Content Validity of the Australian National Outcomes and Casemix Collection for Adult Mental Health: Linkage to the International Classification of Functioning, Disability and Health and Core Sets for Mental Health

In Australia, the National Outcomes and Casemix Collection (NOCC) provides a routine set of clinician and consumer-rated outcome measures that assess symptom severity, level of functioning, and treatment effectiveness for individuals utilising public mental health services. Concerns have been raised about the NOCC measures content validity as measures of functioning. The International Classification of Functioning Disability and Health (ICF) presents a conceptual framework and classification system that can map and evaluate the content validity of measures assessing functioning. This study used the ICF linking process to compare each NOCC measure (the Health of the Nation Outcome Scale (HoNOS), Life Skills Profile-16 (LSP-16), Kessler 10 Plus (K10 +), Behaviour and Symptom Identification Scale (BASIS-32), and Mental Health Inventory- 38 (MHI-38)) to the ICF code sets and the core sets for depression, schizophrenia, and bipolar disorder. Each battery of NOCC measures used within different jurisdictions were also compared to the Core Sets. Findings revealed that HoNOS had the best coverage of functioning across ICF code and core sets, while the K10 + demonstrated the poorest coverage. All measures were found to have gaps in ICF domains of functional assessment in the areas of body functions, activities and participation, and environmental factors. When measures were combined, the assessment of functioning was improved, with a greater proportion of codes covered from code and core sets. Still, there was inadequate coverage of environmental factors. The notable gaps in key areas of functioning across measures, especially environment factors suggest need for dedicated measures of functioning in the NOCC.