Design and validation of a brief scale for cognitive evaluation in people with a diagnosis of schizophrenia (BCog-S)

WHAT IS KNOWN ON THE SUBJECT?: Schizophrenia is often related to cognitive deficits. Mental health nurses are involved in health promotion, prevention, treatment and rehabilitation in schizophrenia. However, the nursing literature addressing cognitive rehabilitation from schizophrenia is very limited. Cognition and its domains (communication, information processing, attentiveness, concentration, orientation, memory and calculation skills) are established by the Nursing Outcomes Classification (NOC), but they are difficult to measure. WHAT THE PAPER ADDS TO EXISTING KNOWLEDGE?: We present a new standardized cognitive assessment to be administered by nurses to people diagnosed with schizophrenia. The Brief Cognitive Scale for schizophrenia (BCog-S) was validated in people with a diagnosis of schizophrenia (including people with schizoaffective disorder), using as references both the assessment of controls matched by age, sex and educational level, and another brief cognitive battery as the gold standard. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Nurses can effectively use the BCog-S to measure cognition and its domains in people with a diagnosis of schizophrenia. It is a standardized cognitive assessment consisting of a brief battery to be administered by nurses (and other professionals) to people diagnosed with schizophrenia. It is useful for establishing normative reference values for the outcome and its indicators. Using the BCog-S, nurses can determine the cognitive status of the people diagnosed with schizophrenia they care for, measuring cognitive improvements, lapses or stability attributable to their rehabilitation. Nurses can demonstrate their contribution to cognitive rehabilitation with these measurements of improvement or stability. ABSTRACT: Introduction Nurses play a key role in cognitive rehabilitation programs for people diagnosed with schizophrenia. Aim To design and validate a brief battery to assess the cognitive status of people diagnosed with schizophrenia from the nursing perspective. Method Study developed to evaluate a diagnostic test. The Brief Cognitive Scale for schizophrenia (BCog-S) is a hybrid battery composed of previously validated brief tests, designed to meet the dimensions of cognition considered by the NOC. The psychometric properties of the instrument were measured using the Screening for Cognitive Impairment in Psychiatry-Spanish version (SCIP-S) as the gold standard, and against the scores obtained by matched controls. Results About 100 people diagnosed with schizophrenia and 100 controls participated. The battery's internal consistency was 0.70. The Pearson correlation with the SCIP-S was 0.80 (sensitivity = 0.86, specificity = 0.80). The mean T-score of those diagnosed with schizophrenia was 2.2 standard deviations below that of the controls. There were significant differences in educational level, employment and cohabitation. Discussion The BCog-S showed acceptable psychometric properties. It can discriminate cognitive impairment and could be useful for establishing normative reference values. Implications for practice Nurses can use the BCog-S to measure cognition in people with a diagnosis of schizophrenia.