Short cognitive test (SCOT): a screening instrument to measure cognitive impairment in patients with schizophrenia and bipolar disorder (a pilot study)
Abstract
Cognitive functions and their impairment in schizophrenia and bipolar disorder have become recently the focus of attention of researchers and clinicians. Cognitive deficit has a negative impact on patients functioning.
In our pilot study, we used original screening tool, Short Cognitive Test (SCOT), developed and adapted from an earlier Swedish test. Study aims were to examine basic psychometric properties of SCOT, to compare results of schizophrenia and bipolar patients with those obtained from healthy controls, and to correlate SCOT scores with the PANSS cognitive subscale (PANSS-cog) and Global Assessment of Functioning (GAF).
Study sample consisted of 30 patients and 25 control subjects. The results showed that patients had significantly lower SCOT scores as compared to controls (p < 0.001).
Furthermore, in the patients group SCOT score correlated significantly with the PANSS-cog (p = 0.009) and GAF (p = 0.017). SCOT also yielded good reliability (split-half reliability 0.780).
Using cut-off score of 14 to delineate cognitive impairment, sensitivity, specificity, positive and negative prediction values resulted in the most optimal parameters. Our pilot study confirmed that SCOT can be easily administered in the clinical setting (testing and evaluation takes up to 10 minutes), the test showed constructive validity (testing of memory, executive functions, and abstraction), convergent validity (correlation with the PANSS-cog), and ecological validity (correlation with GAF), with a good reliability.
In order to definitely assess contribution of SCOT, a representative sample of schizophrenia and bipolar patients who will be tested also with standard neuropsychological measures to verify cognitive deficit, is needed