AbstractPurposeThis study was performed to identify the predictive factors of functional capacity assessed by the Spanish University of California Performance Skills Assessment (Sp-UPSA) and real-world functioning assessed by the Spanish Personal and Social Performance scale (PSP) in outpatients with schizophrenia.MethodsNaturalistic, 6-month follow-up, multicentre, validation study. Here, we report data on 139 patients with schizophrenia at their baseline visit. Assessment: Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression-Severity (CGI-S), Sp-UPSA and PSP. Statistics: Pearson's correlation coefficient (r) was used to determine the relationships between variables, and multivariable stepwise linear regression analyses to identify predictive variables of Sp-UPSA and PSP total scores.ResultsFunctional capacity: scores on the PSP and PANSS-GP entered first and second atP< 0.0001 and accounted for 21% of variance (R²= 0.208, modeldf= 2,F= 15.724,P< 0.0001). Real-world functioning: scores on the CGI-S (B= −5.406), PANSS-N (B= −0.657) and Sp-UPSA (B= 0.230) entered first, second and third, and accounted for 51% of variance (modeldf= 3,F= 37.741,P< 0.0001).ConclusionIn patients with schizophrenia, functional capacity and real-world functioning are two related but different constructs. Each one predicts the other along with other factors; general psychopathology for functional capacity, and severity of the illness and negative symptoms for real-world functioning. These findings have important clinical implications: (1) both types of functioning should be assessed in patients with schizophrenia and (2) strategies for improving them should be different.