Assessment of functioning in patients with schizophrenia and schizoaffective disorder with the Mini-ICF-APP: a validation study in Italy

Background: The aim of the study was to evaluate validity of the Italian Mini-ICF-APP (Mini-ICF Rating for Limitations of Activities and Participation in Psychological Disorders) in schizophrenia and related disorders. Methods: 74 outpatients affected by schizophrenia or schizoaffective disorders attending a University-based community mental health centre were recruited to the study. All participants underwent comprehensive evaluation using standardized instruments to assess clinical, neurocognitive and functional status. Concurrent validity of Mini-ICF-APP was evaluated and compared to severity scores obtained using the Clinical Global Impression-Schizophrenia scale (CGI-SCH), Positive and Negative Syndrome scale (PANSS), Mini Mental State Examination test (MMSE), Brief Assessment of Cognition in Schizophrenia scale (BACS) and Personal and Social Performance scale (PSP). Construct validity was evaluated by comparing scores obtained at Mini-ICF-APP by remitted versus non-remitted patients, and by recovered versus unrecovered patients. Discriminant validity was evaluated comparing scores on Mini-ICF-APP and Subjective Well-being (SWN) scale. Results: the total score and 12 out of the 13 Mini-ICF-APP items correlated significantly with total score at PSP; Mini-ICF-App total score was moreover significantly correlated with total scores at CGI-SCH, PANSS, MMSE, as well as with several BACS items. Total scores obtained at Mini-ICF-APP were significantly higher among remitted and recovered patients. No relevant correlations were found between scores of Mini-ICF-APP and SWN scales. Results: The total score and 12 out of the 13 Mini-ICF-APP items correlated significantly with total score at PSP; Mini-ICF-App total score was moreover significantly correlated with total scores at CGI-SCH, PANSS, MMSE, as well as with several BACS items. Total scores obtained at Mini-ICF-APP were significantly higher among remitted and recovered patients. No relevant correlations were found between scores of Mini-ICF-APP and SWN scales. Conclusion: the Italian version of Mini-ICF-APP is a valid instrument for use in evaluating functioning in chronic patients with schizophrenia and related disorders.