychosis. Future work should examine its sensitivity to change.