New Performance-Based Tool Evaluates Cognitive Impact of Schizophrenia
A high level of internal consistency among the 4 EPICOG-SCH subtests was observed, with a Cronbach's alpha score of 0.78.
A brief cognitive battery of tests derived from the Epidemiological Study of Cognitive Impairment in Schizophrenia (EPICOG-SCH) was shown to be useful for assessing the cognitive impact of schizophrenia and may be used to monitor cognitive impairment at follow-up visits, according to the results of a study published in Schizophrenia Research: Cognition.
In this cross-sectional outpatient study, 672 patients with schizophrenia diagnosed using criteria from the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, revised, who were on stable maintenance treatment were evaluated with the EPICOG-SCH brief cognitive battery. When designing the EPICOG-SCH tool, the researchers selected 4 subtests that were relevant to the functional outcomes of cognition in schizophrenia: Letter-Number Sequencing, Digital Symbol Coding, Logical Memory, and the Category Fluency Test. The scores on the EPICOG-SCH test were then compared with scores for clinical severity and functional impairment.
A high level of internal consistency was observed among the 4 EPICOG-SCH subtests, with a Cronbach alpha score of 0.78.
EPICOG-SCH battery scores were significantly associated with overall clinical status based on Clinical Global Impression scores. Moreover, the battery scores were inversely correlated with the Clinical Global Impression subdomains Cognitive Symptoms (P <.001), Global Disease (P <.001), and Negative Symptoms (P <.001).
Functional status was also associated with EPICOG-SCH scores, with patients who were actively working receiving higher EPICOG-SCH scores than those that were not (P <.001). Cognitive battery scores also trended higher for patients involved in work requiring greater qualifications compared with those requiring fewer qualifications (P =.07).
The study authors concluded that “the EPICOG-SCH successfully achieved its objectives of serving as a brief cognitive battery that captures cognitive performance related to patients' functional outcomes in daily living using well-known classical subtests currently available in a number of countries and languages.… Furthermore, this battery is useful for monitoring cognition during routine outpatient follow-up visits.”
Zaragoza Domingo S, Bobes J, García-Portilla M-P, Morralla C. EPICOG-SCH: a brief battery to screen cognitive impact of schizophrenia in stable outpatients. Schizophr Res Cogn. 2017;8:7-20.