The assessment of patients with long-term psychotic disorders: application of the WHO Disability Assessment Schedule II

Abstract

Objectives: To evaluate the use of the World Health Organization Disability Assessment Schedule II (WHODAS II), a patient questionnaire measuring disability, in patients treated for long-term psychotic disorders.

Method: The study was conducted at St. Vincent's Mental Health Service, Melbourne, Australia. Twenty patients with long-term psychotic disorders under the care of either the residential Community Care Unit or the outpatient Mobile Support and Treatment Service were selected. For all 20 patients a clinician assessment of disability and functional status was recorded using the International Classification of Impairments, Disabilities and Handicaps-2 (ICIDH-2), Life Skills Profile (LSP) and Health of the Nation Outcome Scale (HoNOS). The WHODAS II survey was then administered to each patient. The WHODAS II was re-administered by a second rater within 5 days of the initial assessment for the purpose of test-retest reliability analysis. Each patient also completed the WHO Quality of Life instrument (brief version) (WHQOL-BREF), a self-report questionnaire on quality of life.

Results: The WHODAS II was experienced as relatively complex and at times difficult to administer with full co-operation in this clinical context. Overall, test-retest reliability was fair. The information it yielded gave valuable insights into patients' experiences. Most of the participants reported fewer impairments in mental functions and fewer activity limitations than reported by clinicians. However, patients reported significant restrictions in participation in social activities and limitations due to environmental barriers. The WHOQOL-BREF highlighted difficulties experienced by patients in their participation in society, through exploring difficulties and satisfaction with various aspects of life experience and this instrument was well accepted.

Conclusions: The self-reported experience of patients is needed alongside clinician-rated measures to assess outcomes in people with long-term psychotic disorders. The WHODAS II records and measures patients' own experiences of disability. It may be used together with the WHOQOL-BREF, a distinct and complementary self-report assessment of quality of life.