In 2001, the World Health Organization (WHO) created the International Classification of Functioning, Disability and Health (ICF) to offer a comprehensive and universally accepted framework to describe functioning, disability and health. The ICF Core Sets (ICF-CS) are a selection of categories that serve as a minimal standard for the assessment of functioning and disability in a specific health condition. The ICF-CS for schizophrenia was created in 2015 based on four preliminary studies that intend to capture different perspectives.

The aim of this study is to describe the similarities (i.e. overlap) and discrepancies (i.e. unique contribution) between the clinical, patient and expert perspectives on the most relevant problems in functioning of individuals with schizophrenia, being focused on the European WHO region.

Forty-four experts from 14 European countries participated in an expert survey, patients with schizophrenia were involved in four focus groups, and health professionals assessed 127 patients in relation to daily life functioning. Information gathered from these three preliminary studies was linked to the ICF.

Data showed that although a considerable number of second-level ICF categories agreed on the three preparatory studies (n=54, 27.7%), each perspective provided a unique set of ICF categories. Specifically, experts reported 65 unique ICF categories, patients 23 and health professionals 11.

Even though there were similarities between perspectives, each one underlined different areas of functioning, showing the importance of including different perspectives in order to get a complete view of functioning and disability in individuals with schizophrenia.