Diagnostic performance and cutoff value for the clock drawing test, semantic verbal fluency, and the short Boston Naming Test in community-dwelling educated older adults with neurocognitive disorders

Background Little is known regarding the standardized neuropsychological tests available in Arabic. The aim is to determine the diagnostic performance and the best cutoff value for the clock drawing test (CDT), animal category test of semantic verbal fluency (VF), and the short form of the Boston Naming Test (BNT) in identifying patients with mild and major neurocognitive disorders among community-dwelling educated Egyptian older adults using Arabic versions of those tests. Community-dwelling educated male and female older adults aged 60 years or older. Successive patients were attending the outpatient geriatrics clinic at the Ain Shams University Hospital during a 12-month study period from January to December 2016. The study was approved by the ethics committee of the Faculty of Medicine, Ain Shams University, Cairo, Egypt. Informed consent to participate in the study was received from each participant and/or his/her next of kin. Patients and/or their next of kin who declined to participate were excluded, as were those who refused to complete the assessment. A two-step protocol was followed. Step 1: Participants were divided into three groups according to DSM-V diagnostic criteria for neurocognitive disorders. The assessment of cognitive function included Mini-Mental State Examination (MMSE), Clinical Dementia Rating Scale (CDR), patient's current functional status regarding basic and instrumental activities of daily living by the Blessed Dementia Scale (BDS), and patient detailed history and examination based on protocol five of the CERAD assessment packet. Step 2: The application of the Arabic versions of ELokl et al. 2001 VF test, the BNT, and the CD by a clinical psychologist blinded to the initial assessment results. Results In current study, AUC for CD, VF, and BN are 0.807, 0.77, and 0.753 respectively for mild NCD and 0.884, 0.877, and 0.839 respectively for major NCD while cutoff values for CD, VF, and BN are 2, 12, and 14 respectively for mild NCD and 2, 9, and 13 respectively for major NCD. Conclusion Verbal fluency, clock drawing, and Boston naming showed reasonable diagnostic performance in educated Egyptian elderly and should be considered separately or in combination for the assessment of cognitive function. Further research is warranted.