Construct validity, sensitivity and specificity of the USCD Performance-based Skill Assessment 2 in a mixed Portuguese sample

Abstract

Assessment batteries of functional capacity provide robust indicators of real-world functioning in major psychiatric illnesses and important information on an individual's ability to live autonomously and pursue relevant psychosocial goals. Objectives: This study explores the psychometric properties of the Portuguese USCD Performance-based Skill Assessment 2 (UPSA-2-PT) in a mixed sample of Portuguese participants. Method: A sample of 110 participants, 37 patients diagnosed with schizophrenia, 27 first-degree relatives of patients and 46 controls were administered the UPSA-2-PT and self-report questionnaires. The UPSA-2-PT reliability was assessed through inter-rater reliability and internal consistency, convergent validity with community integration and a receiver operating curve analysis was conducted to establish scores' sensitivity and specificity. Youden's Index was used to determine an optimal UPSA-2-PT cutoff score. Results: Findings show an excellent inter-rater reliability, good internal consistency and construct validity, consistent with previous studies in Western countries. The UPSA-2-PT also showed a good discriminant ability between patients and controls, and an overall percentage of correct classification of 86.7% based on the 81.59 cutoff. Discussion: Findings are congruous with previous versions, strengthening the body of evidence supporting the construct validity and providing a useful tool for research and clinical purposes to practitioners.