A Brief Cognitive Assessment Tool for Schizophrenia: Construction of a Tool for Clinicians

Abstract

Cognitive impairment in schizophrenia is often severe, enduring, and contributes significantly to chronic disability. But clinicians have difficulty in assessing cognition due to a lack of brief instruments. We evaluated whether a brief battery of cognitive tests derived from larger batteries could generate a summary score representing global cognitive function. Using data from 3 previously published trials, we calculated the corrected item-total correlations (CITCs) or the correlation of each test with the battery total score. We computed the proportion of variance that each test shares with the global score excluding that test (R 2 t 5CITC 2 ) and the variance explained per minute of administration time for each test (R 2 t /min). The 3 tests with the highest R 2 t /min were selected for the brief battery. The composite score from the trail making test B, category fluency, and digit symbol correlated .86 with the global score of the larger battery in 2 of the studies and correlated between .73 and .82 with the total battery scores excluding these 3 tests. A Brief Cognitive Assessment Tool for Schizophrenia (B-CATS) using the above 3 tests can be administered in 10-11 min. The full batteries of the larger studies have administration times ranging from 90 to 210 min. Given prior research suggesting that a single factor of global cognition best explains the pattern of cognitive deficit in schizophrenia, an instrument like B-CATS can provide clinicians with meaningful data regarding their patients' cognitive function. It can also serve researchers who want an estimate of global cognitive function without requiring a full neuropsychological battery.

Brief cognitive assessment instruments in schizophrenia and bipolar patients, and healthy control subjects: A comparison study between the Brief Cognitive Assessment Tool for Schizophrenia (B-CATS) and the Screen for Cognitive Impairment in Psychiatry (SCIP)

“…Regarding decision validity, both scales showed good ability to differentiate between individuals with and without cognitive impairment in terms of a global measure of cognitive functioning. Hurford et al (2009) demonstrated that the B-CATS is a brief cognitive instrument composed of well-known cognitive subtests with adequate psychometric properties. In fact, it appears to be a good choice for screening cognitive impairment in schizophrenia.…”

“…Examples are the Brief Cognitive Assessment (BCA) (Velligan et al, 2004), the Screen for Cognitive Impairment in Psychiatry (SCIP) (Purdon, 2005); and the Brief Cognitive Assessment Tool for Schizophrenia (B-CATS) (Hurford et al, 2009). These all are simple and easy-to-administer instruments that require minimal additional equipment and have shown good psychometric properties (Guilera et al, 2009;Hurford et al, 2009;Pino et al, 2008;Purdon, 2005;Rojo et al, 2010;Velligan et al, 2004). Until their advent, there were no such instruments designed for detecting cognitive deficits in psychiatric disorders in only 15 min per patient.…”

Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for the management of schizophrenia and related disorders

“…The Brief Cognitive Assessment (BCA) (Velligan et al, 2004) and the Brief Cognitive Assessment Tool for Schizophrenia (B-CATS) (Hurford et al, 2011) have sound psychometric properties and good correlations with functional measures and can be completed in 15 minutes. The Brief Assessment of Cognition in Schizophrenia (BACS) battery has good psychometric properties, has alternate forms to minimise practice effects and the composite score relates strongly to functional measures (Keefe et al, 2006a).…”

A pilot study to measure cognitive impairment in patients with severe schizophrenia with the Montreal Cognitive Assessment (MoCA)

“…A few short performance-based cognitive assessments, for example, the Brief Assessment of Cognition in Schizophrenia (BACS), the Brief Cognitive Assessment (BCA), and the Brief Cognitive Assessment Tool for Schizophrenia (B-CATS), have been developed to evaluate the general cognitive function in schizophrenia (Gold et al, 1999;Hurford et al, 2011;Keefe et al, 2004;Velligan et al, 2004). Nonetheless, the clinical usage, reliability or validity is not well established.…”