Validation of the SPF-10: A new scale for assessing self-perceived functioning in schizophrenia. The VALFASS study.

The VALFASS study evaluated the SPF-10, a new 10-item patient-reported outcome measure developed with direct patient involvement to assess self-perceived functioning in schizophrenia. Covering autonomy, relationships, occupation, independence, and everyday capabilities, the SPF-10 was designed to address limitations of existing instruments, including limited patient input, reduced feasibility for routine use, and incomplete capture of the patient perspective. This cross-sectional, multicenter study included 155 participants: 44 recently exacerbated patients with schizophrenia, 55 clinically stable patients, and 56 healthy controls. The SPF-10 showed excellent feasibility, with a 100% item response rate and a median completion time of 5 min. Exploratory factor analysis supported a two-dimensional structure, Personal and Social Relationships and Self-Care and Capabilities, explaining 57.7% of the variance. The total SPF-10 score discriminated well between patients and controls (AUC = 0.888) and between patients with moderate-to-severe functional impairment and those with mild or no impairment (AUC = 0.851). A cut-off score of ≤32 yielded 80.8% sensitivity, 84.4% specificity, and 82.6% overall correct classification. Correlations with clinician-rated functioning measures were moderate (PSP r = 0.559; GAF r = 0.521), supporting its complementary value, and internal consistency was good in both patients and controls (Cronbach's α = 0.868 and 0.838, respectively). Overall, the SPF-10 showed adequate psychometric performance and high clinical applicability. Its brief format, patient-centered development, and ability to capture aspects of functioning not fully reflected by clinician-rated instruments support its potential value as a complementary tool for person-centered assessment and care planning in schizophrenia.