Screening for cognitive deficits with the Evaluation of Cognitive Processes involved in Disability in Schizophrenia scale.

This study aimed to evaluate the validity of the Evaluation of Cognitive Processes involved in Disability in Schizophrenia scale (ECPDS) to discriminate for cognitive impairment in schizophrenia. This multicentre cross-sectional study used a validation design with receiver operating characteristic (ROC) curve analysis. The study was undertaken in a French network of seven outward referral centres. We recruited individuals with clinically stable schizophrenia diagnosed based on the Structured Clinical Interview for assessing Diagnostic and Statistical Manual of Mental Disorders (4th ed., rev.; DSM-IV-R) criteria. The index test for cognitive impairment was ECPDS (independent variable), a 13-item scale completed by a relative of the participant. The reference standard was a standardized test battery that evaluated seven cognitive domains. Cognitive impairment was the dependent variable and was defined as an average z-score more than 1 SD below the normative mean in two or more cognitive domains. Overall, 97 patients were included (67 with schizophrenia, 28 with schizoaffective disorder, and 2 with schizophreniform disorder). The mean age was 30.2 (SD 7.7) years, and there were 75 men (77.3%). There were 59 (60.8%) patients with cognitive impairment on the neuropsychological battery, and the mean ECPDS score was 27.3 (SD 7.3). The ROC curve analysis showed that the optimal ECPDS cut-off was 29.5. The area under the curve was 0.77, with 76.3% specificity and 71.1% sensitivity to discriminate against cognitive impairment. The ECPDS is a valid triage tool for detecting cognitive impairment in schizophrenia, before using an extensive neuropsychological battery, and holds promise for use in everyday clinical practice.