Diagnostic performance of an Executive Clock Drawing Task (CLOX) as a screening test for mild cognitive impairment in elderly persons with cognitive complaints.
BACKGROUND
CLOX, a clock drawing test protocol uniquely sensitive to impairment of executive functions, has been proposed as a screening tool for mild cognitive impairment (MCI), but data about its diagnostic efficiency are lacking.


METHODS
There are data for 196 subjects, age >or=60 years, referred to a memory clinic for cognitive complaints. After extensive neuropsychological testing, 64 were diagnosed as cognitively normal and 132 with MCI.


RESULTS
At standard cutoffs, both CLOX subtests had a fair specificity (CLOX1 72%, CLOX2 92%) but unacceptably low values of sensitivity (CLOX1 54%, CLOX2 28%) and likelihood ratio (CLOX1 1.91, CLOX2 3.59) for MCI. The use of different cutoffs or the combination of CLOX with the Mini-Mental State Examination (MMSE) did not statistically increase diagnostic efficiency.


CONCLUSIONS
CLOX, either alone or in combination with MMSE, is not a useful screening test for MCI in a clinical setting.
Forti
Paola
P
Department of Internal Medicine, Ageing, and Nephrology, University Hospital St. Orsola-Malpighi, University of Bologna, Bologna, Italy. paola.forti@unibo.it
Olivelli
Valentina
V
Rietti
Elisa
E
Maltoni
Benedetta
B
Ravaglia
Giovanni
G
D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology*; D003863:Depression / Q000523:psychology; D004493:Education; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D012372:ROC Curve