The validity and reliability of the Turkish version of Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) in patients with mild and moderate Alzheimer's disease and normal subjects.
OBJECTIVE
The cognitive subscale of the Alzheimer's Disease Assesment Scale (ADAS-Cog) is the most widely used test in clinical trials dealing with Alzheimer's disease (AD). The aim of this study was to investigate the validity and reliability of the Turkish version of ADAS-Cog.


METHODS
Twenty-nine patients with AD, fulfilling NINCDS-ADRDA criteria of probable AD, who were in stage 3-5 according to the Global Deterioration Scale (GDS), and 27 non-demented control subjects with similar age, gender and educational status were recruited for the study. The Turkish version of ADAS-Cog, Standardized Mini Mental Status Examination (MMSE) and Short Orientation-Memory-Concentration Test (SOMCT) were applied to both of the groups. Inter-rater reliability, internal consistency, test-retest reliability; face validity, differential validity and convergent validity were statistically analyzed.


RESULTS
Both MMSE and ADAS-Cog have significantly differentiated patients with AD and control subjects (p < 0.001). A significant correlation was established between MMSE and ADAS-Cog scores in AD group (r: -0.739). ADAS-Cog was also highly significantly correlated with GDS (r: 0.720) and SOMCT (r: 0.738). For the group with AD, control and whole cohort coefficients of internal consistency, Cronbach's alpha: 0.800, 0.515, 0.873 were found respectively. Inter-rater reliability for total ADAS-Cog score was found as ICC: 0.99 and 0.98 and test-retest reliability was found as ICC: 0.91 and 0.95 for demented and nondemented subjects, respectively.


CONCLUSIONS
The Turkish version of ADAS-Cog has been found to be highly reliable and valid in differentiating patients with mild and moderate AD from nondemented subjects.
Mavioglu
H
H
Department of Neurology, Faculty of Medicine, Celal Bayar University, Manisa, Turkey. hmavioglu@gmail.com
Gedizlioglu
M
M
Akyel
S
S
Aslaner
T
T
Eser
E
E
D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology; D003431:Cross-Cultural Comparison; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D015203:Reproducibility of Results; D014421:Turkey