Correlation between moca and mmse for the assessment of cognition in schizophrenia

Schizophrenia (Sch) is a complex neurodevelopmental disorder associated with impairment of cognitive function as a central feature, which is confirmed by a number of studies performed on patients suffering from Sch, where clinical symptoms and social functioning of patients are consequences of neurocognitive deficits.

The goal of this study was to assess the clinical usability of the Montreal Cognitive Assessment (MoCA) as a screening instrument for cognitive impairment in schizophrenic patients, alone and in correlation with the Mini-Mental State Examination (MMSE).

This clinical prospective study included 30 patients diagnosed with schizophrenia. Patients were selected from Psychiatric Clinic, Clinical Center University of Sarajevo (CCUS) during 2010. For assessment of cognitive impairment we used Montreal Cognitive Assessment Scale (MoCA) and Mini-Mental State Examination (MMSE).

From the total number of respondents (n=30), 15/30 (50 %) were males and 15/30 (50 %) were females; age of onset were 23.5±6.69; duration of illness before hospitalization (mean±SD) 32.5±12.9. If we make a comparison of MoCA scale and MMSE under the limit values, then we get that there was 10 true positive, 4 true negative, 14 false positive and 2 false negative. This all leads to sensitivity of MoCA scale again in comparison with the MMSE of 41.7%, specificity 66.7%, positive predictive value of 83.3% and negative predictive value of 22.2%.

Our findings provide preliminary evidence that MoCA scale performs well in detecting true positive but it is imprecise in the detection of true negative findings.